Articles | Volume 12, issue 7
https://doi.org/10.5194/tc-12-2401-2018
© 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-12-2401-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
24 Jul 2018
Research article |
| 24 Jul 2018
| 24 Jul 2018
Modelled fracture and calving on the Totten Ice Shelf
Antarctic Climate & Ecosystems Cooperative Research Centre, University of Tasmania, Private Bag 80, Hobart, Tasmania 7001, Australia
Jan Åström
CSC – IT Center for Science Ltd., 02101 Espoo, Finland
Thomas Zwinger
CSC – IT Center for Science Ltd., 02101 Espoo, Finland
Benjamin Keith Galton-Fenzi
Australian Antarctic Division, Kingston, Tasmania 7050, Australia
Antarctic Climate & Ecosystems Cooperative Research Centre, University of Tasmania, Private Bag 80, Hobart, Tasmania 7001, Australia
Jamin Stevens Greenbaum
Institute for Geophysics, University of Texas at Austin, Austin, TX 78758, USA
Richard Coleman
Institute for Marine and Antarctic Studies, University of Tasmania, Private Bag 129, Hobart, Tasmania 7001, Australia
Antarctic Climate & Ecosystems Cooperative Research Centre, University of Tasmania, Private Bag 80, Hobart, Tasmania 7001, Australia
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Lisa Craw, Adam Treverrow, Sheng Fan, Mark Peternell, Sue Cook, Felicity McCormack, and Jason Roberts
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Thomas Zwinger, Grace A. Nield, Juha Ruokolainen, and Matt A. King
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Joe Todd, Poul Christoffersen, Thomas Zwinger, Peter Råback, and Douglas I. Benn
The Cryosphere, 13, 1681–1694, https://doi.org/10.5194/tc-13-1681-2019, https://doi.org/10.5194/tc-13-1681-2019, 2019
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The Greenland Ice Sheet loses 30 %–60 % of its ice due to iceberg calving. Calving processes and their links to climate are not well understood or incorporated into numerical models of glaciers. Here we use a new 3-D calving model to investigate calving at Store Glacier, West Greenland, and test its sensitivity to increased submarine melting and reduced support from ice mélange (sea ice and icebergs). We find Store remains fairly stable despite these changes, but less so in the southern side.
Sue Cook, Benjamin K. Galton-Fenzi, Stefan R. M. Ligtenberg, and Richard Coleman
The Cryosphere, 12, 3853–3859, https://doi.org/10.5194/tc-12-3853-2018, https://doi.org/10.5194/tc-12-3853-2018, 2018
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Eef C. H. van Dongen, Nina Kirchner, Martin B. van Gijzen, Roderik S. W. van de Wal, Thomas Zwinger, Gong Cheng, Per Lötstedt, and Lina von Sydow
Geosci. Model Dev., 11, 4563–4576, https://doi.org/10.5194/gmd-11-4563-2018, https://doi.org/10.5194/gmd-11-4563-2018, 2018
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Ice flow forced by gravity is governed by the full Stokes (FS) equations, which are computationally expensive to solve. Therefore, approximations to the FS equations are used, especially when modeling an ice sheet on long time spans. Here, we report a combination of an approximation with the FS equations that allows simulating the dynamics of ice sheets over long time spans without introducing artifacts caused by application of approximations in parts of the domain where they are not valid.
Chad A. Greene, Duncan A. Young, David E. Gwyther, Benjamin K. Galton-Fenzi, and Donald D. Blankenship
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We show that Totten Ice Shelf accelerates each spring in response to the breakup of seasonal landfast sea ice at the ice shelf calving front. The previously unreported seasonal flow variability may have aliased measurements in at least one previous study of Totten's response to ocean forcing on interannual timescales. The role of sea ice in buttressing the flow of the ice shelf implies that long-term changes in sea ice cover could have impacts on the mass balance of the East Antarctic Ice Sheet.
