TY - JOUR T1 - Conservation laws for free-boundary fluid layers JF - SIAM J. Appl. Math. Y1 - 2021 A1 - E. Bueler VL - 81 ER - TY - BOOK T1 - PETSc for Partial Differential Equations: Numerical Solutions in C and Python Y1 - 2021 A1 - E. Bueler PB - SIAM Press CY - Philadelphia UR - https://my.siam.org/Store/Product/viewproduct/?ProductId=32850137 ER - TY - JOUR T1 - Circumpolar Deep Water Impacts Glacial Meltwater Export and Coastal Biogeochemical Cycling Along the West Antarctic Peninsula JF - Frontiers in Marine Science Y1 - 2019 A1 - Cape, Mattias R. A1 - Vernet, Maria A1 - Pettit, Erin C. A1 - Wellner, Julia A1 - Truffer, Martin A1 - Akie, Garrett A1 - Domack, Eugene A1 - Leventer, Amy A1 - Smith, Craig R. A1 - Huber, Bruce A. KW - Antarctic Peninsula KW - ice KW - meltwater KW - phytoplankton VL - 6 UR - https://www.frontiersin.org/article/10.3389/fmars.2019.00144/full ER - TY - JOUR T1 - Contribution of the Greenland Ice Sheet to sea level over the next millennium JF - Science Advances Y1 - 2019 A1 - Aschwanden, Andy A1 - Fahnestock, Mark A. A1 - Truffer, Martin A1 - Brinkerhoff, Douglas J. A1 - Hock, Regine A1 - Khroulev, Constantine A1 - Mottram, Ruth A1 - Khan, S. Abbas AB - The Greenland Ice Sheet holds 7.2 m of sea level equivalent and in recent decades, rising temperatures have led to accelerated mass loss. Current ice margin recession is led by the retreat of outlet glaciers, large rivers of ice ending in narrow fjords that drain the interior. We pair an outlet glacier–resolving ice sheet model with a comprehensive uncertainty quantification to estimate Greenland's contribution to sea level over the next millennium. We find that Greenland could contribute 5 to 33 cm to sea level by 2100, with discharge from outlet glaciers contributing 8 to 45% of total mass loss. Our analysis shows that uncertainties in projecting mass loss are dominated by uncertainties in climate scenarios and surface processes, whereas uncertainties in calving and frontal melt play a minor role. We project that Greenland will very likely become ice free within a millennium without substantial reductions in greenhouse gas emissions. VL - 5 UR - http://advances.sciencemag.org/lookup/doi/10.1126/sciadv.aav9396 ER - TY - JOUR T1 - The Larsen Ice Shelf System, Antarctica (LARISSA): Polar Systems Bound Together, Changing Fast JF - GSA Today Y1 - 2019 A1 - Wellner, Julia A1 - Scambos, Ted A1 - Domack, Eugene A1 - Vernet, Maria A1 - Leventer, Amy A1 - Balco, Greg A1 - Brachfeld, Stefanie A1 - Cape, Mattias A1 - Huber, Bruce A1 - Ishman, Scott A1 - McCormick, Michael A1 - Mosley-Thompson, Ellen A1 - Pettit, Erin A1 - Smith, Craig A1 - Truffer, Martin A1 - Van Dover, Cindy A1 - Yoo, Kyu-Cheul AB - Climatic, cryospheric, and biologic changes taking place in the northern Antarctic Peninsula provide examples for how ongoing systemic change may pro‐ gress through the entire Antarctic system. A large, interdisciplinary research project focused on the Larsen Ice Shelf system, synthesized here, has documented dramatic ice cover, oceanographic, and ecosystem changes in the Antarctic Peninsula during the Holocene and the present period of rapid regional warming. The responsive- ness of the region results from its position in the climate and ocean system, in which a narrow continental block extends across zonal atmospheric and ocean flow, creating high snow accumulation, strong gradients and gyres, dynamic oceanography, outlet glaciers feeding into many fjords and bays having steep topography, and a continental shelf that contains many glacially carved troughs separated by areas of glacial sedi- ment accumulation. The microcosm of the northern Antarctic Peninsula has a ten- dency to change rapidly—rapid relative not just to Antarctica's mainland but compared to the rest of the planet as well—and it is generally warmer than the rest of Antarctica. Both its Holocene and modern glaciological retreats offer a picture of how larger areas of Antarctica farther south might change under future warming. VL - 29 ER - TY - JOUR T1 - Non-linear glacier response to calving events, Jakobshavn Isbræ, Greenland JF - Journal of Glaciology Y1 - 2019 A1 - Cassotto, Ryan A1 - Fahnestock, Mark A1 - Amundson, Jason M. A1 - Truffer, Martin A1 - Boettcher, Margaret S. A1 - De La Peña, Santiago A1 - Howat, Ian KW - calving KW - dynamic thinning KW - Jakobshavn Isbræ KW - terrestrial radar interferometry KW - tidewater glaciers AB - Jakobshavn Isbræ, a tidewater glacier that produces some of Greenland's largest icebergs and highest speeds, reached record-high flow rates in 2012 (Joughin and others, 2014). We use terrestrial radar interferometric observations from August 2012 to characterize the events that led to record-high flow. We find that the highest speeds occurred in response to a small calving retreat, while several larger calving events produced negligible changes in glacier speed. This non-linear response to calving events suggests the terminus was close to flotation and therefore highly sensitive to terminus position. Our observations indicate that a glacier's response to calving is a consequence of two competing feedbacks: (1) an increase in strain rates that leads to dynamic thinning and faster flow, thereby promoting destabilization, and (2) an increase in flow rates that advects thick ice toward the terminus and promotes restabilization. The competition between these feedbacks depends on temporal and spatial variations in the glacier's proximity to flotation. This study highlights the importance of dynamic thinning and advective processes on tidewater glacier stability, and further suggests the latter may be limiting the current retreat due to the thick ice that occupies Jakobshavn Isbræ's retrograde bed. VL - 65 ER - TY - JOUR T1 - Simulated Greenland Surface Mass Balance in the GISS ModelE2 GCM: Role of the Ice Sheet Surface JF - Journal of Geophysical Research: Earth Surface Y1 - 2019 A1 - Alexander, P. M. A1 - LeGrande, A. N. A1 - Fischer, E. A1 - Tedesco, M. A1 - Fettweis, X. A1 - Kelley, M. A1 - Nowicki, S. M. J. A1 - Schmidt, G. A. KW - 1911-UW AB - The rate of growth or retreat of the Greenland and Antarctic ice sheets remains a highly uncertain component of future sea level change. Here we examine the simulation of Greenland ice sheet surface mass balance (GrIS SMB) in a development branch of the ModelE2 version of the NASA Goddard Institute for Space Studies (GISS) general circulation model (GCM). GCMs are often limited in their ability to represent SMB compared with polar region regional climate models. We compare ModelE2‐simulated GrIS SMB for present‐day (1996–2005) simulations with fixed ocean conditions, at a spatial resolution of 2° latitude by 2.5° longitude ({\textasciitilde}200 km), with SMB simulated by the Modèle Atmosphérique Régionale (MAR) regional climate model (1996–2005 at a 25‐km resolution). ModelE2 SMB agrees well with MAR SMB on the whole, but there are distinct spatial patterns of differences and large differences in some SMB components. The impacts of changes to the ModelE2 surface are tested, including a subgrid‐scale representation of SMB with surface elevation classes. This has a minimal effect on ice sheet‐wide SMB but corrects local biases. Replacing fixed surface albedo with satellite‐derived values and an age‐dependent scheme has a larger impact, increasing simulated melt by 60%–100%. We also find that lower surface albedo can enhance the effects of elevation classes. Reducing ModelE2 surface roughness length to values closer to MAR reduces sublimation by {\textasciitilde}50%. Further work is required to account for meltwater refreezing in ModelE2 and to understand how differences in atmospheric processes and model resolution influence simulated SMB. Plain Language Summary Melting of the Earth's ice sheets represents a substantial contribution to global sea level rise. Global climate model simulations of Earth's climate often model the surface of ice sheets in a fairly simple way because of computational limitations. This study evaluates the representation of the Greenland ice sheet in one such global model simulation (from the NASA Goddard Institute for Space Studies general circulation model) against a regional model that simulates only the local Greenland area in a higher degree of detail. The study finds that the global model simulation of the Greenland ice sheet is sensitive to how the model represents the ice sheet surface, in particular, how it reflects incoming sunlight, stores and freezes liquid water, and simulates surface evaporation. Attempting to improve the simulation by dividing the ice sheet surface into additional grid cells according to surface elevation has a minor impact on the simulation. The study reveals how the representation of the Greenland ice sheet in ModelE2 might be improved to better estimate ice sheet change and the sea level response to global climate changes. VL - 124 UR - https://onlinelibrary.wiley.com/doi/abs/10.1029/2018JF004772 ER - TY - JOUR T1 - Spatio-temporal variations in seasonal ice tongue submarine melt rate at a tidewater glacier in southwest Greenland JF - J. Glaciol. Y1 - 2019 A1 - Moyer, A N A1 - Nienow, P W A1 - Gourmelen, N A1 - Sole, A J A1 - Truffer, M A1 - Fahnestock, M A1 - Slater, D A KW - glacier calving KW - ice KW - ocean interactions KW - Remote sensing KW - subglacial processes ER - TY - JOUR T1 - Tracking icebergs with time-lapse photography and sparse optical flow , LeConte Bay , Alaska , 2016 – 2017 JF - J. Glaciol. Y1 - 2019 A1 - Kienholz, Christian A1 - Amundson, Jason M A1 - Motyka, Roman J A1 - Jackson, Rebecca H A1 - Mickett, John B A1 - Sutherland, David A A1 - Nash, Jonathan D A1 - Winters, Dylan S A1 - Dryer, William P A1 - Truffer, Martin KW - glaciological instruments and methods KW - ice KW - icebergs KW - ocean interactions KW - Remote sensing VL - 65 ER - TY - JOUR T1 - Active seismic studies in valley glacier settings: strategies and limitations JF - Journal of Glaciology Y1 - 2018 A1 - ZECHMANN, JENNA M. A1 - BOOTH, ADAM D. A1 - Truffer, Martin A1 - Gusmeroli, Alessio A1 - Amundson, Jason M. A1 - Larsen, Christopher F. KW - glacial tills KW - glacier geophysics KW - glaciological instruments and methods KW - seismics KW - subglacial AB - Subglacial tills play an important role in glacier dynamics but are difficult to characterize in situ. Amplitude Variation with Angle (AVA) analysis of seismic reflection data can distinguish between stiff tills and deformable tills. However, AVA analysis in mountain glacier environments can be problematic: reflections can be obscured by Rayleigh wave energy scattered from crevasses, and complex basal topography can impede the location of reflection points in 2-D acquisitions. We use a forward model to produce challenging synthetic seismic records in order to test the efficacy of AVA in crevassed and geometrically complex environments. We find that we can distinguish subglacial till types in moderately crevassed environments, where ‘moderate' depends on crevasse spacing and orientation. The forward model serves as a planning tool, as it can predict AVA success or failure based on characteristics of the study glacier. Applying lessons from the forward model, we perform AVA on a seismic dataset collected from Taku Glacier in Southeast Alaska in March 2016. Taku Glacier is a valley glacier thought to overlay thick sediment deposits. A near-offset polarity reversal confirms that the tills are deformable. VL - 64 UR - https://www.cambridge.org/core/product/identifier/S0022143018000692/type/journal{\_}article ER - TY - JOUR T1 - Design and results of the ice sheet model initialisation experiments initMIP-Greenland: an ISMIP6 intercomparison JF - The Cryosphere Y1 - 2018 A1 - Goelzer, Heiko A1 - Nowicki, Sophie A1 - Edwards, Tamsin A1 - Beckley, Matthew A1 - Abe-Ouchi, Ayako A1 - Aschwanden, Andy A1 - Calov, Reinhard A1 - Gagliardini, Olivier A1 - Gillet-Chaulet, Fabien A1 - Golledge, Nicholas R. A1 - Gregory, Jonathan A1 - Greve, Ralf A1 - Humbert, Angelika A1 - Huybrechts, Philippe A1 - Kennedy, Joseph H. A1 - Larour, Eric A1 - Lipscomb, William H. A1 - Le clec'h, Sébastien A1 - Lee, Victoria A1 - Morlighem, Mathieu A1 - Pattyn, Frank A1 - Payne, Antony J. A1 - Rodehacke, Christian A1 - Rückamp, Martin A1 - Saito, Fuyuki A1 - Schlegel, Nicole A1 - Seroussi, Helene A1 - Shepherd, Andrew A1 - Sun, Sainan A1 - van de Wal, Roderik A1 - Ziemen, Florian A. AB - Abstract. Earlier large-scale Greenland ice sheet sea-level projections (e.g. those run during the ice2sea and SeaRISE initiatives) have shown that ice sheet initial conditions have a large effect on the projections and give rise to important uncertainties. The goal of this initMIP-Greenland intercomparison exercise is to compare, evaluate, and improve the initialisation techniques used in the ice sheet modelling community and to estimate the associated uncertainties in modelled mass changes. initMIP-Greenland is the first in a series of ice sheet model intercomparison activities within ISMIP6 (the Ice Sheet Model Intercomparison Project for CMIP6), which is the primary activity within the Coupled Model Intercomparison Project Phase 6 (CMIP6) focusing on the ice sheets. Two experiments for the large-scale Greenland ice sheet have been designed to allow intercomparison between participating models of (1) the initial present-day state of the ice sheet and (2) the response in two idealised forward experiments. The forward experiments serve to evaluate the initialisation in terms of model drift (forward run without additional forcing) and in response to a large perturbation (prescribed surface mass balance anomaly); they should not be interpreted as sea-level projections. We present and discuss results that highlight the diversity of data sets, boundary conditions, and initialisation techniques used in the community to generate initial states of the Greenland ice sheet. We find good agreement across the ensemble for the dynamic response to surface mass balance changes in areas where the simulated ice sheets overlap but differences arising from the initial size of the ice sheet. The model drift in the control experiment is reduced for models that participated in earlier intercomparison exercises. VL - 12 UR - https://www.the-cryosphere.net/12/1433/2018/ ER - TY - JOUR T1 - A large impact crater beneath Hiawatha Glacier in northwest Greenland JF - Science Advances Y1 - 2018 A1 - Kjær, Kurt H. A1 - Larsen, Nicolaj K A1 - Binder, Tobias A1 - Bjørk, Anders A A1 - Eisen, Olaf A1 - Fahnestock, Mark A A1 - Funder, Svend A1 - Garde, Adam A A1 - Haack, Henning A1 - Helm, Veit A1 - Houmark-Nielsen, Michael A1 - Kjeldsen, Kristian K A1 - Khan, Shfaqat A A1 - Machguth, Horst A1 - McDonald, Iain A1 - Morlighem, Mathieu A1 - Mouginot, Jérémie A1 - Paden, John D A1 - Waight, Tod E A1 - Weikusat, Christian A1 - Willerslev, Eske A1 - MacGregor, Joseph A. AB - We report the discovery of a large impact crater beneath Hiawatha Glacier in northwest Greenland. From airborne radar surveys, we identify a 31-kilometer-wide, circular bedrock depression beneath up to a kilometer of ice. This depression has an elevated rim that cross-cuts tributary subglacial channels and a subdued central uplift that appears to be actively eroding. From ground investigations of the deglaciated foreland, we identify overprinted structures within Precambrian bedrock along the ice margin that strike tangent to the subglacial rim. Glaciofluvial sediment from the largest river draining the crater contains shocked quartz and other impact-related grains. Geochemical analysis of this sediment indicates that the impactor was a fractionated iron asteroid, which must have been more than a kilometer wide to produce the identified crater. Radiostratigraphy of the ice in the crater shows that the Holocene ice is continuous and conformable, but all deeper and older ice appears to be debris rich or heavily disturbed. The age of this impact crater is presently unknown, but from our geological and geophysical evidence, we conclude that it is unlikely to predate the Pleistocene inception of the Greenland Ice Sheet. VL - 4 UR - http://advances.sciencemag.org/ http://advances.sciencemag.org/lookup/doi/10.1126/sciadv.aar8173 ER - TY - JOUR T1 - Modeling Winter Precipitation Over the Juneau Icefield, Alaska, Using a Linear Model of Orographic Precipitation JF - Frontiers in Earth Science Y1 - 2018 A1 - Roth, Aurora A1 - Hock, Regine A1 - Schuler, Thomas V. A1 - Bieniek, Peter A. A1 - Pelto, Mauri A1 - Aschwanden, Andy KW - Alaska KW - downscaling KW - glacier mass balance KW - Juneau Icefield KW - Modeling KW - orographic precipitation KW - snow accumulation VL - 6 UR - http://journal.frontiersin.org/article/10.3389/feart.2018.00020/full ER - TY - JOUR T1 - Acquisition of a 3 min, two-dimensional glacier velocity field with terrestrial radar interferometry JF - Journal of Glaciology Y1 - 2017 A1 - Voytenko, Denis A1 - Dixon, Timothy H. A1 - Holland, David M. A1 - Cassotto, Ryan A1 - Howat, Ian M. A1 - Fahnestock, Mark A. A1 - Truffer, Martin A1 - De La Peña, Santiago KW - glacier flow KW - glacier geophysics KW - glaciological instruments and methods AB - {\textless}p{\textgreater}Outlet glaciers undergo rapid spatial and temporal changes in flow velocity during calving events. Observing such changes requires both high temporal and high spatial resolution methods, something now possible with terrestrial radar interferometry. While a single such radar provides line-of-sight velocity, two radars define both components of the horizontal flow field. To assess the feasibility of obtaining the two-dimensional (2-D) flow field, we deployed two terrestrial radar interferometers at Jakobshavn Isbrae, a major outlet glacier on Greenland's west coast, in the summer of 2012. Here, we develop and demonstrate a method to combine the line-of-sight velocity data from two synchronized radars to produce a 2-D velocity field from a single (3 min) interferogram. Results are compared with the more traditional feature-tracking data obtained from the same radar, averaged over a longer period. We demonstrate the potential and limitations of this new dual-radar approach for obtaining high spatial and temporal resolution 2-D velocity fields at outlet glaciers.