Articles | Volume 12, issue 8
https://doi.org/10.5194/tc-12-2707-2018
© Author(s) 2018. 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-12-2707-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
17 Aug 2018
Research article |
| 17 Aug 2018
| 17 Aug 2018
Diagnosing ice sheet grounding line stability from landform morphology
Department of Earth, Environmental, and Planetary Sciences, Rice
University, Houston, TX 77005, USA
Department of Environmental Sciences, University of Virginia,
Charlottesville, VA 22904, USA
Sarah L. Greenwood
Department of Geological Sciences, Stockholm University, 10691
Stockholm, Sweden
John B. Anderson
Department of Earth, Environmental, and Planetary Sciences, Rice
University, Houston, TX 77005, USA
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Allison P. Lepp, Lauren E. Miller, John B. Anderson, Matt O'Regan, Monica C. M. Winsborrow, James A. Smith, Claus-Dieter Hillenbrand, Julia S. Wellner, Lindsay O. Prothro, and Evgeny A. Podolskiy
The Cryosphere, 18, 2297–2319, https://doi.org/10.5194/tc-18-2297-2024, https://doi.org/10.5194/tc-18-2297-2024, 2024
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Shape and surface texture of silt-sized grains are measured to connect marine sediment records with subglacial water flow. We find that grain shape alteration is greatest in glaciers where high-energy drainage events and abundant melting of surface ice are inferred and that the surfaces of silt-sized sediments preserve evidence of glacial transport. Our results suggest grain shape and texture may reveal whether glaciers previously experienced temperate conditions with more abundant meltwater.
Marion A. McKenzie, Lauren E. Miller, Allison P. Lepp, and Regina DeWitt
Clim. Past, 20, 891–908, https://doi.org/10.5194/cp-20-891-2024, https://doi.org/10.5194/cp-20-891-2024, 2024
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Records of the interaction between land and glacial ice movement in the Puget Lowland of Washington State are used to interpret that solid Earth movement provided stability to this marine-terminating glacial ice for at least 500 years. These results are significant because this landscape is similar to parts of the Greenland Ice Sheet and the Antarctic Peninsula, indicating that the interactions seen in this area are applicable to modern glaciated regions.
Marion A. McKenzie, Lauren E. Miller, Jacob S. Slawson, Emma J. MacKie, and Shujie Wang
The Cryosphere, 17, 2477–2486, https://doi.org/10.5194/tc-17-2477-2023, https://doi.org/10.5194/tc-17-2477-2023, 2023
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Topographic highs (“bumps”) across glaciated landscapes have the potential to affect glacial ice. Bumps in the deglaciated Puget Lowland are assessed for streamlined glacial features to provide insight on ice–bed interactions. We identify a general threshold in which bumps significantly disrupt ice flow and sedimentary processes in this location. However, not all bumps have the same degree of impact. The system assessed here has relevance to parts of the Greenland Ice Sheet and Thwaites Glacier.
Kelly A. Hogan, Robert D. Larter, Alastair G. C. Graham, Robert Arthern, James D. Kirkham, Rebecca L. Totten, Tom A. Jordan, Rachel Clark, Victoria Fitzgerald, Anna K. Wåhlin, John B. Anderson, Claus-Dieter Hillenbrand, Frank O. Nitsche, Lauren Simkins, James A. Smith, Karsten Gohl, Jan Erik Arndt, Jongkuk Hong, and Julia Wellner
The Cryosphere, 14, 2883–2908, https://doi.org/10.5194/tc-14-2883-2020, https://doi.org/10.5194/tc-14-2883-2020, 2020
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The sea-floor geometry around the rapidly changing Thwaites Glacier is a key control on warm ocean waters reaching the ice shelf and grounding zone beyond. This area was previously unsurveyed due to icebergs and sea-ice cover. The International Thwaites Glacier Collaboration mapped this area for the first time in 2019. The data reveal troughs over 1200 m deep and, as this region is thought to have only ungrounded recently, provide key insights into the morphology beneath the grounded ice sheet.
Ewa Demianiuk, Mateusz Baca, Danijela Popović, Inès Barrenechea Angeles, Ngoc-Loi Nguyen, Jan Pawlowski, John B. Anderson, and Wojciech Majewski
Biogeosciences, 22, 2601–2620, https://doi.org/10.5194/bg-22-2601-2025, https://doi.org/10.5194/bg-22-2601-2025, 2025
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Ancient foraminiferal DNA is studied in five Antarctic cores with sediments up to 25 kyr old. We use a standard and a new, more effective marker, which may become the next standard for paleoenvironmental studies. Much less diverse foraminifera occur on slopes of submarine moraines than in open-marine settings. Soft-walled foraminifera, not found in the fossil record, are especially abundant. There is no foraminiferal DNA in tills, suggesting its destruction during glacial redeposition.
Allison P. Lepp, Lauren E. Miller, John B. Anderson, Matt O'Regan, Monica C. M. Winsborrow, James A. Smith, Claus-Dieter Hillenbrand, Julia S. Wellner, Lindsay O. Prothro, and Evgeny A. Podolskiy
The Cryosphere, 18, 2297–2319, https://doi.org/10.5194/tc-18-2297-2024, https://doi.org/10.5194/tc-18-2297-2024, 2024
Short summary
Short summary
Shape and surface texture of silt-sized grains are measured to connect marine sediment records with subglacial water flow. We find that grain shape alteration is greatest in glaciers where high-energy drainage events and abundant melting of surface ice are inferred and that the surfaces of silt-sized sediments preserve evidence of glacial transport. Our results suggest grain shape and texture may reveal whether glaciers previously experienced temperate conditions with more abundant meltwater.
Marion A. McKenzie, Lauren E. Miller, Allison P. Lepp, and Regina DeWitt
Clim. Past, 20, 891–908, https://doi.org/10.5194/cp-20-891-2024, https://doi.org/10.5194/cp-20-891-2024, 2024
Short summary
Short summary
Records of the interaction between land and glacial ice movement in the Puget Lowland of Washington State are used to interpret that solid Earth movement provided stability to this marine-terminating glacial ice for at least 500 years. These results are significant because this landscape is similar to parts of the Greenland Ice Sheet and the Antarctic Peninsula, indicating that the interactions seen in this area are applicable to modern glaciated regions.