Chen Zhao, Rupert M. Gladstone, Roland C. Warner, Matt A. King, Thomas Zwinger, and Mathieu Morlighem
The Cryosphere, 12, 2637–2652, https://doi.org/10.5194/tc-12-2637-2018, https://doi.org/10.5194/tc-12-2637-2018, 2018
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A combination of computer modelling and observational data were used to infer the resistance to ice flow at the bed of the Fleming Glacier on the Antarctic Peninsula. The model was also used to simulate the distribution of temperature within the ice, which governs the rate at which the ice can deform. This is especially important for glaciers like the Fleming Glacier, which has both regions of rapid deformation and regions of rapid sliding at the bed.
Chen Zhao, Rupert M. Gladstone, Roland C. Warner, Matt A. King, Thomas Zwinger, and Mathieu Morlighem
The Cryosphere, 12, 2653–2666, https://doi.org/10.5194/tc-12-2653-2018, https://doi.org/10.5194/tc-12-2653-2018, 2018
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A combination of computer modelling and observational data were used to infer the resistance to ice flow at the bed of the Fleming Glacier on the Antarctic Peninsula in both 2008 and 2015. The comparison suggests the grounding line retreated by ~ 9 km from 2008 to 2015. The retreat may be enhanced by a positive feedback between friction, melting and sliding at the glacier bed.
Lenneke M. Jong, Rupert M. Gladstone, Benjamin K. Galton-Fenzi, and Matt A. King
The Cryosphere, 12, 2425–2436, https://doi.org/10.5194/tc-12-2425-2018, https://doi.org/10.5194/tc-12-2425-2018, 2018
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We used an ice sheet model to simulate temporary regrounding of a marine ice sheet retreating across a retrograde bedrock slope. We show that a sliding relation incorporating water-filled cavities and the ice overburden pressure at the base allows the temporary regrounding to occur. This suggests that choice of basal sliding relation can be important when modelling grounding line behaviour of regions where potential ice rises and pinning points are present and regrounding could occur.
Yongmei Gong, Thomas Zwinger, Jan Åström, Bas Altena, Thomas Schellenberger, Rupert Gladstone, and John C. Moore
The Cryosphere, 12, 1563–1577, https://doi.org/10.5194/tc-12-1563-2018, https://doi.org/10.5194/tc-12-1563-2018, 2018
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In this study we apply a discrete element model capable of simulating ice fracturing. A microscopic-scale discrete process is applied in addition to a continuum ice dynamics model to investigate the mechanisms facilitated by basal meltwater production, surface meltwater and ice crack opening, for the surge in Basin 3, Austfonna ice cap. The discrete element model is used to locate the ice cracks that can penetrate though the full thickness of the glacier and deliver surface water to the bed.
Kaitlin A. Naughten, Katrin J. Meissner, Benjamin K. Galton-Fenzi, Matthew H. England, Ralph Timmermann, Hartmut H. Hellmer, Tore Hattermann, and Jens B. Debernard
Geosci. Model Dev., 11, 1257–1292, https://doi.org/10.5194/gmd-11-1257-2018, https://doi.org/10.5194/gmd-11-1257-2018, 2018
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MetROMS and FESOM are two ocean/sea-ice models which resolve Antarctic ice-shelf cavities and consider thermodynamics at the ice-shelf base. We simulate the period 1992–2016 with both models, and with two options for resolution in FESOM, and compare output from the three simulations. Ice-shelf melt rates, sub-ice-shelf circulation, continental shelf water masses, and sea-ice processes are compared and evaluated against available observations.
