Articles | Volume 18, issue 11
https://doi.org/10.5194/tc-18-4971-2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/tc-18-4971-2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
06 Nov 2024
Research article |
| 06 Nov 2024
| 06 Nov 2024
Thwaites Glacier thins and retreats fastest where ice-shelf channels intersect its grounding zone
Allison M. Chartrand
CORRESPONDING AUTHOR
Earth System Science Interdisciplinary Center, University of Maryland, College Park, MD, USA
NASA Goddard Space Flight Center, Greenbelt, MD, USA
Ian M. Howat
Byrd Polar and Climate Research Center, Ohio State University, Columbus, OH, USA
Ian R. Joughin
Applied Physics Laboratory, University of Washington, Seattle, WA, USA
Benjamin E. Smith
Applied Physics Laboratory, University of Washington, Seattle, WA, USA
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Andrew O. Hoffman, Knut Christianson, Ching-Yao Lai, Ian Joughin, Nicholas Holschuh, Elizabeth Case, Jonathan Kingslake, and the GHOST science team
The Cryosphere, 19, 1353–1372, https://doi.org/10.5194/tc-19-1353-2025, https://doi.org/10.5194/tc-19-1353-2025, 2025
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We use satellite and ice-penetrating radar technology to segment crevasses in the Amundsen Sea Embayment. Inspection of satellite time series reveals inland expansion of crevasses where surface stresses have increased. We develop a simple model for the strength of densifying snow and show that these crevasses are likely restricted to the near surface. This result bridges discrepancies between satellite and lab experiments and reveals the importance of porosity on surface crevasse formation.
Benjamin E. Smith, Michael Studinger, Tyler Sutterley, Zachary Fair, and Thomas Neumann
The Cryosphere, 19, 975–995, https://doi.org/10.5194/tc-19-975-2025, https://doi.org/10.5194/tc-19-975-2025, 2025
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This study investigates errors (biases) that may result when green lasers are used to measure the elevation of glaciers and ice sheets. These biases are important because if the snow or ice on top of the ice sheet changes, it can make the elevation of the ice appear to change by the wrong amount. We measure these biases over the Greenland Ice Sheet with a laser system on an airplane and explore how the use of satellite data can let us correct for the biases.
Grace P. Gjerde, Mark D. Behn, Laura A. Stevens, Sarah B. Das, and Ian R. Joughin
EGUsphere, https://doi.org/10.5194/egusphere-2024-3700, https://doi.org/10.5194/egusphere-2024-3700, 2025
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We characterize the magnitude and variability of transient speed-ups across a GPS array in western Greenland in 2011 and 2012. While we find no relationship between speed-up and runoff, late-season events have larger speed-up amplitudes and more spatially uniform patterns of speed-up across the GPS array compared to early season events. These results reflect an evolution toward a less efficient drainage system late in the melt season, with a pervasive system of open surface-to-bed conduits.
Twila A. Moon, Benjamin Cohen, Taryn E. Black, Kristin L. Laidre, Harry L. Stern, and Ian Joughin
The Cryosphere, 18, 4845–4872, https://doi.org/10.5194/tc-18-4845-2024, https://doi.org/10.5194/tc-18-4845-2024, 2024
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The complex geomorphology of southeast Greenland (SEG) creates dynamic fjord habitats for top marine predators, featuring glacier-derived floating ice, pack and landfast sea ice, and freshwater flux. We study the physical environment of SEG fjords, focusing on surface ice conditions, to provide a regional characterization that supports biological research. As Arctic warming persists, SEG may serve as a long-term refugium for ice-dependent wildlife due to the persistence of regional ice sheets.
Michael Studinger, Benjamin E. Smith, Nathan Kurtz, Alek Petty, Tyler Sutterley, and Rachel Tilling
The Cryosphere, 18, 2625–2652, https://doi.org/10.5194/tc-18-2625-2024, https://doi.org/10.5194/tc-18-2625-2024, 2024
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We use green lidar data and natural-color imagery over sea ice to quantify elevation biases potentially impacting estimates of change in ice thickness of the polar regions. We complement our analysis using a model of scattering of light in snow and ice that predicts the shape of lidar waveforms reflecting from snow and ice surfaces based on the shape of the transmitted pulse. We find that biased elevations exist in airborne and spaceborne data products from green lidars.
Ian Joughin, Daniel Shapero, and Pierre Dutrieux
The Cryosphere, 18, 2583–2601, https://doi.org/10.5194/tc-18-2583-2024, https://doi.org/10.5194/tc-18-2583-2024, 2024
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The Pine Island and Thwaites glaciers are losing ice to the ocean rapidly as warmer water melts their floating ice shelves. Models help determine how much such glaciers will contribute to sea level. We find that ice loss varies in response to how much melting the ice shelves are subjected to. Our estimated losses are also sensitive to how much the friction beneath the glaciers is reduced as it goes afloat. Melt-forced sea level rise from these glaciers is likely to be less than 10 cm by 2300.
