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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 -