Dorothée Vallot, Jan Åström, Thomas Zwinger, Rickard Pettersson, Alistair Everett, Douglas I. Benn, Adrian Luckman, Ward J. J. van Pelt, Faezeh Nick, and Jack Kohler
The Cryosphere, 12, 609–625, https://doi.org/10.5194/tc-12-609-2018, https://doi.org/10.5194/tc-12-609-2018, 2018
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This paper presents a new perspective on the role of ice dynamics and ocean interaction in glacier calving processes applied to Kronebreen, a tidewater glacier in Svalbard. A global modelling approach includes ice flow modelling, undercutting estimation by a combination of glacier energy balance and plume modelling as well as calving by a discrete particle model. We show that modelling undercutting is necessary and calving is influenced by basal friction velocity and geometry.
Hakime Seddik, Ralf Greve, Thomas Zwinger, and Shin Sugiyama
The Cryosphere, 11, 2213–2229, https://doi.org/10.5194/tc-11-2213-2017, https://doi.org/10.5194/tc-11-2213-2017, 2017
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The Shirase Glacier in Antarctica is studied by means of a computer model. This model implements two physical approaches to represent the glacier flow dynamics. This study finds that it is important to use the more precise and sophisticated method in order to better understand and predict the evolution of fast flowing glaciers. This may be important to more accurately predict the sea level change due to global warming.
Felicity S. Graham, Jason L. Roberts, Ben K. Galton-Fenzi, Duncan Young, Donald Blankenship, and Martin J. Siegert
Earth Syst. Sci. Data, 9, 267–279, https://doi.org/10.5194/essd-9-267-2017, https://doi.org/10.5194/essd-9-267-2017, 2017
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Antarctic bed topography datasets are interpolated onto low-resolution grids because our observed topography data are sparsely sampled. This has implications for ice-sheet model simulations, especially in regions prone to instability, such as grounding lines, where detailed knowledge of the topography is required. Here, we constructed a high-resolution synthetic bed elevation dataset using observed covariance properties to assess the dependence of simulated ice-sheet dynamics on grid resolution.
Rupert Michael Gladstone, Roland Charles Warner, Benjamin Keith Galton-Fenzi, Olivier Gagliardini, Thomas Zwinger, and Ralf Greve
The Cryosphere, 11, 319–329, https://doi.org/10.5194/tc-11-319-2017, https://doi.org/10.5194/tc-11-319-2017, 2017
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Computer models are used to simulate the behaviour of glaciers and ice sheets. It has been found that such models are required to be run at very high resolution (which means high computational expense) in order to accurately represent the evolution of marine ice sheets (ice sheets resting on bedrock below sea level), in certain situations which depend on sub-glacial physical processes.
Christopher J. Fogwill, Erik van Sebille, Eva A. Cougnon, Chris S. M. Turney, Steve R. Rintoul, Benjamin K. Galton-Fenzi, Graeme F. Clark, E. M. Marzinelli, Eleanor B. Rainsley, and Lionel Carter
The Cryosphere, 10, 2603–2609, https://doi.org/10.5194/tc-10-2603-2016, https://doi.org/10.5194/tc-10-2603-2016, 2016
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Here we report new data from in situ oceanographic surveys and high-resolution ocean modelling experiments in the Commonwealth Bay region of East Antarctica, where in 2010 there was a major reconfiguration of the regional icescape due to the collision of the 97 km long iceberg B09B with the Mertz Glacier tongue. Here we compare post-calving observations with high-resolution ocean modelling which suggest that this reconfiguration has led to the development of a new polynya off Commonwealth Bay.
T. Zwinger, T. Malm, M. Schäfer, R. Stenberg, and J. C. Moore
The Cryosphere, 9, 1415–1426, https://doi.org/10.5194/tc-9-1415-2015, https://doi.org/10.5194/tc-9-1415-2015, 2015
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By deploying a large-scale high-resolution turbulent CFD simulation using the present-day topography of the Scharffenbergbotnen (SBB) valley, we show how the surrounding topography redirects incoming easterly katabatic storm fronts to impact the blue ice areas (BIA) inside the valley, where the snow cover frequently is removed. A further simulation of a reconstructed topography at the Late Glacial Maximum further reveals that the BIA at SBB must have formed after this period.