{\textless}/p{\textgreater} UR - https://www.cambridge.org/core/product/identifier/S0022143017000284/type/journal{\_}article ER - TY - JOUR T1 - Asynchronous behavior of outlet glaciers feeding Godth\aabsfjord (Nuup Kangerlua) and the triggering of Narsap Sermia's retreat in SW Greenland JF - J. Glaciol. Y1 - 2017 A1 - Motyka, Roman J. A1 - Cassotto, Ryan A1 - Truffer, Martin A1 - Kjeldsen, Kristian K. A1 - Van As, Dirk A1 - Korsgaard, Niels J. A1 - Fahnestock, Mark A1 - Howat, Ian A1 - Langen, Peter L. A1 - Mortensen, John A1 - Lennert, Kunuk A1 - Rysgaard, Søren KW - glacier calving KW - glacier discharge KW - glacier mass balance KW - ice/atmosphere interactions KW - ice/ocean interactions KW - tidewater glaciers AB - We assess ice loss and velocity changes between 1985 and 2014 of three tidewater and five-land terminating glaciers in Godth{\aa}bsfjord (Nuup Kangerlua), Greenland. Glacier thinning accounted for 43.8 ± 0.2 km 3 of ice loss, equivalent to 0.10 mm eustatic sea-level rise. An additional 3.5 ± 0.3 km 3 was lost to the calving retreats of Kangiata Nunaata Sermia (KNS) and Narsap Sermia (NS), two tidewater glaciers that exhibited asynchronous behavior over the study period. KNS has retreated 22 km from its Little Ice Age (LIA) maximum (1761 AD), of which 0.8 km since 1985. KNS has stabilized in shallow water, but seasonally advects a 2 km long floating tongue. In contrast, NS began retreating from its LIA moraine in 2004–06 (0.6 km), re-stabilized, then retreated 3.3 km during 2010–14 into an over-deepened basin. Velocities at KNS ranged 5–6 km a −1 , while at NS they increased from 1.5 to 5.5 km a −1 between 2004 and 2014. We present comprehensive analyses of glacier thinning, runoff, surface mass balance, ocean conditions, submarine melting, bed topography, ice mélange and conclude that the 2010–14 NS retreat was triggered by a combination of factors but primarily by an increase in submarine melting. VL - 63 ER - TY - JOUR T1 - Diagnosing the decline in climatic mass balance of glaciers in Svalbard over 1957–2014 JF - The Cryosphere Y1 - 2017 A1 - Østby, T. I. A1 - Schuler, T. V. A1 - Hagen, J. O. A1 - Hock, R. A1 - Kohler, J. A1 - Reijmer, C. H. VL - 11 UR - https://www.the-cryosphere.net/11/191/2017/ ER - TY - JOUR T1 - Error sources in basal yield stress inversions for Jakobshavn Isbræ, Greenland, derived from residual patterns of misfit to observations JF - Journal of Glaciology Y1 - 2017 A1 - Habermann, Marijke A1 - Truffer, Martin A1 - Maxwell, David KW - glacier modeling KW - ice-sheet modeling KW - subglacial processes AB - The basal interface of glaciers is generally not directly observable. Geophysical inverse methods are therefore used to infer basal parameters from surface observations. Such methods can also provide information about potential inadequacies of the forward model. Ideally an inverse problem can be regularized so that the differences between modeled and observed surface velocities reflect observational errors. However, deficiencies in the forward model usually result in additional errors. Here we use the spatial pattern of velocity residuals to discuss the main error sources for basal stress inversions for Jakobshavn Isbræ, Greenland. Synthetic tests with prescribed patterns of basal yield stress with varying length scales are then used to investigate different weighting functions for the data-model misfit and for the ability of the inversion to resolve details in basal yield stress. We also test real-data inversions for their sensitivities to prior estimate, forward model parameters, data gaps, and temperature fields. We find that velocity errors are not sufficient to explain the residual patterns of real-data inversions. Conversely, ice-geometry errors and especially simulated errors in model simplifications are capable of reproducing similar error patterns and magnitudes. We suggest that residual patterns can provide useful guidance for forward model improvements. VL - 63 UR - https://www.cambridge.org/core/product/identifier/S0022143017000612/type/journal{\_}article ER - TY - JOUR T1 - Glacier Changes in the Susitna Basin, Alaska, USA,(1951–2015) using GIS and Remote Sensing Methods JF - Remote Sensing Y1 - 2017 A1 - Wastlhuber, Roland A1 - Hock, Regine A1 - Kienholz, Christian A1 - Braun, Matthias VL - 9 ER - TY - JOUR T1 - Grand Challenges in Cryospheric Sciences: Toward Better Predictability of Glaciers, Snow and Sea Ice JF - Frontiers in Earth Science Y1 - 2017 A1 - Hock, Regine A1 - Hutchings, Jennifer K. A1 - Lehning, Michael VL - 5 UR - http://journal.frontiersin.org/article/10.3389/feart.2017.00064 ER - TY - JOUR T1 - Hypsometric control on glacier mass balance sensitivity in Alaska and northwest Canada JF - Earth's Future Y1 - 2017 A1 - McGrath, D. A1 - Sass, L. A1 - O'Neel, S. A1 - Arendt, A. A1 - Kienholz, C. KW - Distribution KW - glaciers KW - hypsometry KW - mass balance KW - Modeling KW - modelling UR - http://dx.doi.org/10.1002/2016EF000479 ER - TY - JOUR T1 - Mass Balance Evolution of Black Rapids Glacier, Alaska, 1980–2100, and Its Implications for Surge Recurrence JF - Frontiers in Earth Science Y1 - 2017 A1 - Kienholz, Christian A1 - Hock, Regine A1 - Truffer, Martin A1 - Bieniek, Peter A1 - Lader, Richard AB - Surge-type Black Rapids Glacier, Alaska, has undergone strong retreat since it last surged in 1936-37. To assess its evolution during the late 20th and 21st centuries and determine potential implications for surge likelihood, we run a simplified glacier model over the periods 1980-2015 (hindcasting) and 2015-2100 (forecasting). The model is forced by daily temperature and precipitation fields, with downscaled reanalysis data used for the hindcasting. A constant climate scenario and an RCP 8.5 scenario based on the GFDL-CM3 climate model are employed for the forecasting. Debris evolution is accounted for by a debris layer time series derived from satellite imagery (hindcasting) and a parametrized debris evolution model (forecasting). A retreat model accounts for the evolution of the glacier geometry. Model calibration, validation and parametrization rely on an extensive set of in situ and remotely sensed observations. To explore uncertainties in our projections, we run the glacier model in a Monte Carlo fashion, varying key model parameters and input data within plausible ranges. Our results for the hindcasting period indicate a negative mass balance trend, caused by atmospheric warming in the summer, precipitation decrease in the winter and surface elevation lowering (climate-elevation feedback), which exceed the moderating effects from increasing debris cover and glacier retreat. Without the 2002 rockslide deposits on Black Rapids' lower reaches, the mass balances would be more negative, by  20% between the 2003 and 2015 mass-balance years. Despite its retreat, Black Rapids Glacier is substantially out of balance with the current climate. By 2100,  8% of Black Rapids' 1980 area are projected to vanish under the constant climate scenario and  73% under the RCP 8.5 scenario. For both scenarios, the remaining glacier portions are out of balance, suggesting continued retreat after 2100. Due to mass starvation, a surge in the 21st century is unlikely. The projected retreat will affect the glacier's runoff and change the landscape in the Black Rapids area markedly. VL - 5 UR - http://journal.frontiersin.org/article/10.3389/feart.2017.00056 ER - TY - JOUR T1 - Sediment transport drives tidewater glacier periodicity Y1 - 2017 A1 - Brinkerhoff, Douglas A1 - Truffer, Martin A1 - Aschwanden, Andy AB - Most of Earth’s glaciers are retreating, but some tidewater glaciers are advancing despite increasing temperatures and contrary to their neighbors. This can be explained by the coupling of ice and sediment dynamics: a shoal forms at the glacier terminus, reducing ice discharge and causing advance towards an unstable configuration followed by abrupt retreat, in a process known as the tidewater glacier cycle. Here we use a numerical model calibrated with observations to show that interactions between ice flow, glacial erosion, and sediment transport drive these cycles, which occur independent of climate variations. Water availability controls cycle period and amplitude, and enhanced melt from future warming could trigger advance even in glaciers that are steady or retreating, complicating interpretations of glacier response to climate change. The resulting shifts in sediment and meltwater delivery from changes in glacier configuration may impact interpretations of marine sediments, fjord geochemistry, and marine ecosystems. VL - 8 SN - 2041-1723 UR - https://doi.org/10.1038/s41467-017-00095-5 IS - 1 JO - Nature Communications ER - TY - JOUR T1 - Sub-ice-shelf sediments record history of twentieth-century retreat of Pine Island Glacier JF - Nature Y1 - 2017 A1 - Smith, J. A. A1 - Andersen, T. J. A1 - Shortt, M. A1 - Gaffney, A. M. A1 - Truffer, Martin A1 - Stanton, T P A1 - Bindschadler, Robert A1 - Dutrieux, Pierre A1 - Jenkins, Adrian A1 - Hillenbrand, C.-D. A1 - Ehrmann, Werner A1 - Corr, H. F. J. A1 - Farley, N. A1 - Crowhurst, S. A1 - Vaughan, David G. KW - Antarctica KW - Pine Island glacier AB - The West Antarctic Ice Sheet is one of the largest potential sources of rising sea levels. Over the past 40 years, glaciers flowing into the Amundsen Sea sector of the ice sheet have thinned at an accelerating rate, and several numerical models suggest that unstable and irreversible retreat of the grounding line—which marks the boundary between grounded ice and floating ice shelf—is underway. Understanding this recent retreat requires a detailed knowledge of grounding-line history, but the locations of the grounding line before the advent of satellite monitoring in the 1990s are poorly dated. In particular, a history of grounding-line retreat is required to understand the relative roles of contemporaneous ocean-forced change and of ongoing glacier response to an earlier perturbation in driving ice-sheet loss. Here we show that the present thinning and retreat of Pine Island Glacier in West Antarctica is part of a climatically forced trend that was triggered in the 1940s. Our conclusions arise from analysis of sediment cores recovered beneath the floating Pine Island Glacier ice shelf, and constrain the date at which the grounding line retreated from a prominent seafloor ridge. We find that incursion of marine water beyond the crest of this ridge, forming an ocean cavity beneath the ice shelf, occurred in 1945 (±12 years); final ungrounding of the ice shelf from the ridge occurred in 1970 (±4 years). The initial opening of this ocean cavity followed a period of strong warming of West Antarctica, associated with El Niño activity. Thus our results suggest that, even when climate forcing weakened, ice-sheet retreat continued. VL - 541 UR - http://dx.doi.org/10.1038/nature20136{%}5Cnhttp://www.nature.com/doifinder/10.1038/nature20136 http://www.nature.com/articles/nature20136 ER - TY - JOUR T1 - Automated detection of unstable glacier flow and a spectrum of speedup behavior in the Alaska Range JF - Journal of Geophysical Research F: Earth Surface Y1 - 2016 A1 - Herreid, Sam A1 - Truffer, Martin KW - automated detection KW - debris cover KW - pulse-type glaciers KW - spectrum of glacier flow instabilities KW - surge-type glaciers VL - 121 ER - TY - JOUR T1 - Bayesian Inference of Subglacial Topography Using Mass Conservation JF - Frontiers in Earth Science Y1 - 2016 A1 - Brinkerhoff, Douglas J A1 - Aschwanden, Andy A1 - Truffer, Martin AB - We develop a Bayesian model for estimating ice thickness given sparse observations coupled with estimates of surface mass balance, surface elevation change, and surface velocity. These fields are related through mass conservation. We use the Metropolis-Hastings algorithm to sample from the posterior probability distribution of ice thickness for three cases: a synthetic mountain glacier, ̈ Storglaci aren, and Jakobshavn Isbræ. Use of continuity in interpolation improves thickness estimates where relative velocity and surface mass balance errors are small, a condition difficult to maintain in regions of slow flow and surface mass balance near zero. Estimates of thickness uncertainty depend sensitively on spatial correlation. When this structure is known, we suggest a thickness measurement spacing of one to two times the correlation length to take best advantage of continuity based interpolation techniques. To determine ideal measurement spacing, the structure of spatial correlation must be better quantified. VL - 4 UR - http://journal.frontiersin.org/article/10.3389/feart.2016.00008 ER - TY - JOUR T1 - Complex Greenland outlet glacier flow captured JF - Nature Communications Y1 - 2016 A1 - Aschwanden, Andy A1 - Fahnestock, Mark A A1 - Truffer, Martin VL - 7 UR - http://www.nature.com/doifinder/10.1038/ncomms10524 ER - TY - JOUR T1 - Geodetic mass balance of surge-type Black Rapids Glacier, Alaska, 1980–2001–2010, including role of rockslide deposition and earthquake displacement JF - Journal of Geophysical Research: Earth Surface Y1 - 2016 A1 - Kienholz, C A1 - Hock, R A1 - Truffer, M A1 - Arendt, A A1 - Arko, S ER - TY - JOUR T1 - Geodetic measurements reveal similarities between post-Last Glacial Maximum and present-day mass loss from the Greenland ice sheet JF - Science Advances Y1 - 2016 A1 - Khan, Shfaqat A A1 - Sasgen, Ingo A1 - Bevis, Michael A1 - van Dam, T. A1 - Bamber, Jonathan L A1 - Wahr, John A1 - Willis, Michael A1 - Kjaer, K. H. A1 - Wouters, Bert A1 - Helm, Veit A1 - Csatho, Beata A1 - Fleming, Kevin A1 - Bjork, A. A. A1 - Aschwanden, Andy A1 - Knudsen, Per A1 - Munneke, Peter Kuipers VL - 2 UR - http://advances.sciencemag.org/cgi/doi/10.1126/sciadv.1600931 ER - TY - JOUR T1 - Holocene deceleration of the Greenland Ice Sheet JF - Science Y1 - 2016 A1 - MacGregor, J. A. A1 - Colgan, W. T. A1 - Fahnestock, M. A. A1 - Morlighem, M. A1 - Catania, G. A. A1 - Paden, J. D. A1 - Gogineni, S. P. VL - 351 UR - http://www.sciencemag.org/cgi/doi/10.1126/science.aab1702 ER - TY - JOUR T1 - Inversion of a glacier hydrology model JF - Ann. Glaciol. Y1 - 2016 A1 - D. J. Brinkerhoff A1 - C. R. Meyer A1 - E. Bueler A1 - M. Truffer VL - 57 ER - TY - JOUR T1 - Modeling the evolution of the Juneau Icefield between 1971 and 2100 using the Parallel Ice Sheet Model (PISM) JF - Journal of Glaciology Y1 - 2016 A1 - Ziemen, Florian A A1 - Hock, Regine A1 - Aschwanden, Andy A1 - Khroulev, Constantine A1 - Kienholz, Christian A1 - MELKONIAN, ANDREW A1 - ZHANG, JING VL - 62 ER - TY - JOUR T1 - Modelled glacier dynamics over the last quarter of a century at Jakobshavn Isbræ JF - The Cryosphere Y1 - 2016 A1 - Muresan, Ioana S. A1 - Khan, Shfaqat A. A1 - Aschwanden, Andy A1 - Khroulev, Constantine A1 - Van Dam, Tonie A1 - Bamber, Jonathan A1 - van den Broeke, Michiel R. A1 - Wouters, Bert A1 - Kuipers Munneke, Peter A1 - Kjær, Kurt H. VL - 10 UR - http://www.the-cryosphere.net/10/597/2016/ ER - TY - JOUR T1 - Sensitivity of Pine Island Glacier to observed ocean forcing JF - Geophysical Research Letters Y1 - 2016 A1 - Christianson, Knut A1 - Bushuk, Mitchell A1 - Dutrieux, Pierre A1 - Parizek, Byron R. A1 - Joughin, Ian R. A1 - Alley, Richard B. A1 - Shean, David E. A1 - Abrahamsen, E. Povl A1 - Anandakrishnan, Sridhar A1 - Heywood, Karen J. A1 - Kim, Tae-Wan A1 - Lee, Sang Hoon A1 - Nicholls, Keith A1 - Stanton, Tim A1 - Truffer, Martin A1 - Webber, Benjamin G. M. A1 - Jenkins, Adrian A1 - Jacobs, Stan A1 - Bindschadler, Robert A1 - Holland, David M. KW - glacier-ocean interactions KW - Ice Dynamics KW - ice shelves KW - ice streams KW - marine ice sheet instability AB - ©2016. American Geophysical Union. All Rights Reserved.We present subannual observations (2009–2014) of a major West Antarctic glacier (Pine Island Glacier) and the neighboring ocean. Ongoing glacier retreat and accelerated ice flow were likely triggered a few decades ago by increased ocean-induced thinning, which may have initiated marine ice sheet instability. Following a subsequent 60{%} drop in ocean heat content from early 2012 to late 2013, ice flow slowed, but by {\textless} 4{%}, with flow recovering as the ocean warmed to prior temperatures. During this cold-ocean period, the evolving glacier-bed/ice shelf system was also in a geometry favorable to stabilization. However, despite a minor, temporary decrease in ice discharge, the basin-wide thinning signal did not change. Thus, as predicted by theory, once marine ice sheet instability is underway, a