Marion A. McKenzie, Lauren E. Miller, Jacob S. Slawson, Emma J. MacKie, and Shujie Wang
The Cryosphere, 17, 2477–2486, https://doi.org/10.5194/tc-17-2477-2023, https://doi.org/10.5194/tc-17-2477-2023, 2023
Short summary
Short summary
Topographic highs (“bumps”) across glaciated landscapes have the potential to affect glacial ice. Bumps in the deglaciated Puget Lowland are assessed for streamlined glacial features to provide insight on ice–bed interactions. We identify a general threshold in which bumps significantly disrupt ice flow and sedimentary processes in this location. However, not all bumps have the same degree of impact. The system assessed here has relevance to parts of the Greenland Ice Sheet and Thwaites Glacier.
Kelly A. Hogan, Robert D. Larter, Alastair G. C. Graham, Robert Arthern, James D. Kirkham, Rebecca L. Totten, Tom A. Jordan, Rachel Clark, Victoria Fitzgerald, Anna K. Wåhlin, John B. Anderson, Claus-Dieter Hillenbrand, Frank O. Nitsche, Lauren Simkins, James A. Smith, Karsten Gohl, Jan Erik Arndt, Jongkuk Hong, and Julia Wellner
The Cryosphere, 14, 2883–2908, https://doi.org/10.5194/tc-14-2883-2020, https://doi.org/10.5194/tc-14-2883-2020, 2020
Short summary
Short summary
The sea-floor geometry around the rapidly changing Thwaites Glacier is a key control on warm ocean waters reaching the ice shelf and grounding zone beyond. This area was previously unsurveyed due to icebergs and sea-ice cover. The International Thwaites Glacier Collaboration mapped this area for the first time in 2019. The data reveal troughs over 1200 m deep and, as this region is thought to have only ungrounded recently, provide key insights into the morphology beneath the grounded ice sheet.
Martin Jakobsson, Christian Stranne, Matt O'Regan, Sarah L. Greenwood, Bo Gustafsson, Christoph Humborg, and Elizabeth Weidner
Ocean Sci., 15, 905–924, https://doi.org/10.5194/os-15-905-2019, https://doi.org/10.5194/os-15-905-2019, 2019
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The bottom topography of the Baltic Sea is analysed using the digital depth model from the European Marine Observation and Data Network (EMODnet) published in 2018. Analyses include depth distribution vs. area and seafloor depth variation on a kilometre scale. The limits for the Baltic Sea and analysed sub-basins are from HELCOM. EMODnet is compared with the previously most widely used depth model and the area of deep water exchange between the Bothnian Sea and the Northern Baltic Proper.
Anna Ruth W. Halberstadt, Lauren M. Simkins, Sarah L. Greenwood, and John B. Anderson
The Cryosphere, 10, 1003–1020, https://doi.org/10.5194/tc-10-1003-2016, https://doi.org/10.5194/tc-10-1003-2016, 2016
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Geomorphic features on the Ross Sea sea floor provide a record of ice-sheet behaviour during the Last Glacial Maximum and subsequent retreat. Based on extensive mapping of these glacial landforms, a large embayment formed in the eastern Ross Sea. This was followed by complex, late-stage retreat in the western Ross Sea where banks stabilised the ice sheet. Physiography and sea floor geology act as regional controls on ice-sheet dynamics across the Ross Sea.
C. Lavoie, E. W. Domack, E. C. Pettit, T. A. Scambos, R. D. Larter, H.-W. Schenke, K. C. Yoo, J. Gutt, J. Wellner, M. Canals, J. B. Anderson, and D. Amblas
The Cryosphere, 9, 613–629, https://doi.org/10.5194/tc-9-613-2015, https://doi.org/10.5194/tc-9-613-2015, 2015
F. O. Nitsche, K. Gohl, R. D. Larter, C.-D. Hillenbrand, G. Kuhn, J. A. Smith, S. Jacobs, J. B. Anderson, and M. Jakobsson
The Cryosphere, 7, 249–262, https://doi.org/10.5194/tc-7-249-2013, https://doi.org/10.5194/tc-7-249-2013, 2013
Related subject area
Discipline: Ice sheets | Subject: Antarctic
A facet-based numerical model to retrieve ice sheet topography from Sentinel-3 altimetry
Current reversal leads to regime change in the Amery Ice Shelf cavity in the 21st century
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Changes in Antarctic surface conditions and potential for ice shelf hydrofracturing from 1850 to 2200
A reconstruction of the ice thickness of the Antarctic Peninsula Ice Sheet north of 70° S
Bathymetry-constrained impact of relative sea-level change on basal melting in Antarctica
Age–depth distribution in western Dronning Maud Land, East Antarctica, and Antarctic-wide comparisons of internal reflection horizons
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Thwaites Glacier thins and retreats fastest where ice-shelf channels intersect its grounding zone
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The influence of present-day regional surface mass balance uncertainties on the future evolution of the Antarctic Ice Sheet
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Hysteresis of idealized, instability-prone outlet glaciers in response to pinning-point buttressing variation
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Extensive palaeo-surfaces beneath the Evans–Rutford region of the West Antarctic Ice Sheet control modern and past ice flow
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Towards the systematic reconnaissance of seismic signals from glaciers and ice sheets – Part 2: Unsupervised learning for source process characterization
Geometric amplification and suppression of ice-shelf basal melt in West Antarctica
Viscoelastic mechanics of tidally induced lake drainage in the Amery grounding zone
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Jérémie Aublanc, François Boy, Franck Borde, and Pierre Féménias
The Cryosphere, 19, 1937–1954, https://doi.org/10.5194/tc-19-1937-2025, https://doi.org/10.5194/tc-19-1937-2025, 2025
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In this study we developed a novel processing chain to derive the ice sheet topography from Sentinel-3 altimetry measurements (named "AMPLI"). The major innovation lies in the use of numerical simulations to geolocate the radar impact point on the ground. The performance improvement is substantial compared to ground segment processing. Furthermore, with AMPLI we show that Sentinel-3 estimates the surface elevation change of the Antarctic ice sheet with a high level of agreement with ICESat-2.