Inès N. Otosaka, Andrew Shepherd, Erik R. Ivins, Nicole-Jeanne Schlegel, Charles Amory, Michiel R. van den Broeke, Martin Horwath, Ian Joughin, Michalea D. King, Gerhard Krinner, Sophie Nowicki, Anthony J. Payne, Eric Rignot, Ted Scambos, Karen M. Simon, Benjamin E. Smith, Louise S. Sørensen, Isabella Velicogna, Pippa L. Whitehouse, Geruo A, Cécile Agosta, Andreas P. Ahlstrøm, Alejandro Blazquez, William Colgan, Marcus E. Engdahl, Xavier Fettweis, Rene Forsberg, Hubert Gallée, Alex Gardner, Lin Gilbert, Noel Gourmelen, Andreas Groh, Brian C. Gunter, Christopher Harig, Veit Helm, Shfaqat Abbas Khan, Christoph Kittel, Hannes Konrad, Peter L. Langen, Benoit S. Lecavalier, Chia-Chun Liang, Bryant D. Loomis, Malcolm McMillan, Daniele Melini, Sebastian H. Mernild, Ruth Mottram, Jeremie Mouginot, Johan Nilsson, Brice Noël, Mark E. Pattle, William R. Peltier, Nadege Pie, Mònica Roca, Ingo Sasgen, Himanshu V. Save, Ki-Weon Seo, Bernd Scheuchl, Ernst J. O. Schrama, Ludwig Schröder, Sebastian B. Simonsen, Thomas Slater, Giorgio Spada, Tyler C. Sutterley, Bramha Dutt Vishwakarma, Jan Melchior van Wessem, David Wiese, Wouter van der Wal, and Bert Wouters
Earth Syst. Sci. Data, 15, 1597–1616, https://doi.org/10.5194/essd-15-1597-2023, https://doi.org/10.5194/essd-15-1597-2023, 2023
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By measuring changes in the volume, gravitational attraction, and ice flow of Greenland and Antarctica from space, we can monitor their mass gain and loss over time. Here, we present a new record of the Earth’s polar ice sheet mass balance produced by aggregating 50 satellite-based estimates of ice sheet mass change. This new assessment shows that the ice sheets have lost (7.5 x 1012) t of ice between 1992 and 2020, contributing 21 mm to sea level rise.
Benjamin E. Smith, Brooke Medley, Xavier Fettweis, Tyler Sutterley, Patrick Alexander, David Porter, and Marco Tedesco
The Cryosphere, 17, 789–808, https://doi.org/10.5194/tc-17-789-2023, https://doi.org/10.5194/tc-17-789-2023, 2023
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We use repeated satellite measurements of the height of the Greenland ice sheet to learn about how three computational models of snowfall, melt, and snow compaction represent actual changes in the ice sheet. We find that the models do a good job of estimating how the parts of the ice sheet near the coast have changed but that two of the models have trouble representing surface melt for the highest part of the ice sheet. This work provides suggestions for how to better model snowmelt.
Taryn E. Black and Ian Joughin
The Cryosphere, 17, 1–13, https://doi.org/10.5194/tc-17-1-2023, https://doi.org/10.5194/tc-17-1-2023, 2023
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The frontal positions of most ice-sheet-based glaciers in Greenland vary seasonally. On average, these glaciers begin retreating in May and begin advancing in October, and the difference between their most advanced and most retreated positions is 220 m. The timing may be related to the timing of melt on the ice sheet, and the seasonal length variation may be related to glacier speed. These seasonal variations can affect glacier behavior and, consequently, how much ice is lost from the ice sheet.
Brooke Medley, Thomas A. Neumann, H. Jay Zwally, Benjamin E. Smith, and C. Max Stevens
The Cryosphere, 16, 3971–4011, https://doi.org/10.5194/tc-16-3971-2022, https://doi.org/10.5194/tc-16-3971-2022, 2022
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Satellite altimeters measure the height or volume change over Earth's ice sheets, but in order to understand how that change translates into ice mass, we must account for various processes at the surface. Specifically, snowfall events generate large, transient increases in surface height, yet snow fall has a relatively low density, which means much of that height change is composed of air. This air signal must be removed from the observed height changes before we can assess ice mass change.
Sophie Goliber, Taryn Black, Ginny Catania, James M. Lea, Helene Olsen, Daniel Cheng, Suzanne Bevan, Anders Bjørk, Charlie Bunce, Stephen Brough, J. Rachel Carr, Tom Cowton, Alex Gardner, Dominik Fahrner, Emily Hill, Ian Joughin, Niels J. Korsgaard, Adrian Luckman, Twila Moon, Tavi Murray, Andrew Sole, Michael Wood, and Enze Zhang
The Cryosphere, 16, 3215–3233, https://doi.org/10.5194/tc-16-3215-2022, https://doi.org/10.5194/tc-16-3215-2022, 2022
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Terminus traces have been used to understand how Greenland's glaciers have changed over time; however, manual digitization is time-intensive, and a lack of coordination leads to duplication of efforts. We have compiled a dataset of over 39 000 terminus traces for 278 glaciers for scientific and machine learning applications. We also provide an overview of an updated version of the Google Earth Engine Digitization Tool (GEEDiT), which has been developed specifically for the Greenland Ice Sheet.