single transient high-amplitude ocean cooling has only a relatively minor effect on ice flow. The long-term effects of ocean temperature variability on ice flow, however, are not yet known. VL - 43 UR - http://doi.wiley.com/10.1002/2016GL070500 ER - TY - JOUR T1 - Stable finite volume element schemes for the shallow ice approximation JF - Journal of Glaciology Y1 - 2016 A1 - E. Bueler VL - 62 ER - TY - JOUR T1 - A synthesis of the basal thermal state of the Greenland Ice Sheet JF - Journal of Geophysical Research: Earth Surface Y1 - 2016 A1 - MacGregor, Joseph A. A1 - Fahnestock, Mark A. A1 - Catania, Ginny A. A1 - Aschwanden, Andy A1 - Clow, Gary D. A1 - Colgan, William T. A1 - Gogineni, S. Prasad A1 - Morlighem, Mathieu A1 - Nowicki, Sophie M. J. A1 - Paden, John D. A1 - Price, Stephen F. A1 - Seroussi, Helene UR - http://doi.wiley.com/10.1002/2015JF003803 ER - TY - JOUR T1 - The taphonomy of human remains in a glacial environment JF - Forensic Science International Y1 - 2016 A1 - Pilloud, Marin A. A1 - Megyesi, Mary S. A1 - Truffer, Martin A1 - Congram, Derek KW - Forensic anthropology KW - Glacial dynamics KW - Glacial movement KW - Glacial taphonomy AB - A glacial environment is a unique setting that can alter human remains in characteristic ways. This study describes glacial dynamics and how glaciers can be understood as taphonomic agents. Using a case study of human remains recovered from Colony Glacier, Alaska, a glacial taphonomic signature is outlined that includes: (1) movement of remains, (2) dispersal of remains, (3) altered bone margins, (4) splitting of skeletal elements, and (5) extensive soft tissue preservation and adipocere formation. As global glacier area is declining in the current climate, there is the potential for more materials of archaeological and medicolegal significance to be exposed. It is therefore important for the forensic anthropologist to have an idea of the taphonomy in this setting and to be able to differentiate glacial effects from other taphonomic agents. VL - 261 UR - http://dx.doi.org/10.1016/j.forsciint.2016.01.027 ER - TY - JOUR T1 - Where Glaciers Meet Water: Subaqueous Melt and its Relevance to Glaciers in Various Settings JF - Reviews of Geophysics Y1 - 2016 A1 - Truffer, M. A1 - Motyka, Roman KW - 10.1002/2015RG000494 and glaciers KW - calving KW - melt KW - ocean UR - http://doi.wiley.com/10.1002/2015RG000494 ER - TY - JOUR T1 - Derivation and analysis of a complete modern-date glacier inventory for Alaska and northwest Canada JF - Journal of Glaciology Y1 - 2015 A1 - Kienholz, Christian A1 - Herreid, Sam A1 - Rich, J A1 - Arendt, A A1 - Hock, R A1 - Burgess, E VL - 61 ER - TY - JOUR T1 - Dynamic jamming of iceberg-choked fjords JF - Geophys. Res. Lett. Y1 - 2015 A1 - Peters, I A1 - Amundson, J. M. A1 - Cassotto, R A1 - Fahnestock, M A1 - Darnell, K A1 - Truffer, M. A1 - Zhang, W. KW - 10.1002/2014GL062715 and glaciers KW - calving KW - icebergs KW - jamming VL - 42 ER - TY - JOUR T1 - End-of-winter snow depth variability on glaciers in Alaska JF - Journal of Geophysical Research: Earth Surface Y1 - 2015 A1 - McGrath, Daniel A1 - Sass, Louis A1 - O'Neel, Shad A1 - Arendt, Anthony A1 - Wolken, Gabriel A1 - Gusmeroli, Alessio A1 - Kienholz, Christian A1 - McNeil, Christopher VL - 120 ER - TY - JOUR T1 - Greenland ice sheet mass balance JF - Reports on Progress in Physics Y1 - 2015 A1 - Khan, Shfaqat A. A1 - Aschwanden, Andy A1 - Bjørk, Anders A A1 - Whar, John A1 - Kjeldsen, Kristian K. A1 - Kjær, Kurt H. AB - Mass balance equation for glaciers; areal distribution and ice volumes; estimates of actual mass balance; loss by calving of icebergs; hydrological budget for Greenland; and temporal variations of Greenland mass balance are examined. PB - IOP Publishing VL - 78 UR - http://dx.doi.org/10.1088/0034-4885/78/4/046801 ER - TY - JOUR T1 - Mapping snow depth from manned aircraft on landscape scales at centimeter resolution using structure-from-motion photogrammetry JF - The Cryosphere Y1 - 2015 A1 - Nolan, M. A1 - Larsen, C. F. A1 - Sturm, M. VL - 9 UR - http://www.the-cryosphere.net/9/1445/2015/ ER - TY - JOUR T1 - Mass-conserving subglacial hydrology in the Parallel Ice Sheet Model version 0.6 JF - Geoscientific Model Development Y1 - 2015 A1 - E. Bueler A1 - van Pelt, W. VL - 8 UR - http://www.geosci-model-dev.net/8/1613/2015/ ER - TY - JOUR T1 - A new model for global glacier change and sea-level rise JF - Frontiers in Earth Science Y1 - 2015 A1 - Huss, Matthias A1 - Hock, Regine AB - The anticipated retreat of glaciers around the globe will pose far-reaching challenges to the management of fresh water resources and significantly contribute to sea-level rise within the coming decades. Here, we present a new model for calculating the 21st century mass changes of all glaciers on Earth outside the ice sheets. The Global Glacier Evolution Model (GloGEM) includes mass loss due to frontal ablation at marine-terminating glacier fronts and accounts for glacier advance/retreat and surface Elevation changes. Simulations are driven with monthly near-surface air temperature and precipitation from 14 Global Circulation Models forced by the RCP2.6, RCP4.5 and RCP8.5 emission scenarios. Depending on the scenario, the model yields a global glacier volume loss of 25-48% between 2010 and 2100. For calculating glacier contribution to sea-level rise, we account for ice located below sea-level presently displacing ocean water. This effect reduces glacier contribution by 11-14%, so that our model predicts a sea-level equivalent (multi-model mean +-1 standard deviation) of 79+-24 mm (RCP2.6), 108+-28 mm (RCP4.5) and 157+-31 mm (RCP8.5). Mass losses by frontal ablation account for 10% of total ablation globally, and up to 30% regionally. Regional equilibrium line altitudes are projected to rise by 100-800 m until 2100, but the effect on ice wastage depends on initial glacier hypsometries. VL - 3 UR - http://journal.frontiersin.org/article/10.3389/feart.2015.00054 ER - TY - JOUR T1 - Radar attenuation and temperature within the Greenland Ice Sheet JF - Journal of Geophysical Research: Earth Surface Y1 - 2015 A1 - MacGregor, Joseph A. A1 - Li, Jilu A1 - Paden, John D A1 - Catania, Ginny a A1 - Clow, Gary D A1 - Fahnestock, Mark A A1 - Gogineni, S Prasad A1 - Grimm, Robert E A1 - Morlighem, Mathieu A1 - Nandi, Soumyaroop A1 - Seroussi, Helene A1 - Stillman, David E VL - 120 UR - http://doi.wiley.com/10.1002/2014JF003418 ER - TY - JOUR T1 - Radiostratigraphy and age structure of the Greenland Ice Sheet JF - Journal of Geophysical Research: Earth Surface Y1 - 2015 A1 - MacGregor, Joseph A. A1 - Fahnestock, Mark A. A1 - Catania, Ginny A. A1 - Paden, John D A1 - Prasad Gogineni, S. A1 - Young, S Keith A1 - Rybarski, Susan C A1 - Mabrey, Alexandria N A1 - Wagman, Benjamin M A1 - Morlighem, Mathieu KW - 10.1002/2014JF003215 and Greenland Ice Sheet KW - ice core KW - ice-penetrating dynamics KW - ice-sheet dynamics VL - 120 UR - http://doi.wiley.com/10.1002/2014JF003215 ER - TY - JOUR T1 - Rapid large-area mapping of ice flow using Landsat 8 JF - Remote Sensing of Environment Y1 - 2015 A1 - Fahnestock, Mark A1 - Scambos, Ted A1 - Moon, Twila A1 - Gardner, Alex A1 - Haran, Terry A1 - Klinger, Marin KW - Antarctica KW - glaciers KW - Greenland KW - Ice flow KW - Landsat KW - Remote sensing AB - We report on the maturation of optical satellite-image-based ice velocity mapping over the ice sheets and large glacierized areas, enabled by the high radiometric resolution and internal geometric accuracy of Landsat 8's Operational Land Imager (OLI). Detailed large-area single-season mosaics and time-series maps of ice flow were created using data spanning June 2013 to June 2015. The 12-bit radiometric quantization and 15-m pixel scale resolution of OLI band 8 enable displacement tracking of subtle snow-drift patterns on ice sheet surfaces at $\sim$. 1. m precision. Ice sheet and snowfield snow-drift features persist for typically 16 to 64. days, and up to 432. days, depending primarily on snow accumulation rates. This results in spatially continuous mapping of ice flow, extending the mapping capability beyond crevassed areas. Our method uses image chip cross-correlation and sub-pixel peak-fitting in matching Landsat path/row pairs. High-pass filtering is applied to the imagery to enhance local surface texture. The current high image acquisition rates of Landsat 8 (725 scenes per day globally) reduces the impact of high cloudiness in polar and mountain terrain and allows rapid compilation of large areas, or dense temporal coverage of seasonal ice flow variations. The results rival the coverage and accuracy of interferometric Synthetic Aperture Radar (InSAR) mapping. PB - The Authors UR - http://dx.doi.org/10.1016/j.rse.2015.11.023 ER - TY - JOUR T1 - Recent Arctic tundra fire initiates widespread thermokarst development JF - Scientific Reports Y1 - 2015 A1 - Jones, Benjamin M. A1 - Grosse, Guido A1 - Arp, Christopher D. A1 - Miller, Eric A1 - Liu, Lin A1 - Hayes, Daniel J. A1 - Larsen, Christopher F. VL - 5 UR - http://dx.doi.org/10.1038/srep15865 ER - TY - JOUR T1 - The response of fabric variations to simple shear and migration recrystallization JF - Journal of Glaciology Y1 - 2015 A1 - Kennedy, Joseph H. A1 - Pettit, Erin C. AB - The observable microstructures in ice are the result of many dynamic and competing processes. These processes are influenced by climate variables in the firn. Layers deposited in different climate regimes may show variations in fabric which can persist deep into the ice sheet; fabric may ‘remember’ these past climate regimes. We model the evolution of fabric variations below the firn–ice transition and show that the addition of shear to compressive-stress regimes preserves the modeled fabric variations longer than compression-only regimes, because shear drives a positive feedback between crystal rotation and deformation. Even without shear, the modeled ice retains memory of the fabric variation for ~200 ka in typical polar ice-sheet conditions. Our model shows that temperature affects how long the fabric variation is preserved, but only affects the strain-integrated fabric evolution profile when comparing results straddling the thermal-activation-energy threshold (~–10°C). Even at high temperatures, migration recrystallization does not eliminate the modeled fabric’s memory under most conditions. High levels of nearest-neighbor interactions will, however, eliminate the modeled fabric’s memory more quickly than low levels of nearest-neighbor interactions. Ultimately, our model predicts that fabrics will retain memory of past climatic variations when subject to a wide variety of conditions found in polar ice sheets. VL - 61 UR - http://openurl.ingenta.com/content/xref?genre=article&issn=0022-1430&volume=61&issue=227&spage=537http://www.ingentaconnect.com/content/igsoc/jog/2015/00000061/00000227/art00011 IS - 227 JO - Journal of Glaciology ER - TY - JOUR T1 - Run-away thinning of the low elevation Yakutat Glacier and its sensitivity to climate change JF - Journal of Glaciology Y1 - 2015 A1 - Truessel, Barbara A1 - Martin Truffer A1 - Regine Hock A1 - Roman Motyka A1 - Matthias Huss A1 - Jing Zhang VL - 61 ER - TY - JOUR T1 - Satellite observations show no net change in the percentage of supraglacial debris-covered area in northern Pakistan from 1977 to 2014 JF - Journal of Glaciology Y1 - 2015 A1 - Herreid, Sam A1 - Pellicciotti, Francesca A1 - Ayala, Alvaro A1 - Chesnokova, Anna A1 - Kienholz, Christian A1 - Shea, Joseph A1 - Shrestha, Arun VL - 61 ER - TY - JOUR T1 - Seasonal and interannual variations in ice melange and its impact on terminus stability, Jakobshavn Isbræ, Greenland JF - Journal of Glaciology Y1 - 2015 A1 - Cassotto, Ryan A1 - Fahnestock, Mark A1 - Amundson, Jason M. A1 - Truffer, Martin A1 - Joughin, Ian KW - arctic glaciology KW - calving KW - ice KW - ocean interactions KW - Remote sensing KW - sea-ice dynamics VL - 61 ER - TY - JOUR T1 - Subglacial discharge at tidewater glaciers revealed by seismic tremor JF - Geophysical Research Letters Y1 - 2015 A1 - Bartholomaus, Timothy C A1 - Amundson, Jason M A1 - Walter, Jacob I A1 - O'Neel, Shad A1 - West, Michael E A1 - Chris F. Larsen ER - TY - JOUR T1 - Surface melt dominates Alaska glacier mass balance JF - Geophysical Research Letters Y1 - 2015 A1 - Chris F. Larsen A1 - Burgess, E A1 - Arendt, AA A1 - O'Neel, S A1 - Johnson, AJ A1 - Kienholz, C VL - 42 ER - TY - JOUR T1 - Tidal and seasonal variations in calving flux observed with passive seismology JF - Journal of Geophysical Research: Earth Surface Y1 - 2015 A1 - Bartholomaus, Timothy C A1 - Larsen, Christopher F A1 - West, Michael E A1 - O'Neel, Shad A1 - Pettit, Erin C A1 - Truffer, Martin ER - TY - JOUR T1 - Triggered Seismic Events along the Eastern Denali Fault in Northwest Canada Following the 2012 Mw 7.8 Haida Gwaii, 2013 Mw 7.5 Craig, and Two Mw>8.5 Teleseismic Earthquakes JF - Bulletin of the Seismological Society of America Y1 - 2015 A1 - Chastity Aiken A1 - Jessica Zimmerman Mejia AB - We conduct a systematic search for remotely triggered seismic activity along the eastern Denali fault (EDF) in northwest Canada, an intraplate strike‐slip region. We examine 19 distant earthquakes recorded by nine broadband stations in the Canadian National Seismograph Network and find that the 2012 Mw 7.8 Haida Gwaii and 2013 Mw 7.5 Craig, Alaska, earthquakes triggered long duration (>10  s), emergent tremor‐like signals near the southeastern portion of the EDF. In both cases, tremor coincides with the peak transverse velocities, consistent with Love‐wave triggering on right‐lateral strike‐slip faults. The 2011 Mw 9.0 Tohoku‐Oki and 2012 Mw 8.6 Indian Ocean earthquakes possibly triggered tremor signals, although we were unable to locate those sources. In addition, we also identify many short‐duration (<5  s) bursts that were repeatedly triggered by the Rayleigh waves of the 2012 Mw 7.8 Haida Gwaii earthquake. Although we were unable to precisely locate the short‐duration (<5  s) events, they appear to be radiating from the direction of the Klutlan Glacier and from a belt of shallow historical seismicity at the eastern flank of the Wrangell–St. Elias mountain range. The fact that these events were triggered solely by the Rayleigh waves suggests a different source mechanism as compared with triggered tremor observed along the EDF and other plate boundary regions. VL - 105 UR - http://www.bssaonline.org/content/early/2015/04/08/0120140156.abstract IS - 2B ER - TY - JOUR T1 - Variations in Alaska tidewater glacier frontal ablation, 1985–2013 JF - Journal of Geophysical Research: Earth Surface Y1 - 2015 A1 - McNabb, R. W. A1 - Hock, R. A1 - Huss, M. KW - frontal ablation KW - glacier dynamics KW - glaciers KW - ice thickness VL - 120 UR - http://dx.doi.org/10.1002/2014JF003276 ER - TY - JOUR T1 - 21st-century increase in glacier mass loss in the Wrangell Mountains, Alaska, USA, from airborne laser altimetry and satellite stereo imagery JF - J. Glaciol. Y1 - 2014 A1 - Das, Indrani A1 - Hock, Regine A1 - Berthier, Etienne A1 - Lingle, Craig S. KW - glacier mass balance KW - ice and climate VL - 60 UR - http://www.igsoc.org/journal/60/220/j13J119.html ER - TY - JOUR T1 - Alaska National Park glaciers: what do they tell us about climate change? JF - Alaska Park Science Y1 - 2014 A1 - Loso, M.G. A1 - Arendt, A. A1 - Chris F. Larsen A1 - Murphy, N. A1 - Rich, J. VL - 12 ER - TY - JOUR T1 - Alaska tidewater glacier terminus positions, 1948-2012 JF - Journal of Geophysical Research: Earth Surface Y1 - 2014 A1 - R  W McNabb A1 - Hock, R. VL - 119 UR - http://doi.wiley.com/10.1002/jgrf.v119.2http://doi.wiley.com/10.1002/2013JF002915 IS - 2 JO - J. Geophys. Res. Earth Surf. ER - TY - JOUR T1 - Boundary condition of grounding lines prior to collapse, Larsen-B Ice Shelf, Antarctica JF - Science Y1 - 2014 A1 - Rebesco, M A1 - Domack, E A1 - Zgur, F A1 - Lavoie, C A1 - Leventer, A A1 - Brachfeld, S A1 - Willmott, V A1 - Halverson, G A1 - Truffer, M A1 - Scambos, T A1 - Pettit, Erin C PB - American Association for the Advancement of Science VL - 345 ER - TY - JOUR T1 - Correspondence: Extending the lumped subglacial–englacial hydrology model of Bartholomaus and others (2011) JF - J. Glaciol. Y1 - 2014 A1 - E. Bueler VL - 60 UR - http://www.igsoc.org/journal/60/222/t14j075.html ER - TY - JOUR T1 - Coupled ice sheet–climate modeling under glacial and pre-industrial boundary conditions JF - Climate of the Past Y1 - 2014 A1 - Ziemen, F. A. A1 - Rodehacke, C. B. A1 - Mikolajewicz, U. AB - In the standard Paleoclimate Modelling Intercomparison Project (PMIP) experiments, the Last Glacial Maximum (LGM) is modeled in quasi-equilibrium with atmosphere–ocean–vegetation general circulation models (AOVGCMs) with prescribed ice sheets. This can lead to inconsistencies between the modeled climate and ice sheets. One way to avoid this problem would be to model the ice sheets explicitly. Here, we present the first results from coupled ice sheet–climate simulations for the pre-industrial times and the LGM. Our setup consists of the AOVGCM ECHAM5/MPIOM/LPJ bidirectionally coupled with the Parallel Ice Sheet Model (PISM) covering the Northern Hemisphere. The results of the pre-industrial and LGM simulations agree reasonably well with reconstructions and observations. This shows that the model system adequately represents large, non-linear climate