Jing Jin, Antony J. Payne, and Christopher Y. S. Bull
The Cryosphere, 19, 1873–1896, https://doi.org/10.5194/tc-19-1873-2025, https://doi.org/10.5194/tc-19-1873-2025, 2025
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The Amery Ice Shelf cavity is one of the largest cold cavities filled by relatively cold Dense Shelf Water. However, in this study, we show that warm intrusion of modified Circumpolar Deep Water flushes the Amery cavity, which changes it from a cold cavity to a warm cavity and leads to an abrupt increase in the basal melt rate in the 2060s. The shift to a warm cavity is attributed to a freshening-driven current reversal in front of the ice shelf.
Heather L. Selley, Anna E. Hogg, Benjamin J. Davison, Pierre Dutrieux, and Thomas Slater
The Cryosphere, 19, 1725–1738, https://doi.org/10.5194/tc-19-1725-2025, https://doi.org/10.5194/tc-19-1725-2025, 2025
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We used satellite observations to measure recent changes in ice speed and flow direction in the Pope, Smith, and Kohler region of West Antarctica (2005–2022). We found substantial speed-up on seven ice streams of up to 87 %. However, Kohler West Glacier has slowed by 10 %, due to the redirection of ice flow into its rapidly thinning neighbour. This process of “ice piracy” has not previously been directly observed on this rapid timescale and may influence future ice shelf and sheet mass changes.
Nicolas C. Jourdain, Charles Amory, Christoph Kittel, and Gaël Durand
The Cryosphere, 19, 1641–1674, https://doi.org/10.5194/tc-19-1641-2025, https://doi.org/10.5194/tc-19-1641-2025, 2025
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A mixed statistical–physical approach is used to reproduce the behaviour of a regional climate model. From that, we estimate the contribution of snowfall and melting at the surface of the Antarctic Ice Sheet to changes in global mean sea level. We also investigate the impact of surface melting in a warmer climate on the stability of the Antarctic ice shelves that provide back stress on the ice flow to the ocean.
Kaian Shahateet, Johannes J. Fürst, Francisco Navarro, Thorsten Seehaus, Daniel Farinotti, and Matthias Braun
The Cryosphere, 19, 1577–1597, https://doi.org/10.5194/tc-19-1577-2025, https://doi.org/10.5194/tc-19-1577-2025, 2025
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In the present work, we provide a new ice thickness reconstruction of the Antarctic Peninsula Ice Sheet north of 70º S using inversion modeling. This model consists of two steps: the first uses basic assumptions of the rheology of the glacier, and the second uses mass conservation to improve the reconstruction where the assumptions made previously are expected to fail. Validation with independent data showed that our reconstruction improved compared to other reconstructions that are available.
Moritz Kreuzer, Torsten Albrecht, Lena Nicola, Ronja Reese, and Ricarda Winkelmann
The Cryosphere, 19, 1181–1203, https://doi.org/10.5194/tc-19-1181-2025, https://doi.org/10.5194/tc-19-1181-2025, 2025
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The study investigates how changing sea levels around Antarctica can potentially affect the melting of floating ice shelves. It utilizes numerical models for both the Antarctic Ice Sheet and the solid Earth, investigating features like troughs and sills that control the flow of ocean water onto the continental shelf. The research finds that compared to climatic changes, the effect of relative sea level on ice-shelf melting is small.
Steven Franke, Daniel Steinhage, Veit Helm, Alexandra M. Zuhr, Julien A. Bodart, Olaf Eisen, and Paul Bons
The Cryosphere, 19, 1153–1180, https://doi.org/10.5194/tc-19-1153-2025, https://doi.org/10.5194/tc-19-1153-2025, 2025
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The study presents internal reflection horizons (IRHs) over an area of 450 000 km² from western Dronning Maud Land, Antarctica, spanning 4.8–91 ka. Using radar and ice core data, nine IRHs were dated and correlated with volcanic events. The data enhance our understanding of the ice sheet's age–depth architecture, accumulation, and dynamics. The findings inform ice flow models and contribute to Antarctic-wide comparisons of IRHs, supporting efforts toward a 3D age–depth ice sheet model.
Lawrence A. Bird, Felicity S. McCormack, Johanna Beckmann, Richard S. Jones, and Andrew N. Mackintosh
The Cryosphere, 19, 955–973, https://doi.org/10.5194/tc-19-955-2025, https://doi.org/10.5194/tc-19-955-2025, 2025
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Vanderford Glacier is the fastest-retreating glacier in East Antarctica and may have important implications for future ice loss from the Aurora Subglacial Basin. Our ice sheet model simulations suggest that grounding line retreat is driven by sub-ice-shelf basal melting, in which warm ocean waters melt ice close to the grounding line. We show that current estimates of basal melt are likely too low, highlighting the need for improved estimates and direct measurements of basal melt in the region.
Benoit S. Lecavalier and Lev Tarasov
The Cryosphere, 19, 919–953, https://doi.org/10.5194/tc-19-919-2025, https://doi.org/10.5194/tc-19-919-2025, 2025
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We present the evolution of the Antarctic Ice Sheet (AIS) over the last 200 kyr by means of a history-matching analysis where an updated observational database constrained ~ 10 000 model simulations. During peak glaciation at the Last Glacial Maximum (LGM), the best-fitting sub-ensemble of AIS simulations reached an excess grounded ice volume relative to the present of 9.2 to 26.5 m equivalent sea level relative to the present. The LGM AIS volume can help resolve the LGM missing-ice problem.