Qi Liang, Wanxin Xiao, Ian Howat, Xiao Cheng, Fengming Hui, Zhuoqi Chen, Mi Jiang, and Lei Zheng
The Cryosphere, 16, 2671–2681, https://doi.org/10.5194/tc-16-2671-2022, https://doi.org/10.5194/tc-16-2671-2022, 2022
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Using multi-temporal ArcticDEM and ICESat-2 altimetry data, we document changes in surface elevation of a subglacial lake basin from 2012 to 2021. The long-term measurements show that the subglacial lake was recharged by surface meltwater and that a rapid drainage event in late August 2019 induced an abrupt ice velocity change. Multiple factors regulate the episodic filling and drainage of the lake. Our study also reveals ~ 64 % of the surface meltwater successfully descended to the bed.
Taryn E. Black and Ian Joughin
The Cryosphere, 16, 807–824, https://doi.org/10.5194/tc-16-807-2022, https://doi.org/10.5194/tc-16-807-2022, 2022
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We used satellite images to create a comprehensive record of annual glacier change in northwest Greenland from 1972 through 2021. We found that nearly all glaciers in our study area have retreated and glacier retreat accelerated from around 1996. Comparing these results with climate data, we found that glacier retreat is most sensitive to water runoff and moderately sensitive to ocean temperatures. These can affect glacier fronts in several ways, so no process clearly dominates glacier retreat.
Andrew O. Hoffman, Knut Christianson, Daniel Shapero, Benjamin E. Smith, and Ian Joughin
The Cryosphere, 14, 4603–4609, https://doi.org/10.5194/tc-14-4603-2020, https://doi.org/10.5194/tc-14-4603-2020, 2020
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The West Antarctic Ice Sheet has long been considered geometrically prone to collapse, and Thwaites Glacier, the largest glacier in the Amundsen Sea, is likely in the early stages of disintegration. Using observations of Thwaites Glacier velocity and elevation change, we show that the transport of ~2 km3 of water beneath Thwaites Glacier has only a small and transient effect on glacier speed relative to ongoing thinning driven by ocean melt.
Cited articles
Adusumilli, S., Fricker, H. A., Medley, B., Padman, L., and Siegfried, M. R.: Interannual variations in meltwater input to the Southern Ocean from Antarctic ice shelves, Nat. Geosci., 13, 616–620, https://doi.org/10.1038/s41561-020-0616-z, 2020.
Alley, K. E., Scambos, T. A., Siegfried, M. R., and Fricker, H. A.: Impacts of warm water on Antarctic ice shelf stability through basal channel formation, Nat. Geosci., 9, 290–293, https://doi.org/10.1038/ngeo2675, 2016.
Alley, K. E., Scambos, T. A., Alley, R. B., and Holschuh, N.: Troughs developed in ice-stream shear margins precondition ice shelves for ocean-driven breakup, Science Advances, 5, eaax2215, https://doi.org/10.1126/sciadv.aax2215, 2019.
Bevan, S. L., Luckman, A. J., Benn, D. I., Adusumilli, S., and Crawford, A.: Brief communication: Thwaites Glacier cavity evolution, The Cryosphere, 15, 3317–3328, https://doi.org/10.5194/tc-15-3317-2021, 2021.
Blair, J. B. and Hofton, M.: IceBridge LVIS-GH L2 Geolocated Surface Elevation Product, ILVGH2, Version 1, NASA National Snow and Ice Data Center Distributed Active Archive Center [data set], https://doi.org/10.5067/RELPCEXB0MY3, 2015.
Blankenship, D. D., Kempf, S. D., Young, D. A., Roberts, J. L., van Ommen, T., Forsberg, R., Siegert, M. J., Palmer, S. J., and Dowdeswell, J. A.: IceBridge Riegl Laser Altimeter L2 Geolocated Surface Elevation Triplets, ILUTP2, Version 1, NASA National Snow and Ice Data Center Distributed Active Archive Center [data set], https://doi.org/10.5067/JV9DENETK13E, 2012.
Bradley, A. T. and Hewitt, I. J.: Tipping point in ice-sheet grounding-zone melting due to ocean water intrusion, Nat. Geosci., 17, 631–637, https://doi.org/10.1038/s41561-024-01465-7, 2024.
Chartrand, A.: Thwaites Glacier thins and retreats fastest where ice-shelf channels intersect its grounding zone, dataset+code, Zenodo [code and data set], https://doi.org/10.5281/zenodo.13667120, 2024.
Chartrand, A. M. and Howat, I. M.: Basal Channel Evolution on the Getz Ice Shelf, West Antarctica, J. Geophys. Res.-Earth, 125, e2019JF005293, https://doi.org/10.1029/2019JF005293, 2020.