perturbations. A large part of the drainage of the ice sheets occurs in ice streams. Most modeled ice stream systems show recurring surges as internal oscillations. The Hudson Strait Ice Stream surges with an ice volume equivalent to about 5 m sea level and a recurrence interval of about 7000 yr. This is in agreement with basic expectations for Heinrich events. Under LGM boundary conditions, different ice sheet configurations imply different locations of deep water formation. VL - 10 UR - http://www.clim-past.net/10/1817/2014/cp-10-1817-2014.html ER - TY - JOUR T1 - The effect of climate forcing on numerical simulations of the Cordilleran ice sheet at the Last Glacial Maximum JF - The Cryosphere Y1 - 2014 A1 - Seguinot, J. A1 - Khroulev, C. A1 - Rogozhina, I. A1 - Stroeven, A. P. A1 - Zhang, Q. VL - 8 UR - http://www.the-cryosphere.net/8/1087/2014/ ER - TY - JOUR T1 - An exact solution for a steady, flow-line marine ice sheet JF - J. Glaciol. Y1 - 2014 A1 - E. Bueler VL - 60 ER - TY - JOUR T1 - Glacier area and length changes in Norway from repeat inventories JF - The Cryosphere Y1 - 2014 A1 - Winsvold, S. H. A1 - Andreassen, L. M. A1 - Kienholz, C. VL - 8 ER - TY - JOUR T1 - Glacier changes in the Karakoram region mapped by multimission satellite imagery JF - The Cryosphere Y1 - 2014 A1 - Rankl, Melanie A1 - Kienholz, C A1 - Braun, M VL - 8 ER - TY - JOUR T1 - Glacier dynamics at Helheim and Kangerdlugssuaq glaciers, southeast Greenland, since the Little Ice Age JF - The Cryosphere Y1 - 2014 A1 - Khan, S. A. A1 - Kjeldsen, K. K. A1 - Kjær, K. H. A1 - Bevan, S. A1 - Luckman, A. A1 - Aschwanden, A. A1 - Bjørk, A. A. A1 - Korsgaard, N. J. A1 - Box, J. E. A1 - Van Den Broeke, M. A1 - van Dam, T. M. A1 - Fitzner, A. VL - 8 UR - http://www.the-cryosphere.net/8/1497/2014/ ER - TY - CHAP T1 - Glacier Surges T2 - Snow and Ice-Related Hazards, Risks, and Disasters Y1 - 2014 A1 - Harrison, W.D. A1 - Osipova, G.B. A1 - Nosenko, G.A. A1 - Espizua, L. A1 - Kääb, A. A1 - L Fischer  A1 - Huggel, C. A1 - Craw Burns, P.A. A1 - Truffer, M. A1 - Lai, A.W. KW - Flow instabilities KW - Ice dammed lakes KW - Outburst floods KW - Pipeline safety KW - River blocking KW - surge-type glaciers AB - © 2015 Elsevier Inc. All rights reserved.Surge-type glaciers periodically undergo large flow acceleration after extended quiescent phases of slow movement, usually accompanied by terminus advance. Such glaciers are relatively rare but occur in many of the world's glacierized areas. High water pressures and extreme basal sliding are obvious characteristics but key questions concerning this, usually spectacular phenomenon, remain open. Why are glaciers in some regions surge-type but not in others, what sort of "memory" lets glaciers surge again and again, what is the influence of climate, geology, and topography? Besides their scientific interest, glacier surges can also be a threat to humans, especially in connection with rapidly forming lakes and their sudden outbursts. Cases of hazard- and disaster-related glacier surges are described from the Pamirs, the Andes, the Italian Alps, and Alaska. JF - Snow and Ice-Related Hazards, Risks, and Disasters SN - 9780123964731 ER - TY - CHAP T1 - Glaciers and Climate Change T2 - Handbook of Global Environmental Pollution: Global Environmental Change Y1 - 2014 A1 - Regine Hock ED - B. Freedman JF - Handbook of Global Environmental Pollution: Global Environmental Change PB - Springer ER - TY - JOUR T1 - Glaciers in the Earth’s Hydrological Cycle: Assessments of Glacier Mass and Runoff Changes on Global and Regional Scales JF - Surveys in Geophysics Y1 - 2014 A1 - Radić, Valentina A1 - Hock, Regine KW - Glacier projections KW - glacier runoff KW - glaciers KW - mass balance KW - Mass-balance observations KW - Modeling KW - Sea-level rise VL - 35 UR - http://dx.doi.org/10.1007/s10712-013-9262-y ER - TY - JOUR T1 - Global response of glacier runoff to twenty-first century climate change JF - Journal of Geophysical Research: Earth Surface Y1 - 2014 A1 - Bliss, Andrew A1 - Hock, Regine A1 - Radić, Valentina KW - climate change KW - glacier mass balance KW - glacier runoff VL - 119 UR - http://dx.doi.org/10.1002/2013JF002931 ER - TY - JOUR T1 - Helicopter borne radar imaging of snow cover on and around glaciers in Alaska JF - Annals of Glaciology Y1 - 2014 A1 - Gusmeroli, A. A1 - Wolken, G. A1 - Arendt, A. VL - 55 ER - TY - RPRT T1 - Ice Thickness Measurements on the Harding Icefield , Kenai Peninsula , Alaska Y1 - 2014 A1 - Truffer, Martin ER - TY - JOUR T1 - Influence of debris-rich basal ice on flow of a polar glacier JF - Journal of Glaciology Y1 - 2014 A1 - Pettit, Erin C A1 - Whorton, Erin N A1 - Waddington, Edwin D A1 - Sletten, Ronald S PB - International Glaciological Society VL - 60 ER - TY - JOUR T1 - A new method for deriving glacier centerlines applied to glaciers in Alaska and northwest Canada JF - The Cryosphere Y1 - 2014 A1 - Kienholz, C. A1 - Rich, J. L. A1 - Arendt, A. A. A1 - Hock, R. VL - 8 UR - http://www.the-cryosphere.net/8/503/2014/ ER - TY - JOUR T1 - Quantifying velocity response to ocean tides and calving near the terminus of Jakobshavn Isbræ, Greenland JF - Journal of Glaciology Y1 - 2014 A1 - Podrasky, David A1 - Truffer, Martin A1 - Lüthi, Martin A1 - Fahnestock, Mark KW - calving KW - glacier fluctuations KW - ice KW - ocean interactions VL - 60 UR - http://www.igsoc.org/journal/60/222/t13J130.html ER - TY - JOUR T1 - The Randolph Glacier Inventory: a globally complete inventory of glaciers Y1 - 2014 A1 - Pfeffer, W.T. A1 - Arendt, A. A1 - Bliss, A. A1 - Bolch, T. A1 - Cogley, G. A1 - Gardner, A. A1 - Hagen, J-O., A1 - Hock, R. A1 - Kaser, G A1 - Kienholz, C. A1 - Miles, E. A1 - Moholdt, G. A1 - Mölg, N. A1 - Paul, F. A1 - Radić, V. A1 - Rastner, P. A1 - Raup, B. A1 - Rich, J. A1 - Sharp, M. VL - 60 ER - TY - JOUR T1 - Resolution-dependent performance of grounding line motion in a shallow model compared to a full-Stokes model according to the MISMIP3d intercomparison JF - J. Glaciol. Y1 - 2014 A1 - Feldmann, J. A1 - Albrecht, T. A1 - Khroulev, C. A1 - Pattyn, F. A1 - Levermann, A. VL - 60 ER - TY - JOUR T1 - Role of model initialization for projections of 21st-century Greenland ice sheet mass loss JF - Journal of Glaciology Y1 - 2014 A1 - Aðalgeirsdóttir, Guðfinna A1 - Aschwanden, Andy A1 - Khroulev, Constantine A1 - Boberg, Frederik A1 - Mottram, Ruth A1 - Lucas-Picher, P. KW - ice and climate KW - ice-sheet modeling VL - 60 UR - http://www.igsoc.org/journal/60/222/t13j202.html ER - TY - JOUR T1 - Surface Drifters Track the Fate of Greenland Ice Sheet Meltwater JF - Eos Trans. AGU Y1 - 2014 A1 - Hauri, C. A1 - Truffer, M. A1 - Winsor, P. A1 - Lennert, K. VL - 95 ER - TY - JOUR T1 - Surface velocity and mass balance of Livingston Island ice cap, Antarctica JF - The Cryosphere Y1 - 2014 A1 - Osmanoglu, B. A1 - Navarro, F. J. A1 - Hock, R. A1 - Braun, M. A1 - Corcuera, M. I. VL - 8 UR - http://www.the-cryosphere.net/8/1807/2014/ ER - TY - JOUR T1 - A system of conservative regridding for ice–atmosphere coupling in a General Circulation Model (GCM) JF - Geoscientific Model Development Y1 - 2014 A1 - Fischer, R. A1 - Nowicki, S. A1 - Kelley, M. A1 - Schmidt, G. A. KW - 1911-UW KW - Regridding AB - The method of elevation classes, in which the ice surface model is run at multiple elevations within each grid cell, has proven to be a useful way for a low-resolution atmosphere inside a general circulation model (GCM) to produce high-resolution downscaled surface mass balance fields for use in one-way studies coupling atmospheres and ice flow models. Past uses of elevation classes have failed to conserve mass and energy because the transformation used to regrid to the atmosphere was inconsistent with the transformation used to downscale to the ice model. This would cause problems for two-way coupling. VL - 7 UR - https://www.geosci-model-dev.net/7/883/2014/ ER - TY - JOUR T1 - Variations in Alaska tidewater glacier frontal ablation, 1985–2013 JF - Journal of Geophysical Research: Earth Surface Y1 - 2014 A1 - McNabb, R. W. A1 - Hock, R. A1 - Huss, M. KW - frontal ablation KW - glacier dynamics KW - ice thickness UR - http://dx.doi.org/10.1002/2014JF003276 ER - TY - JOUR T1 - Active tectonics of the St. Elias orogen, Alaska, observed with GPS measurements JF - Journal of Geophysical Research: Solid Earth Y1 - 2013 A1 - Elliott, Julie A1 - Jeffrey T. Freymueller A1 - Chris F. Larsen KW - Alaska KW - geodesy KW - St. Elias orogen KW - tectonics KW - Yakutat block AB - We use data from campaign and continuous GPS sites in southeast and south central Alaska to constrain a regional tectonic block model for the St. Elias orogen. Active tectonic deformation in the orogen is dominated by the effects of the collision of the Yakutat block with southern Alaska. Our results indicate that  37 mm/yr of convergence is accommodated along a relatively narrow belt of N-NW dipping thrust faults in the eastern half of the orogen, with the present-day deformation front running through Icy Bay and beneath the Malaspina Glacier. Near the Bering Glacier, the collisional thrust fault regime transitions into a broad, northwest dipping décollement as the Yakutat block basement begins to subduct beneath the counterclockwise rotating Elias block. The location of this transition aligns with the Gulf of Alaska shear zone, implying that the Pacific plate is fragmenting in response to the Yakutat collision. Our model indicates that the Bering Glacier region is undergoing internal deformation and could correspond to the final stage of offscraping and accretion of sediments from the Yakutat block prior to subduction. Predicted block motions at the western edge of the orogen suggest that the crust is laterally escaping along the Aleutian fore arc. UR - http://dx.doi.org/10.1002/jgrb.50341 ER - TY - JOUR T1 - Analysis of a GRACE global mascon solution for Gulf of Alaska glaciers JF - Journal of Glaciology Y1 - 2013 A1 - Anthony A. Arendt A1 - Scott B Luthcke A1 - Alex S. Gardner A1 - Shad OʼNeel A1 - D. Hill A1 - Geir Moholdt A1 - Waleed Abdalati VL - 59 IS - 217 ER - TY - JOUR T1 - Antarctica, Greenland and Gulf of Alaska land-ice evolution from an iterated GRACE global mascon solution JF - Journal of Glaciology Y1 - 2013 A1 - Scott B Luthcke A1 - Sabaka, TJ A1 - Loomis, BD A1 - Anthony A. Arendt A1 - J J McCarthy A1 - Camp, J VL - 59 ER - TY - JOUR T1 - Challenges to Understanding the Dynamic Response of Greenland's Marine Terminating Glaciers to Oceanic and Atmospheric Forcing JF - Bulletin of the American Meteorological Society Y1 - 2013 A1 - Straneo, Fiammetta A1 - Heimbach, Patrick A1 - Sergienko, Olga A1 - Hamilton, Gordon A1 - Catania, Ginny A1 - Griffies, Stephen A1 - Hallberg, Robert A1 - Jenkins, Adrian A1 - Joughin, Ian A1 - Motyka, Roman A1 - Pfeffer, W. Tad A1 - Stephen F. Price A1 - Eric Rignot A1 - Scambos, Ted A1 - Martin Truffer A1 - Vieli, Andreas VL - 94 UR - http://dx.doi.org/10.1175/BAMS-D-12-00100.1 IS - 8 ER - TY - JOUR T1 - Changing basal conditions during the speed-up of Jakobshavn Isbræ, Greenland JF - The Cryosphere Y1 - 2013 A1 - Habermann, M A1 - Martin Truffer A1 - Maxwell, D VL - 7 IS - 6 ER - TY - JOUR T1 - Channelized ice melting in the ocean boundary layer beneath Pine Island Glacier, Antarctica. JF - Science (New York, N.Y.) Y1 - 2013 A1 - Stanton, T P A1 - Shaw, W J A1 - Truffer, M. A1 - Corr, H F J A1 - Peters, L E A1 - Riverman, K L A1 - Bindschadler, R A1 - Holland, D M A1 - Anandakrishnan, S KW - Antarctic Regions KW - Freezing KW - Ice Cover KW - Oceans and Seas AB - Ice shelves play a key role in the mass balance of the Antarctic ice sheets by buttressing their seaward-flowing outlet glaciers; however, they are exposed to the underlying ocean and may weaken if ocean thermal forcing increases. An expedition to the ice shelf of the remote Pine Island Glacier, a major outlet of the West Antarctic Ice Sheet that has rapidly thinned and accelerated in recent decades, has been completed. Observations from geophysical surveys and long-term oceanographic instruments deployed down bore holes into the ocean cavity reveal a buoyancy-driven boundary layer within a basal channel that melts the channel apex by 0.06 meter per day, with near-zero melt rates along the flanks of the channel. A complex pattern of such channels is visible throughout the Pine Island Glacier shelf. VL - 341 UR - http://www.ncbi.nlm.nih.gov/pubmed/24031016 ER - TY - JOUR T1 - Does calving matter? Evidence for significant submarine melt JF - Earth and Planetary Science Letters Y1 - 2013 A1 - Timothy C. Bartholomaus A1 - Chris F. Larsen A1 - Shad OʼNeel VL - 380 UR - http://www.sciencedirect.com/science/article/pii/S0012821X13004408 ER - TY - JOUR T1 - Estimating glacier snow accumulation from backward calculation of melt and snowline tracking JF - Annals of Glaciology Y1 - 2013 A1 - Hulth, J. A1 - DENBY, C.R. A1 - Regine Hock VL - 54 ER - TY - JOUR T1 - The evolution of crystal fabric in ice sheets and its link to climate history JF - Journal of Glaciology Y1 - 2013 A1 - Joseph H Kennedy A1 - Erin C Pettit A1 - Di Prinzio, Carlos L AB - The evolution of preferred crystal-orientation fabrics is strongly sensitive to the initial fabric and texture. A perturbation in climate can induce variations in fabric and texture in the firn. Feedbacks between fabric evolution and ice deformation can enhance these variations through time and depth in an ice sheet. We model the evolution of fabric under vertical uniaxial compression and pure shear regimes typical of ice divides. Using an analytic anisotropic flow law applied to an aggregate of distinct ice crystals, the model evolves the fabric and includes parameterizations of crystal growth, polygonization and migration recrystallization. Stress and temperature history drive the fabric evolution. Using this model, we explore the evolution of a subtle variation in near-surface fabric using both constant applied stress and a stress-temperature history based on data from Taylor Dome, East Antarctica. Our model suggests that a subtle variation in fabric caused by climate perturbations will be preserved through time and depth in an ice sheet. The stress history and polygonization rate primarily control the magnitude of the preserved climate signal. These results offer the possibility of extracting information about past climate directly from ice fabrics. VL - 59 UR - http://glacierstest.gi.alaska.edu/sites/default/files/bibfiles/t12J159.pdf IS - 214 ER - TY - JOUR T1 - Flow velocities of Alaskan glaciers JF - Nat Commun Y1 - 2013 A1 - Evan W. Burgess A1 - Richard R. Forster A1 - Chris F. Larsen VL - 4 UR - http://dx.doi.org/10.1038/ncomms3146 ER - TY - JOUR T1 - Geodetic Mass Balance of Glaciers in the Central Brooks Range, Alaska, USA, from 1970 to 2001 JF - Arctic, Antarctic, and Alpine Research Y1 - 2013 A1 - Geck, Jason A1 - Regine Hock A1 - Nolan, Matt VL - 45 IS - 1 ER - TY - RPRT T1 - Glaciers and ice caps (outside Greenland) Y1 - 2013 A1 - G. J. Wolken A1 - Martin J. Sharp A1 - M-L. Geai A1 - D. Burges A1 - Anthony A. Arendt A1 - Bert Wouters JF - State of the Climate in 2012 PB - Bull. Amer. Meteor. Soc. 94(7), S143 ER - TY - JOUR T1 - Hindcasting to measure ice sheet model sensitivity to initial states JF - The Cryosphere Y1 - 2013 A1 - Andy Aschwanden A1 - Gudfinna Aðalgeirsdóttir A1 - Constantine Khroulev VL - 7 IS - 4 ER - TY - JOUR T1 - Ice-sheet model sensitivities to environmental forcing and their use in projecting future sea-level (The SeaRISE Project) JF - J. Glaciol Y1 - 2013 A1 - Robert A. Bindschadler A1 - Nowicki, Sophie A1 - Abe-Ouchi, Ayako A1 - Andy Aschwanden A1 - Choi, Hyeungu A1 - Fastook, Jim A1 - Granzow, Glen A1 - Greve, Ralf A1 - Gutowski, Gail A1 - Herzfeld, Ute A1 - others VL - 59 IS - 214 ER - TY - JOUR T1 - Insights into spatial sensitivities of ice mass response to environmental change from the SeaRISE ice sheet modeling project II: Greenland JF - J. Geophys. Res. Y1 - 2013 A1 - Nowicki, Sophie A1 - Robert A. Bindschadler A1 - Abe-Ouchi, Ayako A1 - Andy Aschwanden A1 - E. Bueler A1 - Choi, Hyeungu A1 - Fastook, Jim A1 - Granzow, Glen A1 - Greve, Ralf A1 - Gutowski, Gail A1 - Herzfeld, Ute A1 - Jackson, Charles A1 - Jesse V Johnson A1 - Constantine Khroulev A1 - Larour, Eric A1 - Anders Levermann A1 - Lipscomb, William H. A1 - Maria A. Martin A1 - Morlighem, Mathieu A1 - Parizek, Byron R. A1 - David Pollard A1 - Stephen F. Price A1 - Ren, Diandong A1 - Eric Rignot A1 - Fuyuki Saito A1 - Tatsuru Sato A1 - Seddik, Hakime A1 - Seroussi, Helene A1 - Takahashi, Kunio A1 - Walker, Ryan A1 - Wang, Wei Li VL - 118 UR - http://doi.wiley.com/10.1002/jgrf.20076 ER - TY - JOUR T1 - Insights into spatial sensitivities of ice mass response to environmental change from the SeaRISE ice sheet modeling project I: Antarctica JF - J. Geophys. Res. Y1 - 2013 A1 - Nowicki, Sophie A1 - Robert A. Bindschadler A1 - Abe-Ouchi, Ayako A1 - Andy Aschwanden A1 - E. Bueler A1 - Choi, Hyeungu A1 - Fastook, Jim A1 - Granzow, Glen A1 - Greve, Ralf A1 - Gutowski, Gail A1 - Herzfeld, Ute A1 - Jackson, Charles A1 - Jesse V Johnson A1 - Constantine Khroulev A1 - Larour, Eric A1 - Anders Levermann A1 - Lipscomb, William H. A1 - Maria A. Martin A1 - Morlighem, Mathieu A1 - Parizek, Byron R. A1 - David Pollard A1 - Stephen F. Price A1 - Ren, Diandong A1 - Eric Rignot A1 - Fuyuki Saito A1 - Tatsuru Sato A1 - Seddik, Hakime A1 - Seroussi, Helene