M. Schäfer, F. Gillet-Chaulet, R. Gladstone, R. Pettersson, V. A. Pohjola, T. Strozzi, and T. Zwinger
The Cryosphere, 8, 1951–1973, https://doi.org/10.5194/tc-8-1951-2014, https://doi.org/10.5194/tc-8-1951-2014, 2014
R. Gladstone, M. Schäfer, T. Zwinger, Y. Gong, T. Strozzi, R. Mottram, F. Boberg, and J. C. Moore
The Cryosphere, 8, 1393–1405, https://doi.org/10.5194/tc-8-1393-2014, https://doi.org/10.5194/tc-8-1393-2014, 2014
B. Sun, J. C. Moore, T. Zwinger, L. Zhao, D. Steinhage, X. Tang, D. Zhang, X. Cui, and C. Martín
The Cryosphere, 8, 1121–1128, https://doi.org/10.5194/tc-8-1121-2014, https://doi.org/10.5194/tc-8-1121-2014, 2014
S. Cook, I. C. Rutt, T. Murray, A. Luckman, T. Zwinger, N. Selmes, A. Goldsack, and T. D. James
The Cryosphere, 8, 827–841, https://doi.org/10.5194/tc-8-827-2014, https://doi.org/10.5194/tc-8-827-2014, 2014
T. Zwinger, M. Schäfer, C. Martín, and J. C. Moore
The Cryosphere, 8, 607–621, https://doi.org/10.5194/tc-8-607-2014, https://doi.org/10.5194/tc-8-607-2014, 2014
T. Sato, T. Shiraiwa, R. Greve, H. Seddik, E. Edelmann, and T. Zwinger
Clim. Past, 10, 393–404, https://doi.org/10.5194/cp-10-393-2014, https://doi.org/10.5194/cp-10-393-2014, 2014
B. de Fleurian, O. Gagliardini, T. Zwinger, G. Durand, E. Le Meur, D. Mair, and P. Råback
The Cryosphere, 8, 137–153, https://doi.org/10.5194/tc-8-137-2014, https://doi.org/10.5194/tc-8-137-2014, 2014
J. A. Åström, T. I. Riikilä, T. Tallinen, T. Zwinger, D. Benn, J. C. Moore, and J. Timonen
The Cryosphere, 7, 1591–1602, https://doi.org/10.5194/tc-7-1591-2013, https://doi.org/10.5194/tc-7-1591-2013, 2013
O. Gagliardini, T. Zwinger, F. Gillet-Chaulet, G. Durand, L. Favier, B. de Fleurian, R. Greve, M. Malinen, C. Martín, P. Råback, J. Ruokolainen, M. Sacchettini, M. Schäfer, H. Seddik, and J. Thies
Geosci. Model Dev., 6, 1299–1318, https://doi.org/10.5194/gmd-6-1299-2013, https://doi.org/10.5194/gmd-6-1299-2013, 2013
A. S. Drouet, D. Docquier, G. Durand, R. Hindmarsh, F. Pattyn, O. Gagliardini, and T. Zwinger
The Cryosphere, 7, 395–406, https://doi.org/10.5194/tc-7-395-2013, https://doi.org/10.5194/tc-7-395-2013, 2013
L. Zhao, L. Tian, T. Zwinger, R. Ding, J. Zong, Q. Ye, and J. C. Moore
The Cryosphere Discuss., https://doi.org/10.5194/tcd-7-145-2013, https://doi.org/10.5194/tcd-7-145-2013, 2013
Revised manuscript not accepted
F. Gillet-Chaulet, O. Gagliardini, H. Seddik, M. Nodet, G. Durand, C. Ritz, T. Zwinger, R. Greve, and D. G. Vaughan
The Cryosphere, 6, 1561–1576, https://doi.org/10.5194/tc-6-1561-2012, https://doi.org/10.5194/tc-6-1561-2012, 2012
Related subject area
Discipline: Ice sheets | Subject: Ice Sheets
Probabilistic projections of the Amery Ice Shelf catchment, Antarctica, under conditions of high ice-shelf basal melt
Reconstructing dynamics of the Baltic Ice Stream Complex during deglaciation of the Last Scandinavian Ice Sheet
The influence of firn-layer material properties on surface crevasse propagation in glaciers and ice shelves
Assessing the potential for ice flow piracy between the Totten and Vanderford glaciers, East Antarctica
Stagnant ice and age modelling in the Dome C region, Antarctica
Polar firn properties in Greenland and Antarctica and related effects on microwave brightness temperatures
A model of the weathering crust and microbial activity on an ice-sheet surface
PISM-LakeCC: Implementing an adaptive proglacial lake boundary in an ice sheet model
Remapping of Greenland ice sheet surface mass balance anomalies for large ensemble sea-level change projections