Lawrence A. Bird, Vitaliy Ogarko, Laurent Ailleres, Lachlan Grose, Jeremie Giraud, Felicity S. McCormack, David E. Gwyther, Jason L. Roberts, Richard S. Jones, and Andrew N. Mackintosh
EGUsphere, https://doi.org/10.5194/egusphere-2025-211, https://doi.org/10.5194/egusphere-2025-211, 2025
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The terrain of the seafloor has important controls on the access of warm water to below floating ice shelves around Antarctica. Here, we present an open-source method to infer what the seafloor looks like around the Antarctic continent, and within these ice shelf cavities, using measurements of the Earth’s gravitational field. We present an improved seafloor map for the Vincennes Bay region in East Antarctica and assess its impact on ice melt rates.
James F. O'Neill, Tamsin L. Edwards, Daniel F. Martin, Courtney Shafer, Stephen L. Cornford, Hélène L. Seroussi, Sophie Nowicki, Mira Adhikari, and Lauren J. Gregoire
The Cryosphere, 19, 541–563, https://doi.org/10.5194/tc-19-541-2025, https://doi.org/10.5194/tc-19-541-2025, 2025
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We use an ice sheet model to simulate the Antarctic contribution to sea level over the 21st century under a range of future climates and varying how sensitive the ice sheet is to different processes. We find that ocean temperatures increase and more snow falls on the ice sheet under stronger warming scenarios. When the ice sheet is sensitive to ocean warming, ocean melt-driven loss exceeds snowfall-driven gains, meaning that the sea level contribution is greater with more climate warming.
Joanne S. Johnson, John Woodward, Ian Nesbitt, Kate Winter, Seth Campbell, Keir A. Nichols, Ryan A. Venturelli, Scott Braddock, Brent M. Goehring, Brenda Hall, Dylan H. Rood, and Greg Balco
The Cryosphere, 19, 303–324, https://doi.org/10.5194/tc-19-303-2025, https://doi.org/10.5194/tc-19-303-2025, 2025
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Determining where and when the Antarctic ice sheet was smaller than present requires recovery and exposure dating of subglacial bedrock. Here we use ice sheet model outputs and field data (geological and glaciological observations, bedrock samples, and ground-penetrating radar) to assess the suitability for subglacial drilling of sites in the Hudson Mountains, West Antarctica. We find that no sites are perfect, but two are feasible, with the most suitable being Winkie Nunatak (74.86°S, 99.77°W).
Francesca Baldacchino, Nicholas R. Golledge, Mathieu Morlighem, Huw Horgan, Alanna V. Alevropoulos-Borrill, Alena Malyarenko, Alexandra Gossart, Daniel P. Lowry, and Laurine van Haastrecht
The Cryosphere, 19, 107–127, https://doi.org/10.5194/tc-19-107-2025, https://doi.org/10.5194/tc-19-107-2025, 2025
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Understanding how the Ross Ice Shelf flow is changing in a warming world is important for predicting ice sheet change. Field measurements show clear intra-annual variations in ice flow; however, it is unclear what mechanisms drive this variability. We show that local perturbations in basal melt can have a significant impact on ice flow speed, but a combination of forcings is likely driving the observed variability in ice flow.
Elise Kazmierczak, Thomas Gregov, Violaine Coulon, and Frank Pattyn
The Cryosphere, 18, 5887–5911, https://doi.org/10.5194/tc-18-5887-2024, https://doi.org/10.5194/tc-18-5887-2024, 2024
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We introduce a new fast model for water flow beneath the ice sheet capable of handling various hydrological and bed conditions in a unified way. Applying this model to Thwaites Glacier, we show that accounting for this water flow in ice sheet model projections has the potential to greatly increase the contribution to future sea level rise. We also demonstrate that the sensitivity of the ice sheet in response to external changes depends on the efficiency of the drainage and the bed type.
Matthias O. Willen, Bert Wouters, Taco Broerse, Eric Buchta, and Veit Helm
EGUsphere, https://doi.org/10.5194/egusphere-2024-3086, https://doi.org/10.5194/egusphere-2024-3086, 2024
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Collapse of the West Antarctic ice sheet in the Amundsen Sea Embayment is likely in the near future. Vertical uplift of bedrock due to glacial isostatic adjustment stabilizes the ice sheet and may delay its collapse. So far, only spatially and temporally sparse GNSS measurements have been able to observe this bedrock motion. We have combined satellite data and quantified a region-wide bedrock motion that independently matches GNSS measurements. This can improve ice-sheet predictions.
Erica Margaret Lucas, Natalya Gomez, and Terry Wilson
EGUsphere, https://doi.org/10.5194/egusphere-2024-2957, https://doi.org/10.5194/egusphere-2024-2957, 2024
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We investigate the effects of incorporating regional-scale lateral variability (~50–100 km) in upper mantle structure into models of Earth deformation and sea level change associated with ice mass changes in West Antarctica. Regional-scale variability in upper mantle structure is found to impact relative sea level and crustal rate predictions for modern (last ~25–125 years) and projected (next ~300 years) ice mass changes, especially in coastal regions that undergo rapid ice mass loss.
Allison M. Chartrand, Ian M. Howat, Ian R. Joughin, and Benjamin E. Smith
The Cryosphere, 18, 4971–4992, https://doi.org/10.5194/tc-18-4971-2024, https://doi.org/10.5194/tc-18-4971-2024, 2024
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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.
Brad Reed, J. A. Mattias Green, Adrian Jenkins, and G. Hilmar Gudmundsson
The Cryosphere, 18, 4567–4587, https://doi.org/10.5194/tc-18-4567-2024, https://doi.org/10.5194/tc-18-4567-2024, 2024
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We use a numerical ice-flow model to simulate the response of a 1940s Pine Island Glacier to changes in melting beneath its ice shelf. A decadal period of warm forcing is sufficient to push the glacier into an unstable, irreversible retreat from its long-term position on a subglacial ridge to an upstream ice plain. This retreat can only be stopped when unrealistic cold forcing is applied. These results show that short warm anomalies can lead to quick and substantial increases in ice flux.