A1 - Takahashi, Kunio A1 - Walker, Ryan A1 - Wang, Wei Li VL - 118 UR - http://doi.wiley.com/10.1002/jgrf.20081 ER - TY - JOUR T1 - Low-frequency radar sounding of temperate ice masses in Southern Alaska JF - Geophysical Research Letters Y1 - 2013 A1 - Eric Rignot A1 - Mouginot, J. A1 - Chris F. Larsen A1 - Gim, Y. A1 - Kirchner, D. KW - Alaska KW - bed topography KW - glaciology KW - mass balance KW - radar KW - thickness AB - We present the Warm Ice Sounding Explorer (WISE), a low-frequency (2.5 MHz) radar for the sounding of temperate ice. WISE deployment in southern Alaska in 2008 and 2012 provides comprehensive measurements of glacier thickness, reveals deep valleys beneath glaciers and the full extent of zones grounded below sea level. The east branch of Columbia Glacier is deeper that its main branch and remains below sea level 20 km farther inland. Ice is 1000 m deep on Tazlina Glacier. On Bering glacier, two sills separate three deep bed depressions (>1200 m) that coincide with the dynamic balance lines during surges. The piedmont lobe of Malaspina Glacier and the lower reaches of Hubbard Glacier are entirely grounded below sea level 40 and 10 km, respectively, from their termini. Knowledge of ice thickness in these regions helps better understand their glacier dynamics, mass balance, and impact on sea level. UR - http://dx.doi.org/10.1002/2013GL057452 ER - TY - JOUR T1 - Mass balance in the Glacier Bay area of Alaska, USA, and British Columbia, Canada, 1995–2011, using airborne laser altimetry JF - Journal of Glaciology Y1 - 2013 A1 - Johnson, Austin J A1 - Chris F. Larsen A1 - Murphy, Nathaniel A1 - Anthony A. Arendt A1 - Zirnheld, S Lee VL - 59 IS - 216 ER - TY - JOUR T1 - A new inventory of mountain glaciers and ice caps for the Antarctic periphery JF - Annals of Glaciology Y1 - 2013 A1 - Andrew Bliss A1 - Regine Hock A1 - J. Graham Cogley VL - 54 IS - 63 ER - TY - JOUR T1 - A new semi-automatic approach for dividing glacier complexes into individual glaciers JF - Journal of Glaciology Y1 - 2013 A1 - Kienholz, C. A1 - Regine Hock A1 - Anthony A. Arendt VL - 59 IS - 217 ER - TY - JOUR T1 - A nonsmooth Newton multigrid method for a hybrid, shallow model of marine ice sheets JF - Contemporary Mathematics Y1 - 2013 A1 - Guillaume Jouvet A1 - E. Bueler A1 - Carsten Gräser A1 - Kornhuber, Ralf VL - 586 ER - TY - JOUR T1 - An open ocean region in Neoproterozoic glaciations would have to be narrow to allow equatorial ice sheets JF - Geophysical Research Letters Y1 - 2013 A1 - Rodehacke, Christian B. A1 - Voigt, Aiko A1 - Ziemen, Florian A1 - Abbot, Dorian S. KW - ice sheet modeling KW - Neoproterozoic glaciations KW - snowball Earth AB - A major goal of understanding Neoproterozoic glaciations and determining their effect on the evolution of life and Earth's atmosphere is establishing whether and how much open ocean there was during them. Geological evidence tells us that continental ice sheets had to flow into the ocean near the equator during these glaciations. Here we drive the Parallel Ice Sheet Model with output from four simulations of the ECHAM5/Max Planck Institute Ocean Model atmosphere-ocean general circulation model with successively narrower open ocean regions. We find that extensive equatorial ice sheets form on marine margins if sea ice extends to within about 20° latitude of the equator or less (Jormungand-like and hard snowball states), but do not form if there is more open ocean than this. Given uncertainty in topographical reconstruction and ice sheet ablation parameterizations, we perform extensive sensitivity tests to confirm the robustness of our main conclusions. VL - 40 UR - http://dx.doi.org/10.1002/2013GL057582 ER - TY - JOUR T1 - The propagation of a surge front on Bering Glacier, Alaska, 2001–2011 JF - Annals of Glaciology Y1 - 2013 A1 - Turrin, James A1 - Richard R. Forster A1 - Chris F. Larsen A1 - Sauber, Jeanne AB - Bering Glacier, Alaska, USA, has a ∼20 year surge cycle, with its most recent surge reaching the terminus in 2011. To study this most recent activity a time series of ice velocity maps was produced by applying optical feature-tracking methods to Landsat-7 ETM+ imagery spanning 2001–11. The velocity maps show a yearly increase in ice surface velocity associated with the down-glacier movement of a surge front. In 2008/09 the maximum ice surface velocity was 1.5 ± 0.017 km a–1 in the mid-ablation zone, which decreased to 1.2 ± 0.015 km a–1 in 2009/10 in the lower ablation zone, and then increased to nearly 4.4 ± 0.03 km a–1 in summer 2011 when the surge front reached the glacier terminus. The surge front propagated down-glacier as a kinematic wave at an average rate of 4.4 ± 2.0 km a–1 between September 2002 and April 2009, then accelerated to 13.9 ± 2.0 km a–1 as it entered the piedmont lobe between April 2009 and September 2010. The wave seems to have initiated near the confluence of Bering Glacier and Bagley Ice Valley as early as 2001, and the surge was triggered in 2008 further down-glacier in the mid-ablation zone after the wave passed an ice reservoir area. VL - 54 UR - http://www.ingentaconnect.com/content/igsoc/agl/2013/00000054/00000063/art00024 ER - TY - JOUR T1 - Rapid Submarine Melting Driven by Subglacial Discharge, LeConte Glacier, Alaska JF - Geophysical Research Letters Y1 - 2013 A1 - Roman J. Motyka A1 - Dryer, W. P. A1 - Jason M Amundson A1 - Martin Truffer A1 - Mark Fahnestock KW - frontal ablation KW - submarine melting KW - tidewater glaciers AB - We show that subglacial freshwater discharge is the principal process driving high rates of submarine melting at tidewater glaciers. This buoyant discharge draws in warm seawater, entraining it in a turbulent upwelling flow along the submarine face that melts glacier ice. To capture the effects of subglacial discharge on submarine melting, we conducted 4 days of hydrographic transects during late summer 2012 at LeConte Glacier, Alaska. A major rainstorm allowed us to document the influence of large changes in subglacial discharge. We found strong submarine melt fluxes that increased from 9.1 ± 1.0 to 16.8 ± 1.3 m d−1 (ice face equivalent frontal ablation) as a result of the rainstorm. With projected continued global warming and increased glacial runoff, our results highlight the direct impact that increases in subglacial discharge will have on tidewater outlet systems. These effects must be considered when modeling glacier response to future warming and increased runoff. VL - 40 UR - http://dx.doi.org/10.1002/grl.51011 ER - TY - JOUR T1 - Rapid thinning of lake-calving Yakutat Glacier and the collapse of the Yakutat Icefield, southeast Alaska, USA JF - J. Glaciol. Y1 - 2013 A1 - Trüssel, Barbara L. A1 - Motyka, Roman J. A1 - Truffer, M. A1 - Larsen, C. F. VL - 59 UR - http://www.igsoc.org/journal/59/213/t12J081.html ER - TY - JOUR T1 - Recent air and ground temperature increases at Tarfala Research Station, Sweden JF - Polar Research Y1 - 2013 A1 - Ulf Jonsell A1 - Regine Hock A1 - Martial Duguay KW - Air temperature KW - climate change KW - degree-days KW - lapse rate KW - NAO KW - permafrost AB - Long-term data records are essential to detect and understand environmental change, in particular in generally data-sparse high-latitude and high-altitude regions. Here, we analyse a 47-year air temperature record (1965-2011) at Tarfala Research Station (67° 54.7'N, 18° 36.7'E, 1135 m a.s.l.) in northern Sweden, and a nearby 11-year record of 100-m-deep ground temperature (2001-11; 1540 m a.s.l.). The air temperature record shows a mean annual air temperature of -3.5±0.9°C (±1 standard deviation s) and a linear warming trend of ±0.042°C yr-1. The warming trend shows large month-to-month variations with the largest trend in January followed by October. Also, the number of days with positive mean daily temperatures and positive degree-day sums has increased during the last two decades compared to the previous period. Temperature lapse rates derived from the mean daily Tarfala record and an air temperature record at the borehole site average 4.5°C km-1 and tend to be higher in summer than in winter. Mean summer air temperatures at Tarfala explain 76% of the variance of the summer glacier mass balance of nearby Storglacia¨ren. Consistent with the observed increase in Tarfala’s air temperature, the ground temperature record shows significant permafrost warming with the largest trend (0.047°C yr-1) found at 20 m depth.Keywords: Air temperature; climate change; permafrost; lapse rate; degree-days; NAO(Published: 15 July 2013)Citation: Polar Research 2013, 32, 19807, http://dx.doi.org/10.3402/polar.v32i0.19807 VL - 32 UR - http://www.polarresearch.net/index.php/polar/article/view/19807 ER - TY - JOUR T1 - A Reconciled Estimate of Glacier Contributions to Sea Level Rise: 2003 to 2009 JF - Science Y1 - 2013 A1 - Alex S. Gardner A1 - Geir Moholdt A1 - J. Graham Cogley A1 - Bert Wouters A1 - Anthony A. Arendt A1 - Wahr, John A1 - Berthier, Etienne A1 - Regine Hock A1 - W. Tad Pfeffer A1 - Georg Kaser A1 - Ligtenberg, Stefan R. M. A1 - Bolch, Tobias A1 - Martin J. Sharp A1 - Jon Ove Hagen A1 - van den Broeke, Michiel R. A1 - Paul, Frank AB - Glaciers distinct from the Greenland and Antarctic Ice Sheets are losing large amounts of water to the world’s oceans. However, estimates of their contribution to sea level rise disagree. We provide a consensus estimate by standardizing existing, and creating new, mass-budget estimates from satellite gravimetry and altimetry and from local glaciological records. In many regions, local measurements are more negative than satellite-based estimates. All regions lost mass during 2003–2009, with the largest losses from Arctic Canada, Alaska, coastal Greenland, the southern Andes, and high-mountain Asia, but there was little loss from glaciers in Antarctica. Over this period, the global mass budget was –259 ± 28 gigatons per year, equivalent to the combined loss from both ice sheets and accounting for 29 ± 13% of the observed sea level rise. VL - 340 UR - http://www.sciencemag.org/content/340/6134/852.abstract ER - TY - JOUR T1 - Regional and global projections of twenty-first century glacier mass changes in response to climate scenarios from global climate models JF - Climate Dynamics Y1 - 2013 A1 - Valentina Radić A1 - Andrew Bliss A1 - Beedlow, A.Cody A1 - Regine Hock A1 - Miles, Evan A1 - J. Graham Cogley KW - Global climate models KW - Projections of sea level rise KW - Regional and global glacier mass changes UR - http://dx.doi.org/10.1007/s00382-013-1719-7 ER - TY - JOUR T1 - The role of subsurface heat exchange: energy partitioning at Austfonna ice cap, Svalbard, over 2004-2008 JF - Annals of Glaciology Y1 - 2013 A1 - Torbjørn I. ØSTBY A1 - Schuler, T.V. A1 - Jon Ove Hagen A1 - Regine Hock A1 - C H Reijmer VL - 54 IS - 63 ER - TY - JOUR T1 - On the seasonal freshwater stratification in the proximity of fast-flowing tidewater outlet glaciers in a sub-Arctic sill fjord JF - Journal of Geophysical Research: Oceans Y1 - 2013 A1 - Mortensen, J. A1 - Bendtsen, J. A1 - Roman J. Motyka A1 - Lennert, K. A1 - Martin Truffer A1 - Mark Fahnestock A1 - Rysgaard, S. KW - fjord KW - freshwater sources and their distribution KW - Greenland Ice Sheet KW - subglacial freshwater fraction model KW - subsurface heat sources for glacial ice melt KW - tidewater outlet glaciers AB - The Greenland Ice Sheet releases large amounts of freshwater into the fjords around Greenland and many fjords are in direct contact with the ice sheet through tidewater outlet glaciers. Here we present the first seasonal hydrographic observations from the inner part of a sub-Arctic fjord, relatively close to and within 4–50 km of a fast-flowing tidewater outlet glacier. This region is characterized by a dense glacial and sea ice cover. Freshwater from runoff, subglacial freshwater (SgFW) discharge, glacial, and sea ice melt are observed above 50–90 m depth. During summer, SgFW and subsurface glacial melt mixed with ambient water are observed as a layered structure in the temperature profiles below the low-saline summer surface layer (<7 m). During winter, the upper water column is characterized by stepwise halo- and thermoclines formed by mixing between deeper layers and the surface layer influenced by ice melt. The warm (T > 1°C) intermediate water mass is a significant subsurface heat source for ice melt. We analyze the temperature and salinity profiles observed in late summer with a thermodynamic mixing model and determine the total freshwater content in the layer below the summer surface layer to be between 5% and 11%. The total freshwater contribution in this layer from melted glacial ice was estimated to be 1–2%, while the corresponding SgFW was estimated to be 3–10%. The winter measurements in the subsurface halocline layer showed a total freshwater content of about 1% and no significant contribution from SgFW. VL - 118 UR - http://dx.doi.org/10.1002/jgrc.20134 ER - TY - JOUR T1 - Southeast Greenland high accumulation rates derived from firn cores and ground-penetrating radar JF - Annals of Glaciology Y1 - 2013 A1 - Miège, C. A1 - Richard R. Forster A1 - Box, J.E. A1 - Evan W. Burgess A1 - McConnell, J.R. A1 - Pasteris, D.R. A1 - Spikes, V.B. VL - 54 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84881651457&partnerID=40&md5=6aa824682a2fef9009d445649f72c298 ER - TY - JOUR T1 - Summer melt regulates winter glacier flow speeds throughout Alaska JF - Geophysical Research Letters Y1 - 2013 A1 - Evan W. Burgess A1 - Chris F. Larsen A1 - Richard R. Forster KW - Alaska KW - Ice Dynamics KW - Mountain Glaciers KW - Offset Tracking KW - Sub-Glacial Hydrology KW - Winter AB - Predicting how climate change will affect glacier and ice sheet flow speeds remains a large hurdle towards accurate sea level rise forecasting. Increases in surface melt rates are known to accelerate glacier flow in summer, whereas in winter, flow speeds are believed to be relatively invariant. Here we show that wintertime flow speeds on nearly all major glaciers throughout Alaska are not only variable but are inversely related to melt from preceding summers. For each additional meter of summertime melt, we observe an 11% decrease in wintertime velocity on glaciers of all sizes, geometries, climates and bed types. This dynamic occurs because inter-annual differences in summertime melt affect how much water is retained in the sub-glacial system during winter. The ubiquity of the dynamic indicates it occurs globally on glaciers and ice sheets not frozen to their beds and thus constitutes a new mechanism affecting sea level rise projections. UR - http://dx.doi.org/10.1002/2013GL058228 ER - TY - JOUR T1 - Surface velocity and ice discharge of the ice cap on King George Island, Antarctica JF - Annals of Glaciology Y1 - 2013 A1 - Batuhan Osamanoglu A1 - M Braun A1 - Regine Hock A1 - Navarro, Francisco VL - 54 IS - 63 ER - TY - JOUR T1 - Underwater sound radiated by bubbles released by melting glacier ice JF - The Journal of the Acoustical Society of America Y1 - 2013 A1 - Lee, Kevin M A1 - Wilson, Preston S A1 - Pettit, Erin C PB - Acoustical Society of America VL - 134 ER - TY - JOUR T1 - Variable penetration depth of interferometric synthetic aperture radar signals on Alaska glaciers: a cold surface layer hypothesis JF - Annals of Glaciology Y1 - 2013 A1 - Alessio Gusmeroli A1 - Anthony A. Arendt A1 - D K Atwood A1 - B. Kampes A1 - M. Sanford A1 - J. Young VL - 54 IS - 64 ER - TY - JOUR T1 - Accelerated contributions of Canada's Baffin and Bylot Island glaciers to sea level rise over the past half century JF - The Cryosphere Y1 - 2012 A1 - Alex S. Gardner A1 - Geir Moholdt A1 - Anthony A. Arendt A1 - Bert Wouters VL - 6 ER - TY - JOUR T1 - Analysis of low-frequency seismic signals generated during a multiple-iceberg calving event at Jakobshavn Isbræ, Greenland JF - Journal of Geophysical Research Y1 - 2012 A1 - Walter, F. A1 - Amundson, J. M. A1 - O'Neel, S. A1 - Truffer, M. A1 - Fahnestock, M.A. A1 - Fricker, H. A. KW - calving KW - glacier KW - iceberg KW - seismology VL - 117 UR - http://www.agu.org/pubs/crossref/2012/2011JF002132.shtml ER - TY - JOUR T1 - Borehole temperatures reveal details of 20th century warming at Bruce Plateau, Antarctic Peninsula JF - The Cryosphere Y1 - 2012 A1 - Zagorodnov, V A1 - Nagornov, O A1 - Scambos, TA A1 - Muto, A A1 - Mosley-Thompson, E A1 - Erin C Pettit A1 - Tyuflin, S PB - Copernicus GmbH VL - 6 ER - TY - JOUR T1 - Calving seismicity from iceberg–sea surface interactions JF - Journal of Geophysical Research Y1 - 2012 A1 - Timothy C. Bartholomaus A1 - Chris F. Larsen A1 - Shad OʼNeel A1 - West, M. VL - 117 ER - TY - JOUR T1 - Conventional versus reference-surface mass balance JF - Journal of Glaciology Y1 - 2012 A1 - Huss, M. A1 - Regine Hock A1 - Bauder, A. A1 - Funk, M. VL - 58 ER - TY - JOUR T1 - The crystal fabric of ice from full-waveform borehole sonic logging JF - Journal of Geophysical Research: Earth Surface (2003–2012) Y1 - 2012 A1 - Alessio Gusmeroli A1 - Erin C Pettit A1 - Joseph H Kennedy A1 - Ritz, Catherine PB - Wiley Online Library VL - 117 ER - TY - JOUR T1 - A detailed view into the eruption clouds of Santiaguito volcano, Guatemala, using Doppler radar JF - Journal of Geophysical Research: Solid Earth Y1 - 2012 A1 - Scharff, L. A1 - Ziemen, F. A1 - Hort, M. A1 - Gerst, A. A1 - Johnson, J. B. KW - Doppler radar KW - eruption dynamics KW - Santiaguito volcano AB - Using Doppler radar technology we are able to show that eruptions at Santiaguito volcano, Guatemala, are comprised of multiple explosive degassing pulses occurring at a frequency of 0.2 to 0.3 Hz. The Doppler radar system was installed about 2.7 km away from the active dome on the top of Santa Maria volcano. During four days of continuous measurement 157 eruptive events were recorded. The Doppler radar data reveals a vertical uplift of the dome surface of about 50 cm immediately prior to a first degassing pulse. Particle velocities range from 10 to 15 m/s (in the line of sight of the radar). In 80% of the observed eruptions a second degassing pulse emanates from the dome with significantly higher particle velocities (20–25 m/s again line of sight) and increased echo power, which implies an increase in mass flux. We carry out numerical experiments of ballistic particle transport and calculate corresponding synthetic radar signals. These calculations show that the observations are consistent with a pulsed release of material from the dome of Santiaguito volcano. VL - 117 UR - http://dx.doi.org/10.1029/2011JB008542 ER - TY - JOUR T1 - An enthalpy formulation for glaciers and ice sheets JF - J. Glaciol. Y1 - 2012 A1 - Andy Aschwanden A1 - E. Bueler A1 - Constantine Khroulev A1 - Blatter, H. VL - 58 ER - TY - JOUR T1 - Gravity and uplift rates observed in southeast Alaska and their comparison with GIA model predictions JF - Journal of Geophysical Research Y1 - 2012 A1 - Tatsuru Sato A1 - Miura, S. A1 - Sun, W. A1 - Sugano, T. A1 - Jeffrey T. Freymueller A1 - Chris F. Larsen A1 - Ohta, Y. A1 - Fujimoto, H. A1 - Inazu, D. A1 - Roman J. Motyka VL - 117 ER - TY - JOUR T1 - Ice-core net snow accumulation and seasonal snow chemistry at a temperate-glacier site: Mount Waddington, southwest British Columbia, Canada JF - Journal of Glaciology Y1 - 2012 A1 - Neff, Peter D A1 - Steig, Eric J A1 - Clark, Douglas H A1 - McConnell, Joseph R A1 - Pettit, Erin C A1 - Menounos, Brian PB - International Glaciological Society VL - 58 ER - TY - JOUR T1 - Ice-core net snow accumulation and seasonal snow chemistry at a temperate-glacier site: Mount Waddington, southwest British Columbia, Canada JF - Journal of Glaciology Y1 - 2012 A1 - Peter, D A1 - Steig, Eric J A1 - Clark, Douglas H A1 - McConnell, Joseph R A1 - Erin, C VL - 58 ER - TY - JOUR T1 - Listening to Glaciers: Passive Hydroacoustics Near Marine-Terminating Glaciers JF - Oceanography Y1 - 2012 A1 - Erin C Pettit A1 - Nystuen, Jeffrey A A1 - O'Neel, Shad PB - The Oceanography Society (TOS) VL - 25 ER - TY - RPRT T1 - Mountain Glaciers and ice caps Y1 - 2012 A1 - Martin J. Sharp A1 - M. Ananicheva A1 - Anthony A. Arendt A1 - Jon Ove Hagen A1 - Regine Hock A1 - E. Josberger A1 - R. D. Moore A1 - W. Tad Pfeffer A1 - G. J. Wolken JF - Snow, Water, Ice and Permafrost in the Arctic (SWIPA): Climate Change and the Cryosphere. PB - Arctic Monitoring and Assessment Programme (AMAP) CY - Oslo, Norway SN - 978-82-7971-071-4 ER - TY - JOUR T1 - Observing calving-generated ocean waves with coastal broadband seismometers, Jakobshavn Isbræ, Greenland JF - Annals Of Glaciology Y1 - 2012 A1 - Amundson, J. M. A1 - Clinton, John F A1 - Fahnestock, M.A. A1 - Truffer, M. A1 - Motyka, Roman J. A1 - Lüthi, Martin P. VL - 53 ER - TY - JOUR T1 - Outlet glacier response to forcing over hourly to interannual timescales, Jakobshavn Isbræ, Greenland JF - Journal of Glaciology Y1 - 2012 A1 - Podrasky, David A1 - Martin Truffer A1 - Mark Fahnestock A1 - Jason M Amundson A1 - Cassotto, Ryan A1 - Ian Joughin VL - 58 ER - TY - JOUR T1 - Outlet glacier response to forcing over hourly to interannual timescales, Jakobshavn Isbræ, Greenland JF - J. Glaciol. Y1 - 2012 A1 - Podrasky, David A1 - Truffer, Martin A1 - Fahnestock, Mark A1 - Amundson, Jason M. A1 - Cassotto, Ryan A1 - Joughin, Ian VL - 58 UR - http://openurl.ingenta.com/content/xref?genre=article{&}issn=0022-1430{&}volume=58{&}issue=212{&}spage=1212 ER - TY - JOUR T1 - Passive underwater acoustic evolution of a calving event JF - Annals of Glaciology Y1 - 2012 A1 - Erin C Pettit VL - 53 ER - TY - JOUR T1 - Plate margin deformation and active tectonics along the northern edge of the Yakutat Terrane in the Saint Elias Orogen, Alaska, and Yukon, Canada JF - Geosphere Y1 - 2012 A1 - Bruhn, R.L. A1 - Sauber, J. A1 - Cotton, M.M. A1 - Pavlis, T.L. A1 - Evan W. Burgess A1 - Ruppert, N. A1 - Richard R. Forster VL - 8 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84873486244&partnerID=40&md5=6b0147233ff3aeb0e48bf9b253b6c6ec ER - TY - JOUR T1 - Reconstruction of basal properties in ice sheets using iterative inverse methods JF - Journal of Glaciology Y1 - 2012 A1 - Habermann, M. A1 - Maxwell, D. A1 - Martin Truffer VL - 58 ER - TY - JOUR T1 - Seasonal to decadal scale variations in the surface velocity of Jakobshavn Isbrae, Greenland: Observation and model-based analysis JF - J. Geophys. Res. Y1 - 2012 A1 - Joughin, Ian A1 - Smith, B. E. A1 - Howat, I. M. A1 - Floricioiu, Dana A1 - Alley, Richard B. A1 - Truffer, M. A1 - Fahnestock, M.A. KW - glacier KW - glaciology KW - ice stream VL - 117 UR - http://www.agu.org/pubs/crossref/2012/2011JF002110.shtml ER - TY - JOUR T1 - Seismic multiplet response triggered by melt at Blood Falls, Taylor Glacier, Antarctica JF - Journal of Geophysical Research: Earth Surface (2003–2012) Y1 - 2012 A1 - Carmichael, Joshua D A1 - Erin C Pettit A1 - Hoffman, Matt A1 - Fountain, Andrew A1 - Hallet, Bernard VL - 117 ER - TY - JOUR T1 - Steady, shallow ice sheets as obstacle problems: well-posedness and finite element approximation JF - SIAM Journal on Applied Mathematics Y1 - 2012 A1 - Guillaume Jouvet A1 - E. Bueler VL - 72 ER - TY - JOUR T1 - Surge dynamics on Bering Glacier, Alaska, in 2008–2011 JF - The Cryosphere Discuss Y1 - 2012 A1 - Evan W. Burgess A1 - Richard R. Forster A1 - Chris F. Larsen A1 - M Braun VL - 6 ER - TY - JOUR T1 - Using surface velocities to calculate ice thickness and bed topography: a case study at Columbia Glacier, Alaska, USA JF - Journal of Glaciology Y1 - 2012 A1 - R  W McNabb A1 - Regine Hock A1 - Shad OʼNeel A1 - L  A Rasmussen A1 - Ahn, Y. A1 - M Braun A1 - H Conway A1 - Herreid, S. A1 - Ian Joughin A1 - W. Tad Pfeffer A1 - B  E Smith A1 - Martin Truffer VL - 58 IS - 212 ER - TY - JOUR T1 - Analysis of seasonal variations in mass balance and meltwater discharge of the tropical Zongo Glacier by application of a distributed energy balance model JF - Journal of Geophysical Research Y1 - 2011 A1 - Sicart, JE A1 - Regine Hock A1 - Ribstein, P. A1 - Litt, M. A1 - Ramirez, E. VL - 116 ER - TY - JOUR T1 - Assessing the Status of Alaska's Glaciers JF - Science Y1 - 2011 A1 - Anthony A. Arendt VL - 332 ER - TY - JOUR T1 - Climatic mass balance of the ice cap Vestfonna, Svalbard: A spatially distributed assessment using ERA-Interim and MODIS data JF - Journal of Geophysical Research Y1 - 2011 A1 - Möller, M. A1 - Finkelnburg, R. A1 - M Braun A1 - Regine Hock A1 - Ulf Jonsell A1 - Pohjola, V.A. A1 - Scherer, D. A1 - Schneider, C. VL - 116 ER - TY - JOUR T1 - A complex relationship between calving glaciers and climate JF - Eos, Transactions American Geophysical Union Y1 - 2011 A1 - Post, Austin A1 - Shad OʼNeel A1 - Roman J. Motyka A1 - Streveler, Gregory KW - climate KW - glaciers AB - Many terrestrial glaciers are sensitive indicators of past and present climate change as atmospheric temperature and snowfall modulate glacier volume. However, climate interpretations based on glacier behavior require careful selection of representative glaciers, as was recently pointed out for surging and debris-covered glaciers, whose behavior often defies regional glacier response to climate [Yde and Paasche, 2010]. Tidewater calving glaciers (TWGs)—mountain glaciers whose termini reach the sea and are generally grounded on the seafloor—also fall into the category of non-representative glaciers because the regional-scale asynchronous behavior of these glaciers clouds their complex relationship with climate. TWGs span the globe; they can be found both fringing ice sheets and in high-latitude regions of each hemisphere. TWGs are known to exhibit cyclic behavior, characterized by slow advance and rapid, unstable retreat, largely independent of short-term climate forcing. This so-called TWG cycle, first described by Post [1975], provides a solid foundation upon which modern investigations of TWG stability are built. Scientific understanding has developed rapidly as a result of the initial recognition of their asynchronous cyclicity, rendering greater insight into the hierarchy of processes controlling regional behavior. This has improved the descriptions of the strong dynamic feedbacks present during retreat, the role of the ocean in TWG dynamics, and the similarities and differences between TWG and ice sheet outlet glaciers that can often support floating tongues. VL - 92 UR - http://dx.doi.org/10.1029/2011EO370001 ER - TY - JOUR T1 - The crossover stress, anisotropy and the ice flow law at Siple Dome, West Antarctica JF - Journal of Glaciology Y1 - 2011 A1 - Erin C Pettit A1 - Waddington, Edwin D A1 - Harrison, William D A1 - Thorsteinsson, Throstur A1 - Elsberg, Daniel A1 - Morack, John A1 - Zumberge, Mark A PB - International Glaciological Society VL - 57 ER - TY - JOUR T1 - Existence and stability of steady-state solutions of the shallow-ice-sheet equation by an energy-minimization approach JF - Journal of Glaciology Y1 - 2011 A1 - Guillaume Jouvet A1 - Rappaz, J. A1 - E. Bueler A1 - Blatter, H. VL - 57 UR - http://www.ingentaconnect.com/content/igsoc/jog/2011/00000057/00000202/art00016 ER - TY - JOUR T1 - From ice-shelf tributary to tidewater glacier: continued rapid recession, acceleration and thinning of Rohss Glacier following the 1995 collapse of the Prince Gustav Ice Shelf, Antarctic Peninsula JF - Journal of Glaciology Y1 - 2011 A1 - Glasser, NF A1 - Scambos, TA A1 - Bohlander, J. A1 - Martin Truffer A1 - Erin C Pettit A1 - Davies, BJ VL - 57 UR - http://openurl.ingenta.com/content/xref?genre=article&issn=0022-1430&volume=57&issue=203&spage=397 ER - TY - JOUR T1 - Glossary of glacier mass balance and related terms JF - IHP-VII Technical Documents in Hydrology Y1 - 2011 A1 - J. Graham Cogley A1 - Regine Hock A1 - L  A Rasmussen A1 - Anthony A. Arendt A1 - Bauder, A. A1 - Braithwaite, RJ A1 - Jansson, P. A1 - Georg Kaser A1 - Möller, M. A1 - Nicholson, L. A1 - others VL - 86 ER - TY - JOUR T1 - Greenland Ice Sheet surface mass balance 1870 to 2010 based on Twentieth Century Reanalysis, and links with global climate forcing JF - Journal of Geophysical Research D: Atmospheres Y1 - 2011 A1 - Hanna, E. A1 - Huybrechts, P. A1 - Cappelen, J. A1 - Steffen, K. A1 - Bales, R.C. A1 - Evan W. Burgess A1 - McConnell, J.R. A1 - Steffensen, J.P. A1 - Van Den Broeke, M. A1 - Wake, L. A1 - Bigg, G. A1 - Griffiths, M. A1 - Savas, D. VL - 116 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84855336557&partnerID=40&md5=9239bc453a5004bd7a1258a2aaa14f07 ER - TY - JOUR T1 - Growth and collapse of the distributed subglacial hydrologic system of Kennicott Glacier, Alaska, USA, and its effects on basal motion JF - Journal of Glaciology Y1 - 2011 A1 - Timothy C. Bartholomaus A1 - Robert S Anderson A1 - Anderson, S.P. VL - 57 ER - TY - JOUR T1 - An increase in crevasse extent, West Greenland: Hydrologic implications JF - Geophysical Research Letters Y1 - 2011 A1 - Colgan, William A1 - Steffen, Konrad A1 - McLamb, W. Scott A1 - Waleed Abdalati A1 - Rajaram, Harihar A1 - Roman J. Motyka A1 - Phillips, Thomas A1 - Robert S Anderson KW - crevasses KW - Greenland KW - mass balance KW - velocity AB - We compare high-resolution 1985 and 2009 imagery to assess changes in crevasse extent in the Sermeq Avannarleq ablation zone, West Greenland. The area occupied by crevasses >2 m wide significantly increased (13 ± 4%) over the 24-year period. This increase consists of an expansion of existing crevasse fields, and is accompanied by widespread changes in crevasse orientation (up to 45°). We suggest that a combination of ice sheet thinning and steepening are responsible for the increase in crevasse extent. We examine the potential impact of this change on the hydrology of the ice sheet. We provide a first-order demonstration that moulin-type drainage is more efficient in transferring meltwater fluctuations to the subglacial system than crevasse-type drainage. As enhanced basal sliding is associated with meltwater “pulses”, an increase in crevasse extent can therefore be expected to result in a net decrease in basal sliding sensitivity. An increase in crevasse extent may also accelerate cryo-hydrologic warming and enhance surface ablation. VL - 38 UR - http://dx.doi.org/10.1029/2011GL048491 ER - TY - JOUR T1 - Karakoram glacier surge dynamics JF - Geophysical Research Letters Y1 - 2011 A1 - Quincey, DJ A1 - M Braun A1 - Glasser, NF A1 - Bishop, MP A1 - I M Howat A1 - Luckman, A. VL - 38 ER - TY - JOUR T1 - Observed glacial changes on the King George Island ice cap, Antarctica, in the last decade JF - Global and Planetary Change Y1 - 2011 A1 - M Rückamp A1 - M Braun A1 - S. Suckro A1 - N. Blindow KW - climate change VL - 79 UR - http://www.sciencedirect.com/science/article/pii/S0921818111001111 ER - TY - JOUR T1 - The Potsdam Parallel Ice Sheet Model (PISM-PIK)-Part 2: Dynamic equilibrium simulation of the Antarctic ice sheet JF - The Cryosphere Y1 - 2011 A1 - Maria A. Martin A1 - Winkelmann, R. A1 - Haseloff, M. A1 - Albrecht, T. A1 - E. Bueler A1 - Constantine Khroulev A1 - Anders Levermann VL - 5 UR - http://www.the-cryosphere.net/5/727/2011/tc-5-727-2011.html ER - TY - JOUR T1 - The Potsdam Parallel Ice Sheet Model (PISM-PIK)–Part 1: Model description JF - The Cryosphere Y1 - 2011 A1 - Winkelmann, R. A1 - Maria A. Martin A1 - Haseloff, M. A1 - Albrecht, T. A1 - E. Bueler A1 - Constantine Khroulev A1 - Anders Levermann VL - 5 UR - http://www.the-cryosphere.net/5/715/2011/tc-5-715-2011.html ER - TY - JOUR T1 - Reevaluation of the viscoelastic and elastic responses to the past and present-day ice changes in Southeast Alaska JF - Tectonophysics Y1 - 2011 A1 - Tatsuru Sato A1 - Chris F. Larsen A1 - Miura, S. A1 - Ohta, Y. A1 - Fujimoto, H. A1 - Sun, W. A1 - Roman J. Motyka A1 - Jeffrey T. Freymueller VL - 511 ER - TY - JOUR T1 - Regionally differentiated contribution of mountain glaciers and ice caps to future sea-level rise JF - Nature Geoscience Y1 - 2011 A1 - Valentina Radić A1 - Regine Hock VL - 4 ER - TY - JOUR T1 - Submarine melting of the 1985 Jakobshavn Isbræ floating tongue and the triggering of the current retreat JF - Journal of Geophysical Research Y1 - 2011 A1 - Roman J. Motyka A1 - Martin Truffer A1 - Mark Fahnestock A1 - Mortensen, J. A1 - Rysgaard, S. A1 - I M Howat VL - 116 ER - TY - JOUR T1 - Surface mass balance, thinning and iceberg production, Columbia Glacier, Alaska, 19482007 JF - Journal of Glaciology Y1 - 2011 A1 - L  A Rasmussen A1 - H Conway A1 - Krimmel, RM A1 - Regine Hock VL - 57 ER - TY - JOUR T1 - 100-year mass changes in the Swiss Alps linked to the Atlantic Multidecadal Oscillation JF - Geophysical research letters Y1 - 2010 A1 - Huss, M. A1 - Regine Hock A1 - Bauder, A. A1 - Funk, M. VL - 37 ER - TY - JOUR T1 - Glacier microseismicity JF - Geology Y1 - 2010 A1 - West, M. A1 - Chris F. Larsen A1 - Martin Truffer A1 - Shad OʼNeel A1 - LeBlanc, Laura AB - We present a framework for interpreting small glacier seismic events based on data collected near the center of Bering Glacier, Alaska, in spring 2007. We find extremely high microseismicity rates (as many as tens of events per minute) occurring largely within a few kilometers of the receivers. A high-frequency class of seismicity is distinguished by dominant frequencies of 20–35 Hz and impulsive arrivals. A low-frequency class has dominant frequencies of 6–15 Hz, emergent onsets, and longer, more monotonic codas. A bimodal distribution of 160,000 seismic events over two months demonstrates that the classes represent two distinct populations. This is further supported by the presence of hybrid waveforms that contain elements of both event types. The high-low-hybrid paradigm is well established in volcano seismology and is demonstrated by a comparison to earthquakes from Augustine Volcano. We build on these parallels to suggest that fluid-induced resonance is likely responsible for the low-frequency glacier events and that the hybrid glacier events may be caused by the rush of water into newly opening pathways. VL - 38 UR - http://geology.gsapubs.org/content/38/4/319.abstract ER - TY - JOUR T1 - Gravity measurements in southeastern Alaska reveal negative gravity rate of change caused by glacial isostatic adjustment JF - Journal of Geophysical Research Y1 - 2010 A1 - Sun, W. A1 - Miura, S. A1 - Tatsuru Sato A1 - Sugano, T. A1 - Jeffrey T. Freymueller A1 - Kaufman, M. A1 - Chris F. Larsen A1 - Cross, R. A1 - Inazu, D. VL - 115 ER - TY - JOUR T1 - Ice mélange dynamics and implications for terminus stability, Jakobshavn Isbræ, Greenland JF - Journal of Geophysical Research Y1 - 2010 A1 - Jason M Amundson A1 - Mark Fahnestock A1 - Martin Truffer A1 - Brown, J. A1 - M P Lüthi A1 - Roman J. Motyka VL - 115 ER - TY - JOUR T1 - Iceberg calving as a primary source of regional-scale glacier-generated seismicity in the St. Elias Mountains, Alaska JF - Journal of Geophysical Research Y1 - 2010 A1 - Shad