Brief communication: On calculating the sea-level contribution in marine ice-sheet models
A simple stress-based cliff-calving law
Scaling of instability timescales of Antarctic outlet glaciers based on one-dimensional similitude analysis
A statistical fracture model for Antarctic ice shelves and glaciers
Sanket Jantre, Matthew J. Hoffman, Nathan M. Urban, Trevor Hillebrand, Mauro Perego, Stephen Price, and John D. Jakeman
The Cryosphere, 18, 5207–5238, https://doi.org/10.5194/tc-18-5207-2024, https://doi.org/10.5194/tc-18-5207-2024, 2024
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We investigate potential sea-level rise from Antarctica's Lambert Glacier, once considered stable but now at risk due to projected ocean warming by 2100. Using statistical methods and limited supercomputer simulations, we calibrated our ice-sheet model using three observables. We find that, under high greenhouse gas emissions, glacier retreat could raise sea levels by 46–133 mm by 2300. This study highlights the need for better observations to reduce uncertainty in ice-sheet model projections.
Izabela Szuman, Jakub Z. Kalita, Christiaan R. Diemont, Stephen J. Livingstone, Chris D. Clark, and Martin Margold
The Cryosphere, 18, 2407–2428, https://doi.org/10.5194/tc-18-2407-2024, https://doi.org/10.5194/tc-18-2407-2024, 2024
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A Baltic-wide glacial landform-based map is presented, filling in a geographical gap in the record that has been speculated about by palaeoglaciologists for over a century. Here we used newly available bathymetric data and provide landform evidence of corridors of fast ice flow that we interpret as ice streams. Where previous ice-sheet-scale investigations inferred a single ice source, our mapping identifies flow and ice margin geometries from both Swedish and Bothnian sources.
Theo Clayton, Ravindra Duddu, Tim Hageman, and Emilio Martinez-Paneda
EGUsphere, https://doi.org/10.5194/egusphere-2024-660, https://doi.org/10.5194/egusphere-2024-660, 2024
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We develop and validate new analytical solutions that quantitatively consider how the properties of ice vary along the depth of ice shelves and can be readily used in existing ice sheet models. Depth-varying firn properties are found to have a profound impact on ice sheet fracture and calving events. Our results show that grounded glaciers are less vulnerable than previously anticipated while floating ice shelves are significantly more vulnerable to fracture and calving.
Felicity S. McCormack, Jason L. Roberts, Bernd Kulessa, Alan Aitken, Christine F. Dow, Lawrence Bird, Benjamin K. Galton-Fenzi, Katharina Hochmuth, Richard S. Jones, Andrew N. Mackintosh, and Koi McArthur
The Cryosphere, 17, 4549–4569, https://doi.org/10.5194/tc-17-4549-2023, https://doi.org/10.5194/tc-17-4549-2023, 2023
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Changes in Antarctic surface elevation can cause changes in ice and basal water flow, impacting how much ice enters the ocean. We find that ice and basal water flow could divert from the Totten to the Vanderford Glacier, East Antarctica, under only small changes in the surface elevation, with implications for estimates of ice loss from this region. Further studies are needed to determine when this could occur and if similar diversions could occur elsewhere in Antarctica due to climate change.