Chartrand, A. M. and Howat, I. M.: A comparison of contemporaneous airborne altimetry and ice-thickness measurements of Antarctic ice shelves, J. Glaciol., 1–14, https://doi.org/10.1017/jog.2023.49, 2023.
Ciracì, E., Rignot, E., Scheuchl, B., Tolpekin, V., Wollersheim, M., An, L., Milillo, P., Bueso-Bello, J.-L., Rizzoli, P., and Dini, L.: Melt rates in the kilometer-size grounding zone of Petermann Glacier, Greenland, before and during a retreat, P. Natl. Acad. Sci. USA, 120, e2220924120, https://doi.org/10.1073/pnas.2220924120, 2023.
dos Santos, T. D., Barnes, J. M., Goldberg, D. N., Gudmundsson, G. H., and Morlighem, M.: Drivers of Change of Thwaites Glacier, West Antarctica, Between 1995 and 2015, Geophys. Res. Lett., 48, e2021GL093102, https://doi.org/10.1029/2021GL093102, 2021.
Dotto, T. S., Heywood, K. J., Hall, R. A., Scambos, T. A., Zheng, Y., Nakayama, Y., Hyogo, S., Snow, T., Wåhlin, A. K., Wild, C., Truffer, M., Muto, A., Alley, K. E., Boehme, L., Bortolotto, G. A., Tyler, S. W., and Pettit, E.: Ocean variability beneath Thwaites Eastern Ice Shelf driven by the Pine Island Bay Gyre strength, Nat. Commun., 13, 7840, https://doi.org/10.1038/s41467-022-35499-5, 2022.
Dow, C. F., Lee, W. S., Greenbaum, J. S., Greene, C. A., Blankenship, D. D., Poinar, K., Forrest, A. L., Young, D. A., and Zappa, C. J.: Basal channels drive active surface hydrology and transverse ice shelf fracture, Science Advances, 4, eaao7212, https://doi.org/10.1126/sciadv.aao7212, 2018.
Drews, R.: Evolution of ice-shelf channels in Antarctic ice shelves, The Cryosphere, 9, 1169–1181, https://doi.org/10.5194/tc-9-1169-2015, 2015.
Drews, R., Pattyn, F., Hewitt, I. J., Ng, F. S. L., Berger, S., Matsuoka, K., Helm, V., Bergeot, N., Favier, L., and Neckel, N.: Actively evolving subglacial conduits and eskers initiate ice shelf channels at an Antarctic grounding line, Nat. Commun., 8, 1–10, https://doi.org/10.1038/ncomms15228, 2017.
Dutrieux, P., De Rydt, J., Jenkins, A., Holland, P. R., Ha, H. K., Lee, S. H., Steig, E. J., Ding, Q., Abrahamsen, E. P., and Schröder, M.: Strong Sensitivity of Pine Island Ice-Shelf Melting to Climatic Variability, Science, 343, 174–178, https://doi.org/10.1126/science.1244341, 2014.
European Space Agency: L1b NOP-IOP-GOP SAR, Version Baseline C, European Space Agency [data set], https://doi.org/10.5270/CR2-gsyvnx0, 2023.
Förste, C., Bruinsma, S. L., Abrikosov, O., Lemoine, J.-M., Marty, J. C., Flechtner, F., Balmino, G., Barthelmes, F., and Biancale, R.: EIGEN-6C4 The latest combined global gravity field model including GOCE data up to degree and order 2190 of GFZ Potsdam and GRGS Toulouse, ICGEM [data set], https://doi.org/10.5880/ICGEM.2015.1, 2014.
Fricker, H. A., Coleman, R., Padman, L., Scambos, T. A., Bohlander, J., and Brunt, K. M.: Mapping the grounding zone of the Amery Ice Shelf, East Antarctica using InSAR, MODIS and ICESat, Antarct. Sci., 21, 515–532, https://doi.org/10.1017/S095410200999023X, 2009.
Gillet-Chaulet, F., Durand, G., Gagliardini, O., Mosbeux, C., Mouginot, J., Rémy, F., and Ritz, C.: Assimilation of surface velocities acquired between 1996 and 2010 to constrain the form of the basal friction law under Pine Island Glacier, Geophys. Res. Lett., 43, 10311–10321, https://doi.org/10.1002/2016GL069937, 2016.
Goldberg, D. N., Heimbach, P., Joughin, I., and Smith, B.: Committed retreat of Smith, Pope, and Kohler Glaciers over the next 30 years inferred by transient model calibration, The Cryosphere, 9, 2429–2446, https://doi.org/10.5194/tc-9-2429-2015, 2015.
Gourmelen, N., Goldberg, D. N., Snow, K., Henley, S. F., Bingham, R. G., Kimura, S., Hogg, A. E., Shepherd, A., Mouginot, J., Lenaerts, J. T. M., Ligtenberg, S. R. M., and van de Berg, W. J.: Channelized Melting Drives Thinning Under a Rapidly Melting Antarctic Ice Shelf, Geophys. Res. Lett., 44, 9796–9804, https://doi.org/10.1002/2017GL074929, 2017.