OʼNeel A1 - Chris F. Larsen A1 - Rupert, N. A1 - Hansen, R. VL - 115 ER - TY - JOUR T1 - Recent and future warm extreme events and high-mountain slope stability JF - Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences Y1 - 2010 A1 - Huggel, C. A1 - Salzmann, N. A1 - Allen, S. A1 - Caplan-Auerbach, J. A1 - L Fischer  A1 - Haeberli, W. A1 - Chris F. Larsen A1 - Schneider, D. A1 - Wessels, R. VL - 368 ER - TY - JOUR T1 - Regional and global volumes of glaciers derived from statistical upscaling of glacier inventory data JF - Journal of Geophysical Research Y1 - 2010 A1 - Valentina Radić A1 - Regine Hock VL - 115 ER - TY - JOUR T1 - Results from the Ice-Sheet Model Intercomparison ProjectHeinrich Event INtercOmparison (ISMIP HEINO) JF - Journal of Glaciology Y1 - 2010 A1 - Calov, Reinhard A1 - Greve, Ralf A1 - Abe-Ouchi, Ayako A1 - E. Bueler A1 - Huybrechts, Philippe A1 - Jesse V Johnson A1 - Frank Pattyn A1 - David Pollard A1 - Ritz, Catherine A1 - Fuyuki Saito A1 - Tarasov, Lev AB - Results from the Heinrich Event INtercOmparison (HEINO) topic of the Ice-Sheet Model Intercomparison Project (ISMIP) are presented. ISMIP HEINO was designed to explore internal large-scale ice-sheet instabilities in different contemporary ice-sheet models. These instabilities are of interest because they are a possible cause of Heinrich events. A simplified geometry experiment reproduces the main characteristics of the Laurentide ice sheet, including the sedimented region over Hudson Bay and Hudson Strait. The model experiments include a standard run plus seven variations. Nine dynamic/thermodynamic ice-sheet models were investigated; one of these models contains a combination of the shallow-shelf (SSA) and shallow-ice approximation (SIA), while the remaining eight models are of SIA type only. Seven models, including the SIA-SSA model, exhibit oscillatory surges with a period of ∼1000 years for a broad range of parameters, while two models remain in a permanent state of streaming for most parameter settings. In a number of models, the oscillations disappear for high surface temperatures, strong snowfall and small sediment sliding parameters. In turn, low surface temperatures and low snowfall are favourable for the ice-surge cycles. We conclude that further improvement of ice-sheet models is crucial for adequate, robust simulations of cyclic large-scale instabilities. VL - 56 UR - http://www.ingentaconnect.com/content/igsoc/jog/2010/00000056/00000197/art00001 ER - TY - JOUR T1 - Sky longwave radiation on tropical Andean glaciers: parameterization and sensitivity to atmospheric variables JF - Journal of Glaciology Y1 - 2010 A1 - Sicart, JE A1 - Regine Hock A1 - Ribstein, P. A1 - Chazarin, J.P. VL - 56 ER - TY - JOUR T1 - A spatially calibrated model of annual accumulation rate on the Greenland Ice Sheet (1958-2007) JF - Journal of Geophysical Research F: Earth Surface Y1 - 2010 A1 - Evan W. Burgess A1 - Richard R. Forster A1 - Box, J.E. A1 - Mosley-Thompson, E. A1 - Bromwich, D.H. A1 - Bales, R.C. A1 - Smith, L.C. VL - 115 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-77951082793&partnerID=40&md5=a6430b7a7a93a85254e4f44589f3b0f4 ER - TY - JOUR T1 - Tectonic block motion and glacial isostatic adjustment in southeast Alaska and adjacent Canada constrained by GPS measurements JF - Journal of Geophysical Research Y1 - 2010 A1 - Elliott, J.L. A1 - Chris F. Larsen A1 - Jeffrey T. Freymueller A1 - Roman J. Motyka VL - 115 ER - TY - JOUR T1 - A unifying framework for iceberg-calving models JF - Journal of Glaciology Y1 - 2010 A1 - Jason M Amundson A1 - Martin Truffer VL - 56 UR - http://openurl.ingenta.com/content/xref?genre=article&issn=0022-1430&volume=56&issue=199&spage=822 ER - TY - JOUR T1 - Using L-band SAR coherence to delineate glacier extent JF - Canadian Journal of Remote Sensing Y1 - 2010 A1 - D K Atwood A1 - Meyer, F. A1 - Anthony A. Arendt VL - 36 ER - TY - JOUR T1 - Vertical distribution of water within the polythermal Storglaciären, Sweden JF - J. Geophys. Res. Y1 - 2010 A1 - Alessio Gusmeroli A1 - Murray, T. A1 - Jansson, P. A1 - Pettersson, R. A1 - Andy Aschwanden A1 - Booth, A. D. VL - 115 UR - http://www.agu.org/pubs/crossref/2010/2009JF001539.shtml ER - TY - JOUR T1 - Volume change of Jakobshavn Isbrae, West Greenland:: 198519972007 JF - Journal of Glaciology Y1 - 2010 A1 - Roman J. Motyka A1 - Mark Fahnestock A1 - Martin Truffer VL - 56 UR - http://openurl.ingenta.com/content/xref?genre=article&issn=0022-1430&volume=56&issue=198&spage=635 ER - TY - JOUR T1 - Accurate ocean tide modeling in southeast Alaska and large tidal dissipation around Glacier Bay JF - Journal of oceanography Y1 - 2009 A1 - Inazu, D. A1 - Tatsuru Sato A1 - Miura, S. A1 - Ohta, Y. A1 - Nakamura, K. A1 - Fujimoto, H. A1 - Chris F. Larsen A1 - Higuchi, T. VL - 65 ER - TY - JOUR T1 - Calving icebergs indicate a thick layer of temperate ice at the base of Jakobshavn Isbræ, Greenland JF - Journal of Glaciology Y1 - 2009 A1 - M P Lüthi A1 - Mark Fahnestock A1 - Martin Truffer VL - 55 UR - http://openurl.ingenta.com/content/xref?genre=article&issn=0022-1430&volume=55&issue=191&spage=563 ER - TY - JOUR T1 - Changes of glaciers and climate in northwestern North America during the late twentieth century JF - Journal of Climate Y1 - 2009 A1 - Anthony A. Arendt A1 - Walsh, J. A1 - Harrison, W. VL - 22 ER - TY - JOUR T1 - Glacier changes in Alaska: can mass-balance models explain GRACE mascon trends? JF - Annals of Glaciology Y1 - 2009 A1 - Anthony A. Arendt A1 - Scott B Luthcke A1 - Regine Hock VL - 50 ER - TY - JOUR T1 - Implications for the dynamic health of a glacier from comparison of conventional and reference-surface balances JF - Annals of Glaciology Y1 - 2009 A1 - Harrison, W. A1 - Cox, LH A1 - Regine Hock A1 - March, RS A1 - Erin C Pettit VL - 50 ER - TY - JOUR T1 - Iterative methods for solving a nonlinear boundary inverse problem in glaciology JF - Journal of Inverse and Ill-posed Problems Y1 - 2009 A1 - Avdonin, S. A1 - Kozlov, V. A1 - Maxwell, D. A1 - Martin Truffer VL - 17 UR - http://www.reference-global.com/doi/abs/10.1515/JIIP.2 ER - TY - JOUR T1 - Mathematical modeling and numerical simulation of polythermal glaciers JF - J. Geophys. Res. Y1 - 2009 A1 - Andy Aschwanden A1 - Blatter, H. VL - 114 UR - http://www.agu.org/pubs/crossref/2009/2008JF001028.shtml ER - TY - JOUR T1 - A method to estimate the ice volume and ice-thickness distribution of alpine glaciers JF - Journal of Glaciology Y1 - 2009 A1 - Farinotti, D. A1 - Huss, M. A1 - Bauder, A. A1 - Funk, M. A1 - Martin Truffer VL - 55 UR - http://openurl.ingenta.com/content/xref?genre=article&issn=0022-1430&volume=55&issue=191&spage=422 ER - TY - JOUR T1 - Mountain glaciers and ice caps around Antarctica make a large sea-level rise contribution JF - Geophysical Research Letters Y1 - 2009 A1 - Regine Hock A1 - de Woul, M. A1 - Valentina Radić A1 - Dyurgerov, M. VL - 36 ER - TY - JOUR T1 - Shallow shelf approximation as a “sliding law” in a thermomechanically coupled ice sheet model JF - Journal of Geophysical Research Y1 - 2009 A1 - E. Bueler A1 - Brown, J. VL - 114 ER - TY - JOUR T1 - Terminus dynamics at an advancing glacier: Taku Glacier, Alaska JF - Journal of Glaciology Y1 - 2009 A1 - Martin Truffer A1 - Roman J. Motyka A1 - Hekkers, M. A1 - I M Howat A1 - King, M.A. VL - 55 UR - http://openurl.ingenta.com/content/xref?genre=article&issn=0022-1430&volume=55&issue=194&spage=1052 ER - TY - JOUR T1 - Testing longwave radiation parameterizations under clear and overcast skies at Storglaciären, Sweden JF - The Cryosphere Y1 - 2009 A1 - Sedlar, J. A1 - Regine Hock VL - 3 ER - TY - JOUR T1 - Analysis of scaling methods in deriving future volume evolutions of valley glaciers JF - Journal of Glaciology Y1 - 2008 A1 - Valentina Radić A1 - Regine Hock A1 - Oerlemans, J. VL - 54 ER - TY - JOUR T1 - Benchmark experiments for higher-order and full Stokes ice sheet models (ISMIP-HOM) JF - The Cryosphere Y1 - 2008 A1 - Frank Pattyn A1 - Perichon, L. A1 - Andy Aschwanden A1 - Breuer, B. A1 - de Smedt, B. A1 - Gagliardini, O. A1 - Gudmundsson, G. H. A1 - Hindmarsh, R. C. A. A1 - Hubbard, A. L. A1 - Jesse V Johnson A1 - Kleiner, T. A1 - Konovalov, Y. A1 - Martin, C. A1 - Payne, A. J. A1 - David Pollard A1 - Stephen F. Price A1 - M Rückamp A1 - Fuyuki Saito A1 - Souček, O. A1 - Sugiyama, S. A1 - Zwinger, T. VL - 2 ER - TY - JOUR T1 - Continued evolution of Jakobshavn Isbrae following its rapid speedup JF - J. geophys. Res Y1 - 2008 A1 - Ian Joughin A1 - I M Howat A1 - Mark Fahnestock A1 - B  E Smith A1 - Krabill, W. A1 - Alley, R.B. A1 - Stern, H. A1 - Martin Truffer VL - 113 UR - http://www.agu.org/pubs/crossref/2008/2008JF001023.shtml ER - TY - JOUR T1 - Correspondence: Another surge of Variegated Glacier, Alaska, USA, 2003/04 JF - Journal of Glaciology Y1 - 2008 A1 - Harrison, W. A1 - Roman J. Motyka A1 - Martin Truffer VL - 54 UR - http://www.ingentaconnect.com/content/igsoc/jog/2008/00000054/00000184/art00019 ER - TY - JOUR T1 - Determination of the seasonal mass balance of four Alpine glaciers since 1865 JF - J. Geophys. Res Y1 - 2008 A1 - Huss, M. A1 - Bauder, A. A1 - Funk, M. A1 - Regine Hock VL - 113 ER - TY - JOUR T1 - Distribution of snow accumulation on the Svartisen ice cap, Norway, assessed by a model of orographic precipitation JF - Hydrological Processes Y1 - 2008 A1 - Schuler, T.V. A1 - Crochet, P. A1 - Regine Hock A1 - Jackson, M. A1 - Barstad, I. A1 - Jóhannesson, T. VL - 22 ER - TY - JOUR T1 - Earth tides observed by gravity and GPS in southeastern Alaska JF - Journal of Geodynamics Y1 - 2008 A1 - Tatsuru Sato A1 - Miura, S. A1 - Ohta, Y. A1 - Fujimoto, H. A1 - Sun, W. A1 - Chris F. Larsen A1 - Heavner, M. A1 - Kaufman, AM A1 - Jeffrey T. Freymueller VL - 46 ER - TY - JOUR T1 - Glacier, fjord, and seismic response to recent large calving events, Jakobshavn Isbræ, Greenland JF - Geophysical Research Letters Y1 - 2008 A1 - Jason M Amundson A1 - Martin Truffer A1 - M P Lüthi A1 - Mark Fahnestock A1 - West, M. A1 - Roman J. Motyka VL - 35 UR - http://www.agu.org/pubs/crossref/2008/2008GL035281.shtml ER - TY - JOUR T1 - Glacier melt, air temperature, and energy balance in different climates: The Bolivian Tropics, the French Alps, and northern Sweden JF - J. Geophys. Res Y1 - 2008 A1 - Sicart, JE A1 - Regine Hock A1 - Six, D. VL - 113 ER - TY - JOUR T1 - Glacier Recession on Heard Island, Southern Indian Ocean JF - Arctic, Antarctic, and Alpine Research Y1 - 2008 A1 - Thost, D.E. A1 - Martin Truffer VL - 40 UR - http://www.bioone.org/doi/abs/10.1657/1523-0430(06-084)%5BTHOST%5D2.0.CO;2 ER - TY - JOUR T1 - Ice-front variation and tidewater behavior on Helheim and Kangerdlugssuaq Glaciers, Greenland JF - Journal of Geophysical Research: Earth Surface Y1 - 2008 A1 - Joughin, Ian A1 - Howat, Ian A1 - Alley, Richard B. A1 - Ekstrom, Goran A1 - Fahnestock, Mark A1 - Moon, Twila A1 - Nettles, Meredith A1 - Truffer, Martin A1 - Tsai, Victor C. AB - We used satellite images to examine the calving behavior ofHelheim and Kangerdlugssuaq Glaciers, Greenland, from 2001 to 2006, a period in which they retreated and speed up. These data show that many large iceberge-calving episodes coincided with teleseismically detected glacial erthquakes, suggesting that calving-related processes are the source of seismicity. For each of several events for which we hace observations, the ice front calved back to a large, pre-existing rift. These refits form where the ice has thinned to near flotation as the ice front retreats down back side of a bathymetric high, which agrees well with earlier theoretical predictions. In adition to recent retreat in a period of high temperature, analysis of several images shows that Helhaim retreated in the 20th Century during a warmer period and then re-adcanced during a subsequent cooler period. This apparent sensitivity to waming suggests that higher temperatures may promote an initial retread off a bathymetric high that is then sustained by tidewater dynamics as the ice front retreats into depper water. The cycle of frontal advance and retreat in less than a century indicates that tidewater glaciers in Greenland can advance rapidly. Greenland's larger resorvoir of inland ice and conditions that favor the formation of ice shelves likely contribute to the rapid rates of advance. VL - 113 SN - 0148-0227 UR - http://www.agu.org/pubs/crossref/2008/2007JF000837.shtml ER - TY - JOUR T1 - Ice-front variation and tidewater behavior on Helheim and Kangerdlugssuaq Glaciers, Greenland JF - Journal of Geophysical Research Y1 - 2008 A1 - Ian Joughin A1 - I M Howat A1 - Alley, R.B. A1 - Ekstrom, G. A1 - Mark Fahnestock A1 - Moon, T. A1 - Nettles, M. A1 - Martin Truffer A1 - Tsai, V.C. VL - 113 UR - http://www.agu.org/pubs/crossref/2008/2007JF000837.shtml ER - TY - JOUR T1 - Influence of snowpack layering on human-triggered snow slab avalanche release JF - Cold Regions Science and Technology Y1 - 2008 A1 - Habermann, M A1 - Schweizer, J A1 - Jamieson, B VL - 54 IS - 3 ER - TY - JOUR T1 - Internal accumulation on Storglaciaren, Sweden, in a multi-layer snow model coupled to a distributed energy-and mass-balance model JF - Journal of Glaciology Y1 - 2008 A1 - C H Reijmer A1 - Regine Hock VL - 54 ER - TY - JOUR T1 - An iterative scheme for determining glacier velocities and stresses JF - Journal of Glaciology Y1 - 2008 A1 - Maxwell, D. A1 - Martin Truffer A1 - Avdonin, S. A1 - Stuefer, M. VL - 54 UR - http://openurl.ingenta.com/content/xref?genre=article&issn=0022-1430&volume=54&issue=188&spage=888 ER - TY - JOUR T1 - Mass balance of the Greenland ice sheet from 1958 to 2007 JF - Geophysical Research Letters Y1 - 2008 A1 - Eric Rignot A1 - Box, J.E. A1 - Evan W. Burgess A1 - Hanna, E. VL - 35 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-58249086581&partnerID=40&md5=f29d2f8e4a2c1845220d5fc846c65f0a ER - TY - JOUR T1 - Recent glacier mass changes in the Gulf of Alaska region from GRACE mascon solutions JF - Journal of Glaciology Y1 - 2008 A1 - Scott B Luthcke A1 - Anthony A. Arendt A1 - Rowlands, D.D. A1 - J J McCarthy A1 - Chris F. Larsen VL - 54 ER - TY - JOUR T1 - Seasonal fluctuations in the advance of a tidewater glacier and potential causes: Hubbard Glacier, Alaska, USA JF - Journal of Glaciology Y1 - 2008 A1 - Ritchie, J.B. A1 - C S Lingle A1 - Roman J. Motyka A1 - Martin Truffer VL - 54 UR - http://openurl.ingenta.com/content/xref?genre=article&issn=0022-1430&volume=54&issue=186&spage=401 ER - TY - JOUR T1 - Seasonality of snow accumulation at Mount Wrangell, Alaska, USA JF - Journal of Glaciology Y1 - 2008 A1 - Kanamori, S. A1 - Benson, C.S. A1 - Martin Truffer A1 - Matoba, S. A1 - Solie, D.J. A1 - Shiraiwa, T. VL - 54 UR - http://www.ingentaconnect.com/content/igsoc/jog/2008/00000054/00000185/art00008 ER - TY - JOUR T1 - Climate sensitivity of Storglaciaren, Sweden: an intercomparison of mass-balance models using ERA-40 re-analysis and regional climate model data JF - Annals of glaciology Y1 - 2007 A1 - Regine Hock A1 - Valentina Radić A1 - de Woul, M. VL - 46 ER - TY - CONF T1 - Comparison of remote sensing derived glacier facies maps with distributed mass balance modelling at Engabreen, northern Norway. T2 - Proceedings of a workshop on Andean Glaciology and a symposium on the Contribution from Glaciers and Snow Cover to Runoff from Mountains in Different Climates during the 7th Scientific Assembly of the IAHS, Foz do Iguacu, Brazil, 4-9 April 2005. Y1 - 2007 A1 - M Braun A1 - Schuler, T.V. A1 - Regine Hock A1 - Brown, I. A1 - Jackson, M. A1 - Ginot, P. A1 - Sicart, JE A1 - others JF - Proceedings of a workshop on Andean Glaciology and a symposium on the Contribution from Glaciers and Snow Cover to Runoff from Mountains in Different Climates during the 7th Scientific Assembly of the IAHS, Foz do Iguacu, Brazil, 4-9 April 2005. PB - IAHS Press ER - TY - CONF T1 - Deriving glacier mass balance from accumulation area ratio on Storglaciären, Sweden. T2 - Proceedings of a workshop on Andean Glaciology and a symposium on the Contribution from Glaciers and Snow Cover to Runoff from Mountains in Different Climates during the 7th Scientific Assembly of the IAHS, Foz do Iguacu, Brazil, 4-9 April 2005. Y1 - 2007 A1 - Regine Hock A1 - Kootstra, D.S. A1 - C H Reijmer A1 - Ginot, P. A1 - Sicart, JE A1 - others JF - Proceedings of a workshop on Andean Glaciology and a symposium on the Contribution from Glaciers and Snow Cover to Runoff from Mountains in Different Climates during the 7th Scientific Assembly of the IAHS, Foz do Iguacu, Brazil, 4-9 April 2005. PB - IAHS Press ER - TY - JOUR T1 - Exact solutions to the thermomechanically coupled shallow-ice approximation: effective tools for verification JF - Journal of Glaciology Y1 - 2007 A1 - E. Bueler A1 - Brown, J. A1 - C S Lingle VL - 53 ER - TY - JOUR T1 - Fast computation of a viscoelastic deformable Earth model for ice-sheet simulations JF - Annals of Glaciology Y1 - 2007 A1 - E. Bueler A1 - C S Lingle A1 - Brown, J. VL - 46 ER - TY - JOUR T1 - Flotation and retreat of a lake-calving terminus, Mendenhall Glacier, southeast Alaska, USA JF - Journal of Glaciology Y1 - 2007 A1 - Boyce, E.S. A1 - Roman J. Motyka A1 - Martin Truffer VL - 53 ER - TY - JOUR T1 - Glacier changes in southeast Alaska and northwest British Columbia and contribution to sea level rise JF - J. Geophys. Res Y1 - 2007 A1 - Chris F. Larsen A1 - Roman J. Motyka A1 - Anthony A. Arendt A1 - Echelmeyer, K.A. A1 - Geissler, P.E. VL - 112 ER - TY - JOUR T1 - Glacier-dammed lake outburst events of Gornersee, Switzerland JF - Journal of Glaciology Y1 - 2007 A1 - Huss, M. A1 - Bauder, A. A1 - Werder, M. A1 - Funk, M. A1 - Regine Hock VL - 53 ER - TY - JOUR T1 - Glaciervolcano interactions in the North Crater of Mt Wrangell, Alaska JF - Annals of Glaciology Y1 - 2007 A1 - Benson, C.S. A1 - Roman J. Motyka A1 - McNUTT, S. A1 - M P Lüthi A1 - Martin Truffer VL - 45 ER - TY - JOUR T1 - Hubbard Glacier, Alaska: 2002 closure and outburst of Russell Fjord and postflood conditions at Gilbert Point JF - Journal of geophysical research Y1 - 2007 A1 - Roman J. Motyka A1 - Martin Truffer VL - 112 ER - TY - JOUR T1 - Meteorological observations and energy balance at Storglaciären, northern Sweden JF - IAH Publ Y1 - 2007 A1 - Konya, K. A1 - Regine Hock A1 - Naruse, R. VL - 318 ER - TY - JOUR T1 - Ocean acoustic effects of explosions on land: Evaluation of Cook Inlet beluga whale habitability JF - The Journal of the Acoustical Society of America Y1 - 2007 A1 - Tremblay, Sara K A1 - Anderson, Thomas S A1 - Pettit, Erin C A1 - Scheifele, Peter M A1 - Potty, Gopu R A1 - Miller, James H PB - Acoustical Society of America VL - 122 ER - TY - JOUR T1 - Post Little Ice Age Glacial Rebound in Glacier Bay National Park and Surrounding Areas JF - Alaska Park Science Y1 - 2007 A1 - Roman J. Motyka A1 - Chris F. Larsen A1 - Jeffrey T. Freymueller A1 - Echelmeyer, K.A. VL - 6 ER - TY - JOUR T1 - Rethinking ice sheet time scales JF - Science Y1 - 2007 A1 - Martin Truffer A1 - Mark Fahnestock VL - 315 ER - TY - JOUR T1 - The role of crystal fabric in flow near an ice divide JF - Journal of Glaciology Y1 - 2007 A1 - Erin C Pettit A1 - Thorsteinsson, Throstur A1 - Jacobson, H Paul A1 - Waddington, Edwin D PB - International Glaciological Society VL - 53 ER - TY - JOUR T1 - Volumearea scaling vs flowline modelling in glacier volume projections JF - Annals of Glaciology Y1 - 2007 A1 - Valentina Radić A1 - Regine Hock A1 - Oerlemans, J. VL - 46 ER - TY - JOUR T1 - Episodic reactivation of large-scale push moraines in front of the advancing Taku Glacier, Alaska JF - J. Geophys. Res. Y1 - 2006 A1 - Kuriger, Elsbeth Maria A1 - Truffer, M. A1 - Motyka, Roman J. A1 - Bucki, Adam K. VL - 111 UR - http://www.agu.org/pubs/crossref/2006/2005JF000385.shtml ER - TY - JOUR T1 - Ice Flow at Low Deviatoric Stress: Siple Dome, West Antarctica JF - Glacier Science and Environmental Change Y1 - 2006 A1 - Erin C Pettit PB - Wiley Online Library ER - TY - JOUR T1 - In situ measurements of till deformation and water pressure JF - J. Glaciol. Y1 - 2006 A1 - Truffer, M. A1 - Harrison, W.D. VL - 52 UR - http://openurl.ingenta.com/content/xref?genre=article{&}issn=0022-1430{&}volume=52{&}issue=177{&}spage=175 ER - TY - JOUR T1 - Rapid erosion of soft sediments by tidewater glacier advance: Taku Glacier, Alaska, USA JF - Geophys. Res. Lett. Y1 - 2006 A1 - Motyka, Roman J. A1 - Truffer, M. A1 - Kuriger, Elsbeth Maria A1 - Bucki, Adam K. VL - 33 UR - http://www.agu.org/pubs/crossref/2006/2006GL028467.shtml ER - TY - JOUR T1 - Time-dependent basal stress conditions beneath Black Rapids Glacier, Alaska, USA, inferred from measurements of ice deformation and surface motion JF - J. Glaciol. Y1 - 2006 A1 - Amundson, J. M. A1 - Truffer, M. A1 - Lüthi, Martin P. VL - 52 UR - http://openurl.ingenta.com/content/xref?genre=article{&}issn=0022-1430{&}volume=52{&}issue=178{&}spage=347 ER - TY - JOUR T1 - Candidate drill site near the Ross-Amundsen ice divide, West Antarctica JF - DRAFT, Mar Y1 - 2005 A1 - Conway, H A1 - Neumann, TA A1 - Stephen F. Price A1 - Waddington, ED A1 - Morse, D A1 - Taylor, K A1 - Mayewski, PA A1 - Dixon, D A1 - Erin C Pettit A1 - Steig, EJ ER - TY - JOUR T1 - Exact solutions and numerical verification for isothermal ice sheets JF - J. Glaciol. Y1 - 2005 A1 - E. Bueler A1 - C. S. Lingle A1 - J. A. Kallen-Brown A1 - D. N. Covey A1 - L. N. Bowman VL - 51 UR - http://www.ingentaconnect.com/content/igsoc/jog/2005/00000051/00000173/art00011 ER - TY - JOUR T1 - Meltwater production due to strain heating in Storglaciären, Sweden JF - J. Geophys. Res. Y1 - 2005 A1 - Andy Aschwanden A1 - Blatter, H. KW - glacier KW - polythermal KW - strain heating VL - 110 UR - http://www.agu.org/pubs/crossref/2005/2005JF000328.shtml ER - TY - JOUR T1 - Proposed drill site near the Ross–Amundsen ice divide, West Antarctica JF - White Paper for the US Ice Core Working Group Y1 - 2005 A1 - Conway, H A1 - Neumann, TA A1 - Stephen F. Price A1 - Waddington, ED A1 - Morse, D A1 - Taylor, K A1 - Mayewski, PA A1 - Dixon, D A1 - Erin C Pettit A1 - Steig, EJ ER - TY - JOUR T1 - Record negative glacier balances and low velocities during the 2004 heatwave in Alaska, USA: implications for the interpretation of observations by Zwally and others in Greenland JF - Journal of Glaciology Y1 - 2005 A1 - Truffer, Martin A1 - Harrison, W.D. A1 - March, R.S. VL - 51 UR - http://openurl.ingenta.com/content/xref?genre=article{&}issn=0022-1430{&}volume=51{&}issue=175{&}spage=663 https://www.cambridge.org/core/product/identifier/S002214300021085X/type/journal{\_}article ER - TY - JOUR T1 - The basal speed of valley glaciers: an inverse approach JF - J. Glaciol. Y1 - 2004 A1 - Truffer, M. VL - 50 UR - http://openurl.ingenta.com/content/xref?genre=article{&}issn=0022-1430{&}volume=50{&}issue=169{&}spage=236 ER - TY - JOUR T1 - Depth-and time-dependent vertical strain rates at Siple Dome, Antarctica JF - Journal of Glaciology Y1 - 2004 A1 - Elsberg, Daniel H A1 - Harrison, William D A1 - Zumberge, Mark A A1 - Morack, John L A1 - Erin C Pettit A1 - Waddington, Edward D A1 - Husmann, Eric PB - International Glaciological Society VL - 50 ER - TY - JOUR T1 - Large fluctuations in speed on Greenland's Jakobshavn Isbrae glacier. JF - Nature Y1 - 2004 A1 - Joughin, Ian A1 - Abdalati, Waleed A1 - Fahnestock, Mark AB - It is important to understand recent changes in the velocity of Greenland glaciers because the mass balance of the Greenland Ice Sheet is partly determined by the flow rates of these outlets. Jakobshavn Isbrae is Greenland's largest outlet glacier, draining about 6.5 per cent of the ice-sheet area, and it has been surveyed repeatedly since 1991 (ref. 2). Here we use remote sensing data to measure the velocity of Jakobshavn Isbrae between 1992 and 2003. We detect large variability of the velocity over time, including a slowing down from 6,700 m yr(-1) in 1985 to 5,700 m yr(-1) in 1992, and a subsequent speeding up to 9,400 m yr(-1) by 2000 and 12,600 m yr(-1) in 2003. These changes are consistent with earlier evidence for thickening of the glacier in the early 1990s and rapid thinning thereafter. Our observations indicate that fast-flowing glaciers can significantly alter ice discharge at sub-decadal timescales, with at least a potential to respond rapidly to a changing climate. VL - 432 SN - 0028-0836 ER - TY - JOUR T1 - Probing the till beneath Black Rapids Glacier, Alaska, USA JF - J. Glaciol. Y1 - 2004 A1 - Harrison, W.D. A1 - Truffer, M. A1 - Echelmeyer, K. A. A1 - Pomraning, D. A. A1 - Abnett, K. A. A1 - Ruhkick, R. H. VL - 50 UR - http://openurl.ingenta.com/content/xref?genre=article{&}issn=0022-1430{&}volume=50{&}issue=171{&}spage=608 ER - TY - JOUR T1 - Effects of basal sliding on isochrones and flow near an ice divide JF - Annals of Glaciology Y1 - 2003 A1 - Erin C Pettit A1 - Jacobson, H Paul A1 - Waddington, Edwin D PB - International Glaciological Society VL - 37 ER - TY - JOUR T1 - Ice flow at low deviatoric stress JF - Journal of Glaciology Y1 - 2003 A1 - Erin C Pettit A1 - Waddington, Edwin D PB - International Glaciological Society VL - 49 ER - TY - JOUR T1 - Of isbræ and ice streams JF - Ann. Glaciol. Y1 - 2003 A1 - Truffer, M. A1 - Echelmeyer, K. A. VL - 36 ER - TY - JOUR T1 - Spatial relationships between snow contaminant content, grain size, and surface temperature from multispectral images of Mt. Rainier, Washington (USA) JF - Remote sensing of environment Y1 - 2003 A1 - Kay, Jennifer E A1 - Gillespie, Alan R A1 - Hansen, Gary B A1 - Erin C Pettit PB - Elsevier VL - 86 ER - TY - JOUR T1 - A surface motion survey of Black Rapids Glacier, Alaska, U.S.A. JF - Ann. Glaciol. Y1 - 2003 A1 - Fatland, Dennis R. A1 - Lingle, Craig S. A1 - Truffer, M. VL - 36 UR - http://openurl.ingenta.com/content/xref?genre=article{&}issn=0260-3055{&}volume=36{&}issue=1{&}spage=29 ER - TY - JOUR T1 - Unique dynamic behaviors of ice divides: Siple Dome and the rheological properties of ice JF - PhD Dissertation Y1 - 2003 A1 - Erin C Pettit ER - TY - JOUR T1 - Measurement of vertical strain and velocity at Siple Dome, Antarctica, with optical sensors JF - Journal of Glaciology Y1 - 2002 A1 - Zumberge, Mark A A1 - Elsberg, Daniel H A1 - Harrison, William D A1 - Husmann, Eric A1 - Morack, John L A1 - Erin C Pettit A1 - Waddington, Edwin D PB - International Glaciological Society VL - 48 ER - TY - JOUR T1 - Mechanisms of fast flow in Jakobshavns Isbræ, Greenland, Part III: Measurements of ice deformation, temperature and cross-borehole conductivity in boreholes to the bedrock JF - J. Glaciol. Y1 - 2002 A1 - Lüthi, Martin P. A1 - Funk, M. A1 - Iken, A. A1 - Truffer, M. A1 - Gogineni, S. VL - 48 UR - http://openurl.ingenta.com/content/xref?genre=article{&}issn=0022-1430{&}volume=48{&}issue=162{&}spage=369 ER - TY - JOUR T1 - High geothermal heat flow, Basal melt, and the origin of rapid ice flow in central Greenland. JF - Science (New York, N.Y.) Y1 - 2001 A1 - Fahnestock, M A1 - Abdalati, W A1 - Joughin, Ian A1 - Brozena, J A1 - Gogineni, P AB - Age-depth relations from internal layering reveal a large region of rapid basal melting in Greenland. Melt is localized at the onset of rapid ice flow in the large ice stream that drains north off the summit dome and other areas in the northeast quadrant of the ice sheet. Locally, high melt rates indicate geothermal fluxes 15 to 30 times continental background. The southern limit of melt coincides with magnetic anomalies and topography that suggest a volcanic origin. VL - 294 UR - http://www.ncbi.nlm.nih.gov/pubmed/11743197 ER - TY - JOUR T1 - Implications of till deformation on glacier dynamics JF - J. Glaciol. Y1 - 2001 A1 - Truffer, M. A1 - Echelmeyer, K. A. A1 - Harrison, W.D. VL - 47 UR - http://openurl.ingenta.com/content/xref?genre=article{&}issn=0022-1430{&}volume=47{&}issue=156{&}spage=123 ER - TY - JOUR T1 - Glacier motion dominated by processes deep in underlying till JF - J. Glaciol. Y1 - 2000 A1 - Truffer, M. A1 - Harrison, W.D. A1 - Echelmeyer, K. A. VL - 46 UR - http://openurl.ingenta.com/content/xref?genre=article{&}issn=0022-1430{&}volume=46{&}issue=153{&}spage=213 ER - TY - JOUR T1 - Analysis of spectroscopic properties of erbium doped Ta 2 O 5–Al 2 O 3–SiO 2 optical fiber JF - Journal of non-crystalline solids Y1 - 1999 A1 - Oh, Kyunghwan A1 - Pettit, Erin A1 - Kilian, A A1 - Morse, TF PB - North-Holland VL - 259 ER - TY - JOUR T1 - Analysis of spectroscopic properties of erbium doped Ta 2 O 5–Al 2 O 3–SiO 2 optical fiber JF - Journal of non-crystalline solids Y1 - 1999 A1 - Oh, Kyunghwan Pettit, Erin A1 - Kilian, A A1 - Morse, TF PB - North-Holland VL - 259 ER - TY - JOUR T1 - Analysis of spectroscopic properties of erbium doped Ta 2 O 5–Al 2 O 3–SiO 2 optical fiber JF - Journal of non-crystalline solids Y1 - 1999 A1 - Oh, Kyunghwan A1 - Kilian, A A1 - Morse, TF PB - North-Holland VL - 259 ER - TY - JOUR T1 - Analysis of spectroscopic properties of erbium doped Ta< sub> 2 O< sub> 5–Al< sub> 2 O< sub> 3–SiO< sub> 2 optical fiber JF - Journal of non-crystalline solids Y1 - 1999 A1 - Oh, Kyunghwan A1 - Kilian, A A1 - Morse, TF PB - Elsevier VL - 259 ER - TY - JOUR T1 - Subglacial drilling at Black Rapids Glacier, Alaska, U.S.A : drilling method and sample descriptions JF - J. Glaciol. Y1 - 1999 A1 - Truffer, M. A1 - Motyka, Roman J. A1 - Harrison, W.D. A1 - Echelmeyer, K. A. A1 - Fisk, B. A1 - Tulaczyk, S. VL - 45 ER - TY - JOUR T1 - Thermal effects on the excited state absorption and upconversion process of erbium ions in germanosilicate optical fiber JF - Journal of non-crystalline solids Y1 - 1999 A1 - Pettit, Erin A1 - Simpson, Jay A1 - Oh, Kyunghwan A1 - Morse, TF PB - Elsevier VL - 259 ER - TY - JOUR T1 - Thermal effects on the excited state absorption and upconversion process of erbium ions in germanosilicate optical fiber JF - Journal of non-crystalline solids Y1 - 1999 A1 - Oh, Kyunghwan A1 - Morse, TF PB - Elsevier VL - 259 ER - TY - JOUR T1 - The sliding velocity over a sinusoidal bed at high water pressure JF - Journal of Glaciology Y1 - 1998 A1 - Truffer, Martin A1 - Iken, Almut VL - 44 ER - TY - JOUR T1 - The effects of APU characteristics on the design of hybrid control strategies for hybrid electric vehicles JF - PROGRESS IN TECHNOLOGY Y1 - 1997 A1 - Anderson, Catherine A1 - Erin C Pettit PB - SAE INTERNATIONAL VL - 58 ER - TY - JOUR T1 - The relationship between subglacial water pressure and velocity of Findelengletscher, Switzerland, during its advance and retreat} volume = {43 JF - Journal of Glaciology Y1 - 1997 A1 - Iken, A. A1 - Truffer, M. AB - Findelengletscher, Switzerland, advanced about 250 m between 1979$\backslash$nand 1985, and retreated thereafter. Subglacial water pressure, surface$\backslash$nvelocity and surface strain rate were determined at several sites.$\backslash$nThe measurements were made early in the melt seasons of 1980, 1982,$\backslash$n1985 and 1994 and in the autumn of 1983 and the winter of 1984. Changes$\backslash$nof surface geometry were assessed from aerial photographs. The estimated$\backslash$nbasal shear stress changed little between 1982 and 1994. Nevertheless,$\backslash$nlarge changes in the relationship of subglacial water pressure and$\backslash$nsurface velocity were observed, which cannot be reconciled with the$\backslash$nmost commonly used sliding law unless it is modified substantially$\backslash$nConsideration of possible reasons indicates that a change in the$\backslash$nsubglacial drainage system occurred, probably involving a change$\backslash$nin the degree of cavity interconnection. Isolated cavities damp the$\backslash$nvariations in sliding velocity that normally result from changes$\backslash$nin water pressure, because the pressure in isolated cavities decreases$\backslash$nas the sliding speed increases. In contrast, by transmitting water-pressure$\backslash$nfluctuations to a larger area of the bed, interconnected cavities$\backslash$namplify the effect of water-pressure fluctuations on sliding speed.$\backslash$nThus, we suggest that an observed decrease in velocity (for a given$\backslash$nwater pressure) between 1982 and 1994 was a consequence of a decrease$\backslash$nin the interconnectedness of the subglacial cavity system. SN - 0022-1430 ER - TY - JOUR T1 - Mechanical and hydrologic basis for the rapid motion of a large tidewater glacier: 2. Interpretation JF - Journal of Geophysical Research Y1 - 1994 A1 - Kamb, Barclay A1 - Engelhardt, Hermann A1 - Fahnestock, Mark A. A1 - Humphrey, Neil A1 - Meier, Mark A1 - Stone, Dan VL - 99 UR - http://www.agu.org/pubs/crossref/1994/94JB00467.shtml http://doi.wiley.com/10.1029/94JB00467 ER - TY - JOUR T1 - Assessing streamflow sensitivity to variations in glacier mass balance Y1 - 0 A1 - O’Neel, Shad A1 - Hood, Eran A1 - Arendt, Anthony A1 - Sass, Louis VL - 123 UR - http://link.springer.com/10.1007/s10584-013-1042-7 ER - TY - JOUR T1 - Glaciers and Climate of the Upper Susitna Basin, Alaska Y1 - 0 A1 - Bliss, Andrew A1 - Hock, Regine A1 - Wolken, Gabriel A1 - Whorton, Erin A1 - Aubry-Wake, Caroline A1 - Braun, Juliana A1 - Gusmeroli, Alessio A1 - Harrison, Will A1 - Hoffman, Andrew A1 - Liljedahl, Anna A1 - others ER - TY - JOUR T1 - Hazard assessment of the Tidal Inlet landslide and potential subsequent tsunami, Glacier Bay National Park, Alaska JF - Landslides Y1 - 0 A1 - Wieczorek, Gerald A1 - Geist, Eric A1 - Roman J. Motyka A1 - Jakob, Matthias AB - An unstable rock slump, estimated at 5 to 10 × 106 m3, lies perched above the northern shore of Tidal Inlet in Glacier Bay National Park, Alaska. This landslide mass has the potential to rapidly move into Tidal Inlet and generate large, long-period-impulse tsunami waves. Field and photographic examination revealed that the landslide moved between 1892 and 1919 after the retreat of the Little Ice Age glaciers from Tidal Inlet in 1890. Global positioning system measurements over a 2-year period show that the perched mass is presently moving at 3–4 cm annually indicating the landslide remains unstable. Numerical simulations of landslide-generated waves suggest that in the western arm of Glacier Bay, wave amplitudes would be greatest near the mouth of Tidal Inlet and slightly decrease with water depth according to Green’s law. As a function of time, wave amplitude would be greatest within approximately 40 min of the landslide entering water, with significant wave activity continuing for potentially several hours. VL - 4 UR - http://www.ingentaconnect.com/content/klu/10346/2007/00000004/00000003/00000084 ER - TY - JOUR T1 - Hubbard Glacier update: another closure of Russell Fiord in the making? JF - Journal of Glaciology Y1 - 0 A1 - Roman J. Motyka A1 - Lawson, Daniel A1 - Finnegan, David A1 - Kalli, George A1 - Molnia, Bruce A1 - Anthony A. Arendt VL - 54 UR - http://www.ingentaconnect.com/content/igsoc/jog/2008/00000054/00000186/art00020 ER -