Ailsa Chung, Frédéric Parrenin, Daniel Steinhage, Robert Mulvaney, Carlos Martín, Marie G. P. Cavitte, David A. Lilien, Veit Helm, Drew Taylor, Prasad Gogineni, Catherine Ritz, Massimo Frezzotti, Charles O'Neill, Heinrich Miller, Dorthe Dahl-Jensen, and Olaf Eisen
The Cryosphere, 17, 3461–3483, https://doi.org/10.5194/tc-17-3461-2023, https://doi.org/10.5194/tc-17-3461-2023, 2023
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We combined a numerical model with radar measurements in order to determine the age of ice in the Dome C region of Antarctica. Our results show that at the current ice core drilling sites on Little Dome C, the maximum age of the ice is almost 1.5 Ma. We also highlight a new potential drill site called North Patch with ice up to 2 Ma. Finally, we explore the nature of a stagnant ice layer at the base of the ice sheet which has been independently observed and modelled but is not well understood.
Haokui Xu, Brooke Medley, Leung Tsang, Joel T. Johnson, Kenneth C. Jezek, Macro Brogioni, and Lars Kaleschke
The Cryosphere, 17, 2793–2809, https://doi.org/10.5194/tc-17-2793-2023, https://doi.org/10.5194/tc-17-2793-2023, 2023
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The density profile of polar ice sheets is a major unknown in estimating the mass loss using lidar tomography methods. In this paper, we show that combing the active radar data and passive radiometer data can provide an estimation of density properties using the new model we implemented in this paper. The new model includes the short and long timescale variations in the firn and also the refrozen layers which are not included in the previous modeling work.
Tilly Woods and Ian J. Hewitt
The Cryosphere, 17, 1967–1987, https://doi.org/10.5194/tc-17-1967-2023, https://doi.org/10.5194/tc-17-1967-2023, 2023
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Solar radiation causes melting at and just below the surface of the Greenland ice sheet, forming a porous surface layer known as the weathering crust. The weathering crust is home to many microbes, and the growth of these microbes is linked to the melting of the weathering crust and vice versa. We use a mathematical model to investigate what controls the size and structure of the weathering crust, the number of microbes within it, and its sensitivity to climate change.
Sebastian Hinck, Evan J. Gowan, Xu Zhang, and Gerrit Lohmann
The Cryosphere, 16, 941–965, https://doi.org/10.5194/tc-16-941-2022, https://doi.org/10.5194/tc-16-941-2022, 2022
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Proglacial lakes were pervasive along the retreating continental ice margins after the Last Glacial Maximum. Similarly to the marine ice boundary, interactions at the ice-lake interface impact ice sheet dynamics and mass balance. Previous numerical ice sheet modeling studies did not include a dynamical lake boundary. We describe the implementation of an adaptive lake boundary condition in PISM and apply the model to the glacial retreat of the Laurentide Ice Sheet.
Heiko Goelzer, Brice P. Y. Noël, Tamsin L. Edwards, Xavier Fettweis, Jonathan M. Gregory, William H. Lipscomb, Roderik S. W. van de Wal, and Michiel R. van den Broeke
The Cryosphere, 14, 1747–1762, https://doi.org/10.5194/tc-14-1747-2020, https://doi.org/10.5194/tc-14-1747-2020, 2020
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Future sea-level change projections with process-based ice sheet models are typically driven with surface mass balance forcing derived from climate models. In this work we address the problems arising from a mismatch of the modelled ice sheet geometry with the one used by the climate model. The proposed remapping method reproduces the original forcing data closely when applied to the original geometry and produces a physically meaningful forcing when applied to different modelled geometries.