Tianming Ma, Zhuang Jiang, Minghu Ding, Pengzhen He, Yuansheng Li, Wenqian Zhang, and Lei Geng
The Cryosphere, 18, 4547–4565, https://doi.org/10.5194/tc-18-4547-2024, https://doi.org/10.5194/tc-18-4547-2024, 2024
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We constructed a box model to evaluate the isotope effects of atmosphere–snow water vapor exchange at Dome A, Antarctica. The results show clear and invisible diurnal changes in surface snow isotopes under summer and winter conditions, respectively. The model also predicts that the annual net effects of atmosphere–snow water vapor exchange would be overall enrichments in snow isotopes since the effects in summer appear to be greater than those in winter at the study site.
Robert G. Bingham, Julien A. Bodart, Marie G. P. Cavitte, Ailsa Chung, Rebecca J. Sanderson, Johannes C. R. Sutter, Olaf Eisen, Nanna B. Karlsson, Joseph A. MacGregor, Neil Ross, Duncan A. Young, David W. Ashmore, Andreas Born, Winnie Chu, Xiangbin Cui, Reinhard Drews, Steven Franke, Vikram Goel, John W. Goodge, A. Clara J. Henry, Antoine Hermant, Benjamin H. Hills, Nicholas Holschuh, Michelle R. Koutnik, Gwendolyn J.-M. C. Leysinger Vieli, Emma J. Mackie, Elisa Mantelli, Carlos Martín, Felix S. L. Ng, Falk M. Oraschewski, Felipe Napoleoni, Frédéric Parrenin, Sergey V. Popov, Therese Rieckh, Rebecca Schlegel, Dustin M. Schroeder, Martin J. Siegert, Xueyuan Tang, Thomas O. Teisberg, Kate Winter, Shuai Yan, Harry Davis, Christine F. Dow, Tyler J. Fudge, Tom A. Jordan, Bernd Kulessa, Kenichi Matsuoka, Clara J. Nyqvist, Maryam Rahnemoonfar, Matthew R. Siegfried, Shivangini Singh, Verjan Višnjević, Rodrigo Zamora, and Alexandra Zuhr
EGUsphere, https://doi.org/10.5194/egusphere-2024-2593, https://doi.org/10.5194/egusphere-2024-2593, 2024
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The ice sheets covering Antarctica have built up over millenia through successive snowfall events which become buried and preserved as internal surfaces of equal age detectable with ice-penetrating radar. This paper describes an international initiative to work together on this archival data to build a comprehensive 3-D picture of how old the ice is everywhere across Antarctica, and how this will be used to reconstruct past and predict future ice and climate behaviour.
Ann Kristin Klose, Violaine Coulon, Frank Pattyn, and Ricarda Winkelmann
The Cryosphere, 18, 4463–4492, https://doi.org/10.5194/tc-18-4463-2024, https://doi.org/10.5194/tc-18-4463-2024, 2024
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We systematically assess the long-term sea-level response from Antarctica to warming projected over the next centuries, using two ice-sheet models. We show that this committed Antarctic sea-level contribution is substantially higher than the transient sea-level change projected for the coming decades. A low-emission scenario already poses considerable risk of multi-meter sea-level increase over the next millennia, while additional East Antarctic ice loss unfolds under the high-emission pathway.
Christian Wirths, Thomas F. Stocker, and Johannes C. R. Sutter
The Cryosphere, 18, 4435–4462, https://doi.org/10.5194/tc-18-4435-2024, https://doi.org/10.5194/tc-18-4435-2024, 2024
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We investigated the influence of several regional climate models on the Antarctic Ice Sheet when applied as forcing for the Parallel Ice Sheet Model (PISM). Our study shows that the choice of regional climate model forcing results in uncertainties of around a tenth of those in future sea level rise projections and also affects the extent of grounding line retreat in West Antarctica.
Maria T. Kappelsberger, Martin Horwath, Eric Buchta, Matthias O. Willen, Ludwig Schröder, Sanne B. M. Veldhuijsen, Peter Kuipers Munneke, and Michiel R. van den Broeke
The Cryosphere, 18, 4355–4378, https://doi.org/10.5194/tc-18-4355-2024, https://doi.org/10.5194/tc-18-4355-2024, 2024
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The interannual variations in the height of the Antarctic Ice Sheet (AIS) are mainly due to natural variations in snowfall. Precise knowledge of these variations is important for the detection of any long-term climatic trends in AIS surface elevation. We present a new product that spatially resolves these height variations over the period 1992–2017. The product combines the strengths of atmospheric modeling results and satellite altimetry measurements.
Erwin Lambert and Clara Burgard
EGUsphere, https://doi.org/10.5194/egusphere-2024-2358, https://doi.org/10.5194/egusphere-2024-2358, 2024
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The effect of ocean warming on Antarctic ice sheet melting is a major source of uncertainty in estimates of future sea-level rise. We compare five melt models to show that ocean warming strongly increases melting. Despite their calibration on present-day melting, the models disagree on the amount of melt increase. In some important regions, the difference reaches a factor 100. We conclude that using various melt models is important to accurately estimate uncertainties in future sea-level rise.
Torsten Albrecht, Meike Bagge, and Volker Klemann
The Cryosphere, 18, 4233–4255, https://doi.org/10.5194/tc-18-4233-2024, https://doi.org/10.5194/tc-18-4233-2024, 2024
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We performed coupled ice sheet–solid Earth simulations and discovered a positive (forebulge) feedback mechanism for advancing grounding lines, supporting a larger West Antarctic Ice Sheet during the Last Glacial Maximum. During deglaciation we found that the stabilizing glacial isostatic adjustment feedback dominates grounding-line retreat in the Ross Sea, with a weak Earth structure. This may have consequences for present and future ice sheet stability and potential rates of sea-level rise.