Gudmundsson, G. H., Krug, J., Durand, G., Favier, L., and Gagliardini, O.: The stability of grounding lines on retrograde slopes, The Cryosphere, 6, 1497–1505, https://doi.org/10.5194/tc-6-1497-2012, 2012.
Hager, A. O., Hoffman, M. J., Price, S. F., and Schroeder, D. M.: Persistent, extensive channelized drainage modeled beneath Thwaites Glacier, West Antarctica, The Cryosphere, 16, 3575–3599, https://doi.org/10.5194/tc-16-3575-2022, 2022.
Hoffman, M. J., Asay-Davis, X., Price, S. F., Fyke, J., and Perego, M.: Effect of Subshelf Melt Variability on Sea Level Rise Contribution From Thwaites Glacier, Antarctica, J. Geophys. Res.-Earth, 124, e2019JF005155, https://doi.org/10.1029/2019JF005155, 2019.
Hogan, K. A., Larter, R. D., Graham, A. G. C., Arthern, R., Kirkham, J. D., Totten, R. L., Jordan, T. A., Clark, R., Fitzgerald, V., Wåhlin, A. K., Anderson, J. B., Hillenbrand, C.-D., Nitsche, F. O., Simkins, L., Smith, J. A., Gohl, K., Arndt, J. E., Hong, J., and Wellner, J.: Revealing the former bed of Thwaites Glacier using sea-floor bathymetry: implications for warm-water routing and bed controls on ice flow and buttressing, The Cryosphere, 14, 2883–2908, https://doi.org/10.5194/tc-14-2883-2020, 2020.
Holland, P. R., Bevan, S. L., and Luckman, A. J.: Strong Ocean Melting Feedback During the Recent Retreat of Thwaites Glacier, Geophys. Res. Lett., 50, e2023GL103088, https://doi.org/10.1029/2023GL103088, 2023.
Howard, S. L., Erofeeva, S., and Padman, L.: CATS2008: Circum-Antarctic Tidal Simulation version 2008, U.S. Antarctic Program (USAP) Data Center [data set], https://doi.org/10.15784/601235, 2019.
Howat, I. M., Porter, C., Smith, B. E., Noh, M.-J., and Morin, P.: The Reference Elevation Model of Antarctica, The Cryosphere, 13, 665–674, https://doi.org/10.5194/tc-13-665-2019, 2019.
Howat, I., Porter, C., Noh, M.-J., Husby, E., Khuvis, S., Danish, E., Tomko, K., Gardiner, J., Negrete, A., Yadav, B., Klassen, J., Kelleher, C., Cloutier, M., Bakker, J., Enos, J., Arnold, G., Bauer, G., and Morin, P.: The Reference Elevation Model of Antarctica – Strips, Version 4.1, Harvard Dataverse [data set], https://doi.org/10.7910/DVN/X7NDNY, 2022a.
Howat, I., Porter, C., Noh, M.-J., Husby, E., Khuvis, S., Danish, E., Tomko, K., Gardiner, J., Negrete, A., Yadav, B., Klassen, J., Kelleher, C., Cloutier, M., Bakker, J., Enos, J., Arnold, G., Bauer, G., and Morin, P.: The Reference Elevation Model of Antarctica - Mosaics, Version 2, Harvard Dataverse [data set], https://doi.org/10.7910/DVN/EBW8UC, Harvard Dataverse, V1, 2022b.
Jenkins, A.: Convection-Driven Melting near the Grounding Lines of Ice Shelves and Tidewater Glaciers, J. Phys. Oceanogr., 41, 2279–2294, https://doi.org/10.1175/JPO-D-11-03.1, 2011.
Joughin, I., Tulaczyk, S., Bamber, J. L., Blankenship, D., Holt, J. W., Scambos, T., and Vaughan, D. G.: Basal conditions for Pine Island and Thwaites Glaciers, West Antarctica, determined using satellite and airborne data, J. Glaciol., 55, 245–257, https://doi.org/10.3189/002214309788608705, 2009.
Joughin, I., Smith, B. E., and Medley, B.: Marine Ice Sheet Collapse Potentially Under Way for the Thwaites Glacier Basin, West Antarctica, Science, 344, 735–738, https://doi.org/10.1126/science.1249055, 2014.
Joughin, I., Smith, B. E., and Schoof, C. G.: Regularized Coulomb Friction Laws for Ice Sheet Sliding: Application to Pine Island Glacier, Antarctica, Geophys. Res. Lett., 46, 4764–4771, https://doi.org/10.1029/2019GL082526, 2019.
Joughin, I., Shapero, D., and Dutrieux, P.: Responses of the Pine Island and Thwaites glaciers to melt and sliding parameterizations, The Cryosphere, 18, 2583–2601, https://doi.org/10.5194/tc-18-2583-2024, 2024.
Knudsen, P., Andersen, O., Maximenko, N., and Hafner, J.: A new combined mean dynamic topography model – DTUUH22MDT, European Space Agency Living Planet Symposium, Bonn, Germany, 23–27 May 2022, A10.02-66775, https://lps22.ollyservices.com/frontend/ (last access: 16 October 2024), 2022 (data available at: https://ftp.spacecenter.dk/pub/DTU22/MDT/, last access: 26 April 2023).
