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 - 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 - 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 - 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 - 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 -