W. Roger Buck
The Cryosphere, 18, 4165–4176, https://doi.org/10.5194/tc-18-4165-2024, https://doi.org/10.5194/tc-18-4165-2024, 2024
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Standard theory predicts that the edge of an ice shelf should bend downward. Satellite observations show that the edges of many ice shelves bend upward. A new theory for ice shelf bending is developed that, for the first time, includes the kind of vertical variations in ice flow properties expected for ice shelves. Upward bending of shelf edges is predicted as long as the ice surface is very cold and the ice flow properties depend strongly on temperature.
Johannes Feldmann, Anders Levermann, and Ricarda Winkelmann
The Cryosphere, 18, 4011–4028, https://doi.org/10.5194/tc-18-4011-2024, https://doi.org/10.5194/tc-18-4011-2024, 2024
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Here we show in simplified simulations that the (ir)reversibility of the retreat of instability-prone, Antarctica-type glaciers can strongly depend on the depth of the bed depression they rest on. If it is sufficiently deep, then the destabilized glacier does not recover from its collapsed state. Our results suggest that glaciers resting on a wide and deep bed depression, such as Antarctica's Thwaites Glacier, are particularly susceptible to irreversible retreat.
Marissa E. Dattler, Brooke Medley, and C. Max Stevens
The Cryosphere, 18, 3613–3631, https://doi.org/10.5194/tc-18-3613-2024, https://doi.org/10.5194/tc-18-3613-2024, 2024
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We developed an algorithm based on combining models and satellite observations to identify the presence of surface melt on the Antarctic Ice Sheet. We find that this method works similarly to previous methods by assessing 13 sites and the Larsen C ice shelf. Unlike previous methods, this algorithm is based on physical parameters, and updates to this method could allow the meltwater present on the Antarctic Ice Sheet to be quantified instead of simply detected.
Christoph Welling and The RNO-G Collaboration
The Cryosphere, 18, 3433–3437, https://doi.org/10.5194/tc-18-3433-2024, https://doi.org/10.5194/tc-18-3433-2024, 2024
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We report on the measurement of the index of refraction in glacial ice at radio frequencies. We show that radio echoes from within the ice can be associated with specific features of the ice conductivity and use this to determine the wave velocity. This measurement is especially relevant for the Radio Neutrino Observatory Greenland (RNO-G), a neutrino detection experiment currently under construction at Summit Station, Greenland.
Benjamin J. Davison, Anna E. Hogg, Carlos Moffat, Michael P. Meredith, and Benjamin J. Wallis
The Cryosphere, 18, 3237–3251, https://doi.org/10.5194/tc-18-3237-2024, https://doi.org/10.5194/tc-18-3237-2024, 2024
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Using a new dataset of ice motion, we observed glacier acceleration on the west coast of the Antarctic Peninsula. The speed-up began around January 2021, but some glaciers sped up earlier or later. Using a combination of ship-based ocean temperature observations and climate models, we show that the speed-up coincided with a period of unusually warm air and ocean temperatures in the region.
Floriane Provost, Dimitri Zigone, Emmanuel Le Meur, Jean-Philippe Malet, and Clément Hibert
The Cryosphere, 18, 3067–3079, https://doi.org/10.5194/tc-18-3067-2024, https://doi.org/10.5194/tc-18-3067-2024, 2024
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The recent calving of Astrolabe Glacier in November 2021 presents an opportunity to better understand the processes leading to ice fracturing. Optical-satellite imagery is used to retrieve the calving cycle of the glacier ice tongue and to measure the ice velocity and strain rates in order to document fracture evolution. We observed that the presence of sea ice for consecutive years has favoured the glacier extension but failed to inhibit the growth of fractures that accelerated in June 2021.
Hameed Moqadam and Olaf Eisen
EGUsphere, https://doi.org/10.5194/egusphere-2024-1674, https://doi.org/10.5194/egusphere-2024-1674, 2024
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This is an overview on methodologies that have been applied to map the internal reflection horizons, or ice-layer boundaries, of ice sheets on earth and other planets. We briefly explain radar applications in glaciology and the methods which have been used and published. There are summaries of the published work of the last two decades. Finally, we conclude by introducing the gaps and opportunities for further advancement in this field, and present possible future directions.
Cristina Gerli, Sebastian Rosier, G. Hilmar Gudmundsson, and Sainan Sun
The Cryosphere, 18, 2677–2689, https://doi.org/10.5194/tc-18-2677-2024, https://doi.org/10.5194/tc-18-2677-2024, 2024
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Recent efforts have focused on using AI and satellite imagery to track crevasses for assessing ice shelf damage and informing ice flow models. Our study reveals a weak connection between these observed products and damage maps inferred from ice flow models. While there is some improvement in crevasse-dense regions, this association remains limited. Directly mapping ice damage from satellite observations may not significantly improve the representation of these processes within ice flow models.
Charlotte M. Carter, Michael J. Bentley, Stewart S. R. Jamieson, Guy J. G. Paxman, Tom A. Jordan, Julien A. Bodart, Neil Ross, and Felipe Napoleoni
The Cryosphere, 18, 2277–2296, https://doi.org/10.5194/tc-18-2277-2024, https://doi.org/10.5194/tc-18-2277-2024, 2024
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We use radio-echo sounding data to investigate the presence of flat surfaces beneath the Evans–Rutford region in West Antarctica. These surfaces may be what remains of laterally continuous surfaces, formed before the inception of the West Antarctic Ice Sheet, and we assess two hypotheses for their formation. Tectonic structures in the region may have also had a control on the growth of the ice sheet by focusing ice flow into troughs adjoining these surfaces.
Rebecca B. Latto, Ross J. Turner, Anya M. Reading, and J. Paul Winberry
The Cryosphere, 18, 2061–2079, https://doi.org/10.5194/tc-18-2061-2024, https://doi.org/10.5194/tc-18-2061-2024, 2024
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The study of icequakes allows for investigation of many glacier processes that are unseen by typical reconnaissance methods. However, detection of such seismic signals is challenging due to low signal-to-noise levels and diverse source mechanisms. Here we present a novel algorithm that is optimized to detect signals from a glacier environment. We apply the algorithm to seismic data recorded in the 2010–2011 austral summer from the Whillans Ice Stream and evaluate the resulting event catalogue.