Le Brocq, A. M., Ross, N., Griggs, J. A., Bingham, R. G., Corr, H. F. J., Ferraccioli, F., Jenkins, A., Jordan, T. A., Payne, A. J., Rippin, D. M., and Siegert, M. J.: Evidence from ice shelves for channelized meltwater flow beneath the Antarctic Ice Sheet, Nat. Geosci., 6, 945–948, https://doi.org/10.1038/ngeo1977, 2013.
Ligtenberg, S. R. M., Helsen, M. M., and van den Broeke, M. R.: An improved semi-empirical model for the densification of Antarctic firn, The Cryosphere, 5, 809–819, https://doi.org/10.5194/tc-5-809-2011, 2011.
Miles, B. W. J., Stokes, C. R., Jenkins, A., Jordan, J. R., Jamieson, S. S. R., and Gudmundsson, G. H.: Intermittent structural weakening and acceleration of the Thwaites Glacier Tongue between 2000 and 2018, J. Glaciol., 66, 485–495, https://doi.org/10.1017/jog.2020.20, 2020.
Milillo, P., Rignot, E., Rizzoli, P., Scheuchl, B., Mouginot, J., Bueso-Bello, J., and Prats-Iraola, P.: Heterogeneous retreat and ice melt of Thwaites Glacier, West Antarctica, Science Advances, 5, eaau3433, https://doi.org/10.1126/sciadv.aau3433, 2019.
Millgate, T., Holland, P. R., Jenkins, A., and Johnson, H. L.: The effect of basal channels on oceanic ice-shelf melting, J. Geophys. Res.-Oceans, 118, 6951–6964, https://doi.org/10.1002/2013JC009402, 2013.
Morlighem, M.: MEaSUREs BedMachine Antarctica, NSIDC-0756, Version 3, NASA National Snow and Ice Data Center Distributed Active Archive Center [data set], https://doi.org/10.5067/FPSU0V1MWUB6, 2022.
Morlighem, M., Rignot, E., Binder, T., Blankenship, D., Drews, R., Eagles, G., Eisen, O., Ferraccioli, F., Forsberg, R., Fretwell, P., Goel, V., Greenbaum, J. S., Gudmundsson, H., Guo, J., Helm, V., Hofstede, C., Howat, I., Humbert, A., Jokat, W., Karlsson, N. B., Lee, W. S., Matsuoka, K., Millan, R., Mouginot, J., Paden, J., Pattyn, F., Roberts, J., Rosier, S., Ruppel, A., Seroussi, H., Smith, E. C., Steinhage, D., Sun, B., van den Broeke, M. R., van Ommen, T. D., van Wessem, M., and Young, D. A.: Deep glacial troughs and stabilizing ridges unveiled beneath the margins of the Antarctic ice sheet, Nat. Geosci., 13, 132–137, https://doi.org/10.1038/s41561-019-0510-8, 2020.
Mouginot, J., Scheuchl, B., and Rignot, E.: Mapping of Ice Motion in Antarctica Using Synthetic-Aperture Radar Data, Remote Sens.-Basel, 4, 2753–2767, https://doi.org/10.3390/rs4092753, 2012.
Mouginot, J., Scheuchl, B., and Rignot, E.: MEaSUREs Annual Antarctic Ice Velocity Maps, NSIDC-0720, Version 1, NASA National Snow and Ice Data Center Distributed Active Archive Center [data set], https://doi.org/10.5067/9T4EPQXTJYW9, 2017a.
Mouginot, J., Scheuchl, B., and Rignot, E.: MEaSUREs Antarctic Boundaries for IPY 2007–2009 from Satellite Radar, NSIDC-0709, Version 2, NASA National Snow and Ice Data Center Distributed Active Archive Center [data set], https://doi.org/10.5067/AXE4121732AD, 2017b.
Nakayama, Y., Menemenlis, D., Zhang, H., Schodlok, M., and Rignot, E.: Origin of Circumpolar Deep Water intruding onto the Amundsen and Bellingshausen Sea continental shelves, Nat. Commun., 9, 3403, https://doi.org/10.1038/s41467-018-05813-1, 2018.
Narkevic, A., Csatho, B., and Schenk, T.: Rapid Basal Channel Growth Beneath Greenland's Longest Floating Ice Shelf, Geophys. Res. Lett., 50, e2023GL103226, https://doi.org/10.1029/2023GL103226, 2023.
Neckel, N., Franke, S., Helm, V., Drews, R., and Jansen, D.: Evidence of Cascading Subglacial Water Flow at Jutulstraumen Glacier (Antarctica) Derived From Sentinel-1 and ICESat-2 Measurements, Geophys. Res. Lett., 48, e2021GL094472, https://doi.org/10.1029/2021GL094472, 2021.