Rebecca B. Latto, Ross J. Turner, Anya M. Reading, Sue Cook, Bernd Kulessa, and J. Paul Winberry
The Cryosphere, 18, 2081–2101, https://doi.org/10.5194/tc-18-2081-2024, https://doi.org/10.5194/tc-18-2081-2024, 2024
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Seismic catalogues are potentially rich sources of information on glacier processes. In a companion study, we constructed an event catalogue for seismic data from the Whillans Ice Stream. Here, we provide a semi-automated workflow for consistent catalogue analysis using an unsupervised cluster analysis. We discuss the defining characteristics of identified signal types found in this catalogue and possible mechanisms for the underlying glacier processes and noise sources.
Jan De Rydt and Kaitlin Naughten
The Cryosphere, 18, 1863–1888, https://doi.org/10.5194/tc-18-1863-2024, https://doi.org/10.5194/tc-18-1863-2024, 2024
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The West Antarctic Ice Sheet is losing ice at an accelerating pace. This is largely due to the presence of warm ocean water around the periphery of the Antarctic continent, which melts the ice. It is generally assumed that the strength of this process is controlled by the temperature of the ocean. However, in this study we show that an equally important role is played by the changing geometry of the ice sheet, which affects the strength of the ocean currents and thereby the melt rates.
Hanwen Zhang, Richard F. Katz, and Laura A. Stevens
EGUsphere, https://doi.org/10.48550/arXiv.2311.01249, https://doi.org/10.48550/arXiv.2311.01249, 2024
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In Antarctica, supraglacial lakes are formed by melting near the grounding lines, where grounded ice sheets transition to floating ice shelves. We model the tidal flexure near the grounding lines and analyse its contribution to lake drainage through hydrofracturing. We show that tidal flexure and lake water pressure together control lake drainage in the Amery Ice Shelf, which indicates the importance of tidal stress to processes associated with hydrofracturing near the grounding lines.
Edmund J. Lea, Stewart S. R. Jamieson, and Michael J. Bentley
The Cryosphere, 18, 1733–1751, https://doi.org/10.5194/tc-18-1733-2024, https://doi.org/10.5194/tc-18-1733-2024, 2024
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We use the ice surface expression of the Gamburtsev Subglacial Mountains in East Antarctica to map the horizontal pattern of valleys and ridges in finer detail than possible from previous methods. In upland areas, valleys are spaced much less than 5 km apart, with consequences for the distribution of melting at the bed and hence the likelihood of ancient ice being preserved. Automated mapping techniques were tested alongside manual approaches, with a hybrid approach recommended for future work.
In-Woo Park, Emilia Kyung Jin, Mathieu Morlighem, and Kang-Kun Lee
The Cryosphere, 18, 1139–1155, https://doi.org/10.5194/tc-18-1139-2024, https://doi.org/10.5194/tc-18-1139-2024, 2024
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This study conducted 3D thermodynamic ice sheet model experiments, and modeled temperatures were compared with 15 observed borehole temperature profiles. We found that using incompressibility of ice without sliding agrees well with observed temperature profiles in slow-flow regions, while incorporating sliding in fast-flow regions captures observed temperature profiles. Also, the choice of vertical velocity scheme has a greater impact on the shape of the modeled temperature profile.
Sindhu Ramanath Tarekere, Lukas Krieger, Dana Floricioiu, and Konrad Heidler
EGUsphere, https://doi.org/10.5194/egusphere-2024-223, https://doi.org/10.5194/egusphere-2024-223, 2024
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Grounding lines are geophysical features that divide ice masses on the bedrock and floating ice shelves. Their accurate location is required for calculating the mass balance of ice sheets and glaciers in Antarctica and Greenland. Human experts still manually detect them in satellite-based interferometric radar images, which is inefficient given the growing volume of data. We have developed an artificial intelligence-based automatic detection algorithm to generate Antarctic-wide grounding lines.
Matthew A. Danielson and Philip J. Bart
The Cryosphere, 18, 1125–1138, https://doi.org/10.5194/tc-18-1125-2024, https://doi.org/10.5194/tc-18-1125-2024, 2024
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The post-Last Glacial Maximum (LGM) retreat of the West Antarctic Ice Sheet in the Ross Sea was more significant than for any other Antarctic sector. Here we combined the available dates of retreat with new mapping of sediment deposited by the ice sheet during overall retreat. Our work shows that the post-LGM retreat through the Ross Sea was not uniform. This uneven retreat can cause instability in the present-day Antarctic ice sheet configuration and lead to future runaway retreat.
Trystan Surawy-Stepney, Anna E. Hogg, Stephen L. Cornford, Benjamin J. Wallis, Benjamin J. Davison, Heather L. Selley, Ross A. W. Slater, Elise K. Lie, Livia Jakob, Andrew Ridout, Noel Gourmelen, Bryony I. D. Freer, Sally F. Wilson, and Andrew Shepherd
The Cryosphere, 18, 977–993, https://doi.org/10.5194/tc-18-977-2024, https://doi.org/10.5194/tc-18-977-2024, 2024
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Here, we use satellite observations and an ice flow model to quantify the impact of sea ice buttressing on ice streams on the Antarctic Peninsula. The evacuation of 11-year-old landfast sea ice in the Larsen B embayment on the East Antarctic Peninsula in January 2022 was closely followed by major changes in the calving behaviour and acceleration (30 %) of the ocean-terminating glaciers. Our results show that sea ice buttressing had a negligible direct role in the observed dynamic changes.
Andrew N. Hennig, David A. Mucciarone, Stanley S. Jacobs, Richard A. Mortlock, and Robert B. Dunbar
The Cryosphere, 18, 791–818, https://doi.org/10.5194/tc-18-791-2024, https://doi.org/10.5194/tc-18-791-2024, 2024
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A total of 937 seawater paired oxygen isotope (δ18O)–salinity samples collected during seven cruises on the SE Amundsen Sea between 1994 and 2020 reveal a deep freshwater source with δ18O − 29.4±1.0‰, consistent with the signature of local ice shelf melt. Local mean meteoric water content – comprised primarily of glacial meltwater – increased between 1994 and 2020 but exhibited greater interannual variability than increasing trend.