Nuth, C. and Kääb, A.: Co-registration and bias corrections of satellite elevation data sets for quantifying glacier thickness change, The Cryosphere, 5, 271–290, https://doi.org/10.5194/tc-5-271-2011, 2011.
Paden, J., Li, J., Leuschen, C., Rodriguez-Morales, F., and Hale, R.: IceBridge MCoRDS L2 Ice Thickness, IRMCR2, Version 1, NASA National Snow and Ice Data Center Distributed Active Archive Center [data set], https://doi.org/10.5067/GDQ0CUCVTE2Q, 2010.
Paden, J. D., Li, J., Leuschen, Carl, Rodriguez-Morales, F., and Hale, R.: Pre-IceBridge MCoRDS L2 Ice Thickness, Version 1, NASA National Snow and Ice Data Center Distributed Active Archive Center [data set], https://doi.org/10.5067/QKMTQ02C2U56, 2011.
Padman, L., Siegfried, M. R., and Fricker, H. A.: Ocean Tide Influences on the Antarctic and Greenland Ice Sheets, Rev. Geophys., 56, 2016RG000546, https://doi.org/10.1002/2016RG000546, 2018.
Rignot, E., Mouginot, J., and Scheuchl, B.: Ice Flow of the Antarctic Ice Sheet, Science, 333, 1427–1430, https://doi.org/10.1126/science.1208336, 2011.
Rignot, E., Mouginot, J., Morlighem, M., Seroussi, H., and Scheuchl, B.: Widespread, rapid grounding line retreat of Pine Island, Thwaites, Smith, and Kohler glaciers, West Antarctica, from 1992 to 2011, Geophys. Res. Lett., 41, 3502–3509, https://doi.org/10.1002/2014GL060140, 2014.
Rignot, E., Mouginot, J., and Scheuchl, B.: MEaSUREs Antarctic Grounding Line from Differential Satellite Radar Interferometry, NSIDC-0498, Version 2, NASA National Snow and Ice Data Center Distributed Active Archive Center, [data set], https://doi.org/10.5067/IKBWW4RYHF1Q, 2016.
Rignot, E., Mouginot, J., and Scheuchl, B.: MEaSUREs InSAR-Based Antarctica Ice Velocity Map, NSIDC-0484, Version 2, NASA National Snow and Ice Data Center Distributed Active Archive Center [data set], https://doi.org/10.5067/D7GK8F5J8M8R, 2017.
Rignot, E., Mouginot, J., Scheuchl, B., van den Broeke, M., van Wessem, M. J., and Morlighem, M.: Four decades of Antarctic Ice Sheet mass balance from 1979–2017, P. Natl. Acad. Sci. USA, 116, 1095–1103, https://doi.org/10.1073/pnas.1812883116, 2019.
Rignot, E., Ciracì, E., Scheuchl, B., Tolpekin, V., Wollersheim, M., and Dow, C.: Widespread seawater intrusions beneath the grounded ice of Thwaites Glacier, West Antarctica, P. Natl. Acad. Sci. USA, 121, e2404766121, https://doi.org/10.1073/pnas.2404766121, 2024.
Schmidt, B. E., Washam, P., Davis, P. E. D., Nicholls, K. W., Holland, D. M., Lawrence, J. D., Riverman, K. L., Smith, J. A., Spears, A., Dichek, D. J. G., Mullen, A. D., Clyne, E., Yeager, B., Anker, P., Meister, M. R., Hurwitz, B. C., Quartini, E. S., Bryson, F. E., Basinski-Ferris, A., Thomas, C., Wake, J., Vaughan, D. G., Anandakrishnan, S., Rignot, E., Paden, J., and Makinson, K.: Heterogeneous melting near the Thwaites Glacier grounding line, Nature, 614, 471–478, https://doi.org/10.1038/s41586-022-05691-0, 2023.
Schoof, C.: Ice sheet grounding line dynamics: Steady states, stability, and hysteresis, J. Geophys. Res., 112, F03S28, https://doi.org/10.1029/2006JF000664, 2007.
Schwanghart, W. and Scherler, D.: Short Communication: TopoToolbox 2 – MATLAB-based software for topographic analysis and modeling in Earth surface sciences, Earth Surf. Dynam., 2, 1–7, https://doi.org/10.5194/esurf-2-1-2014, 2014.
Seroussi, H., Nakayama, Y., Larour, E., Menemenlis, D., Morlighem, M., Rignot, E., and Khazendar, A.: Continued retreat of Thwaites Glacier, West Antarctica, controlled by bed topography and ocean circulation, Geophys. Res. Lett., 44, 6191–6199, https://doi.org/10.1002/2017GL072910, 2017.
Shean, D. E., Joughin, I. R., Dutrieux, P., Smith, B. E., and Berthier, E.: Ice shelf basal melt rates from a high-resolution digital elevation model (DEM) record for Pine Island Glacier, Antarctica, The Cryosphere, 13, 2633–2656, https://doi.org/10.5194/tc-13-2633-2019, 2019.
Smith, B. E., Gourmelen, N., Huth, A., and Joughin, I.: Connected subglacial lake drainage beneath Thwaites Glacier, West Antarctica, The Cryosphere, 11, 451–467, https://doi.org/10.5194/tc-11-451-2017, 2017.
Smith, B., Adusumilli, S., Csathó, B. M., Felikson, D., Fricker, H. A., Gardner, A. S., Holschuh, N., Lee, J., Nilsson, J., Paolo, F., Siegfried, M. R., Sutterley, T., and the ICESat-2 Science Team: ATLAS/ICESat-2 L3A Land Ice Height, ATL06, Version 5, NASA National Snow and Ice Data Center Distributed Active Archive Center [data set], https://doi.org/10.5067/ATLAS/ATL06.005, 2021.
Smith, B., Adusumilli, S., Csathó, B. M., Felikson, D., Fricker, H. A., Gardner, A. S., Holschuh, N., Lee, J., Nilsson, J., Paolo, F., Siegfried, M. R., Sutterley, T., and the ICESat-2 Science Team: ATLAS/ICESat-2 L3A Land Ice Height, ATL06, Version 6, NASA National Snow and Ice Data Center Distributed Active Archive Center [data set], https://doi.org/10.5067/ATLAS/ATL06.006, 2023.
Stubblefield, A. G., Wearing, M. G., and Meyer, C. R.: Linear analysis of ice-shelf topography response to basal melting and freezing, P. Roy. Soc. A-Math. Phy., 479, 20230290, https://doi.org/10.1098/rspa.2023.0290, 2023.
Studinger, M.: IceBridge ATM L1B Elevation and Return Strength, ILATM1B, Version 2, NASA National Snow and Ice Data Center Distributed Active Archive Center [data set], https://doi.org/10.5067/19SIM5TXKPGT, 2013.
van Wessem, J. M., van de Berg, W. J., Noël, B. P. Y., van Meijgaard, E., Amory, C., Birnbaum, G., Jakobs, C. L., Krüger, K., Lenaerts, J. T. M., Lhermitte, S., Ligtenberg, S. R. M., Medley, B., Reijmer, C. H., van Tricht, K., Trusel, L. D., van Ulft, L. H., Wouters, B., Wuite, J., and van den Broeke, M. R.: Modelling the climate and surface mass balance of polar ice sheets using RACMO2 – Part 2: Antarctica (1979–2016), The Cryosphere, 12, 1479–1498, https://doi.org/10.5194/tc-12-1479-2018, 2018.
Vaughan, D. G., Corr, H. F. J., Bindschadler, R. A., Dutrieux, P., Gudmundsson, G. H., Jenkins, A., Newman, T., Vornberger, P., and Wingham, D. J.: Subglacial melt channels and fracture in the floating part of Pine Island Glacier, Antarctica, J. Geophys. Res., 117, F03012, https://doi.org/10.1029/2012JF002360, 2012.
Washam, P., Nicholls, K. W., Münchow, A., and Padman, L.: Summer surface melt thins Petermann Gletscher Ice Shelf by enhancing channelized basal melt, J. Glaciol., 65, 662–674, https://doi.org/10.1017/jog.2019.43, 2019.
Wearing, M. G., Stevens, L. A., Dutrieux, P., and Kingslake, J.: Ice-Shelf Basal Melt Channels Stabilized by Secondary Flow, Geophys. Res. Lett., 48, e2021GL094872, https://doi.org/10.1029/2021GL094872, 2021.
Weertman, J.: Stability of the Junction of an Ice Sheet and an Ice Shelf, J. Glaciol., 13, 3–11, https://doi.org/10.1017/S0022143000023327, 1974.
Wild, C. T., Alley, K. E., Muto, A., Truffer, M., Scambos, T. A., and Pettit, E. C.: Weakening of the pinning point buttressing Thwaites Glacier, West Antarctica, The Cryosphere, 16, 397–417, https://doi.org/10.5194/tc-16-397-2022, 2022.
Yu, H., Rignot, E., Seroussi, H., and Morlighem, M.: Retreat of Thwaites Glacier, West Antarctica, over the next 100 years using various ice flow models, ice shelf melt scenarios and basal friction laws, The Cryosphere, 12, 3861–3876, https://doi.org/10.5194/tc-12-3861-2018, 2018.
Zinck, A.-S. P., Wouters, B., Lambert, E., and Lhermitte, S.: Unveiling spatial variability within the Dotson Melt Channel through high-resolution basal melt rates from the Reference Elevation Model of Antarctica, The Cryosphere, 17, 3785–3801, https://doi.org/10.5194/tc-17-3785-2023, 2023.
Short summary
This study uses high-resolution remote-sensing data to show that shrinking of the West Antarctic Thwaites Glacier’s ice shelf (floating extension) is exacerbated by several sub-ice-shelf meltwater channels that form as the glacier transitions from full contact with the seafloor to fully floating. In mapping these channels, the position of the transition zone, and thinning rates of the Thwaites Glacier, this work elucidates important processes driving its rapid contribution to sea level rise.
This study uses high-resolution remote-sensing data to show that shrinking of the West Antarctic...