Qinggang Gao, Louise C. Sime, Alison J. McLaren, Thomas J. Bracegirdle, Emilie Capron, Rachael H. Rhodes, Hans Christian Steen-Larsen, Xiaoxu Shi, and Martin Werner
The Cryosphere, 18, 683–703, https://doi.org/10.5194/tc-18-683-2024, https://doi.org/10.5194/tc-18-683-2024, 2024
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Antarctic precipitation is a crucial component of the climate system. Its spatio-temporal variability impacts sea level changes and the interpretation of water isotope measurements in ice cores. To better understand its climatic drivers, we developed water tracers in an atmospheric model to identify moisture source conditions from which precipitation originates. We find that mid-latitude surface winds exert an important control on moisture availability for Antarctic precipitation.
Violaine Coulon, Ann Kristin Klose, Christoph Kittel, Tamsin Edwards, Fiona Turner, Ricarda Winkelmann, and Frank Pattyn
The Cryosphere, 18, 653–681, https://doi.org/10.5194/tc-18-653-2024, https://doi.org/10.5194/tc-18-653-2024, 2024
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We present new projections of the evolution of the Antarctic ice sheet until the end of the millennium, calibrated with observations. We show that the ocean will be the main trigger of future ice loss. As temperatures continue to rise, the atmosphere's role may shift from mitigating to amplifying Antarctic mass loss already by the end of the century. For high-emission scenarios, this may lead to substantial sea-level rise. Adopting sustainable practices would however reduce the rate of ice loss.
Hélène Seroussi, Vincent Verjans, Sophie Nowicki, Antony J. Payne, Heiko Goelzer, William H. Lipscomb, Ayako Abe-Ouchi, Cécile Agosta, Torsten Albrecht, Xylar Asay-Davis, Alice Barthel, Reinhard Calov, Richard Cullather, Christophe Dumas, Benjamin K. Galton-Fenzi, Rupert Gladstone, Nicholas R. Golledge, Jonathan M. Gregory, Ralf Greve, Tore Hattermann, Matthew J. Hoffman, Angelika Humbert, Philippe Huybrechts, Nicolas C. Jourdain, Thomas Kleiner, Eric Larour, Gunter R. Leguy, Daniel P. Lowry, Chistopher M. Little, Mathieu Morlighem, Frank Pattyn, Tyler Pelle, Stephen F. Price, Aurélien Quiquet, Ronja Reese, Nicole-Jeanne Schlegel, Andrew Shepherd, Erika Simon, Robin S. Smith, Fiammetta Straneo, Sainan Sun, Luke D. Trusel, Jonas Van Breedam, Peter Van Katwyk, Roderik S. W. van de Wal, Ricarda Winkelmann, Chen Zhao, Tong Zhang, and Thomas Zwinger
The Cryosphere, 17, 5197–5217, https://doi.org/10.5194/tc-17-5197-2023, https://doi.org/10.5194/tc-17-5197-2023, 2023
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Mass loss from Antarctica is a key contributor to sea level rise over the 21st century, and the associated uncertainty dominates sea level projections. We highlight here the Antarctic glaciers showing the largest changes and quantify the main sources of uncertainty in their future evolution using an ensemble of ice flow models. We show that on top of Pine Island and Thwaites glaciers, Totten and Moscow University glaciers show rapid changes and a strong sensitivity to warmer ocean conditions.
Lena Nicola, Ronja Reese, Moritz Kreuzer, Torsten Albrecht, and Ricarda Winkelmann
EGUsphere, https://doi.org/10.5194/egusphere-2023-2583, https://doi.org/10.5194/egusphere-2023-2583, 2023
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We identify potential oceanic gateways to Antarctic grounding lines based on high-resolution bathymetry data and examine the effect of critical access depths on basal melt rates. These gateways manifest the deepest topographic features that connect the deeper open ocean and the ice-shelf cavity. We detect 'prominent' oceanic gateways in some Antarctic regions and estimate an upper limit of melt rate changes in case all warm water masses gain access to the cavities.
Joel A. Wilner, Mathieu Morlighem, and Gong Cheng
The Cryosphere, 17, 4889–4901, https://doi.org/10.5194/tc-17-4889-2023, https://doi.org/10.5194/tc-17-4889-2023, 2023
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We use numerical modeling to study iceberg calving off of ice shelves in Antarctica. We examine four widely used mathematical descriptions of calving (
calving laws), under the assumption that Antarctic ice shelf front positions should be in steady state under the current climate forcing. We quantify how well each of these calving laws replicates the observed front positions. Our results suggest that the eigencalving and von Mises laws are most suitable for Antarctic ice shelves.
Rebecca J. Sanderson, Kate Winter, S. Louise Callard, Felipe Napoleoni, Neil Ross, Tom A. Jordan, and Robert G. Bingham
The Cryosphere, 17, 4853–4871, https://doi.org/10.5194/tc-17-4853-2023, https://doi.org/10.5194/tc-17-4853-2023, 2023
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Ice-penetrating radar allows us to explore the internal structure of glaciers and ice sheets to constrain past and present ice-flow conditions. In this paper, we examine englacial layers within the Lambert Glacier in East Antarctica using a quantitative layer tracing tool. Analysis reveals that the ice flow here has been relatively stable, but evidence for former fast flow along a tributary suggests that changes have occurred in the past and could change again in the future.
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Short summary
Using thousands of grounding line landforms in the Ross Sea, Antarctica, we observe two distinct landform types associated with contrasting styles of grounding line retreat. We characterise landform morphology, examine factors that control landform morphology and distribution, and explore drivers of grounding line (in)stability. This study highlights the importance of understanding thresholds which may destabilise a system and of controls on grounding line retreat over a range of timescales.
Using thousands of grounding line landforms in the Ross Sea, Antarctica, we observe two distinct...