Heiko Goelzer, Violaine Coulon, Frank Pattyn, Bas de Boer, and Roderik van de Wal
The Cryosphere, 14, 833–840, https://doi.org/10.5194/tc-14-833-2020, https://doi.org/10.5194/tc-14-833-2020, 2020
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In our ice-sheet modelling experience and from exchange with colleagues in different groups, we found that it is not always clear how to calculate the sea-level contribution from a marine ice-sheet model. This goes hand in hand with a lack of documentation and transparency in the published literature on how the sea-level contribution is estimated in different models. With this brief communication, we hope to stimulate awareness and discussion in the community to improve on this situation.
Tanja Schlemm and Anders Levermann
The Cryosphere, 13, 2475–2488, https://doi.org/10.5194/tc-13-2475-2019, https://doi.org/10.5194/tc-13-2475-2019, 2019
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We provide a simple stress-based parameterization for cliff calving of ice sheets. According to the resulting increasing dependence of the calving rate on ice thickness, the parameterization might lead to a runaway ice loss in large parts of Greenland and Antarctica.
Anders Levermann and Johannes Feldmann
The Cryosphere, 13, 1621–1633, https://doi.org/10.5194/tc-13-1621-2019, https://doi.org/10.5194/tc-13-1621-2019, 2019
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Using scaling analysis we propose that the currently observed marine ice-sheet instability in the Amundsen Sea sector might be faster than all other potential instabilities in Antarctica.
Veronika Emetc, Paul Tregoning, Mathieu Morlighem, Chris Borstad, and Malcolm Sambridge
The Cryosphere, 12, 3187–3213, https://doi.org/10.5194/tc-12-3187-2018, https://doi.org/10.5194/tc-12-3187-2018, 2018
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The paper includes a model that can be used to predict zones of fracture formation in both floating and grounded ice in Antarctica. We used observations and a statistics-based model to predict fractures in most ice shelves in Antarctica as an alternative to the damage-based approach. We can predict the location of observed fractures with an average success rate of 84% for grounded ice and 61% for floating ice and mean overestimation error of 26% and 20%, respectively.
Cited articles
Aitken, A. R. A., Roberts, J. L., van Ommen, T. D., Young, D. A., Golledge, N.
R., Greenbaum, J. S., Blankenship, D. D., and Siegert, M. J.: Repeated
large-scale retreat and advance of Totten Glacier indicated by inland bed
erosion, Nature, 533, 385–389, https://doi.org/10.1038/nature17447, 2016.
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.
Åström, J. A.: Statistical models of brittle fragmentation, Adv. Phys.,
55, 247–278, https://doi.org/10.1080/00018730600731907, 2006.
Åström, J. A., Riikilä, T. I., Tallinen, T., Zwinger, T., Benn, D.,
Moore, J. C., and Timonen, J.: A particle based simulation model for glacier
dynamics, The Cryosphere, 7, 1591–1602, https://doi.org/10.5194/tc-7-1591-2013, 2013.
Åström, J. A., Vallot, D., Schäfer, M., Welty, E. Z., O'Neel, S.,
Bartholomaus, T. C., Liu, Y., Riikilä, T. I., Zwinger, T., Timonen, J., and
Moore, J. C.: Termini of calving glaciers as self-organized critical systems,
Nat. Geosci., 7, 874–878, https://doi.org/10.1038/ngeo2290, 2014.
Bassis, J. N. and Jacobs, S.: Diverse calving patterns linked to glacier geometry,
Nat. Geosci., 6, 833–836, https://doi.org/10.1038/ngeo1887, 2013.
Bassis, J. N. and Ma, Y.: Evolution of basal crevasses links ice shelf stability
to ocean forcing, Earth Planet. Sc. Lett., 409, 203–211, https://doi.org/10.1016/j.epsl.2014.11.003, 2015.
Benn, D. I., Warren, C. R., and Mottram, R. H.: Calving processes and the
dynamics of calving glaciers, Earth-Sci. Rev., 82, 143–179, https://doi.org/10.1016/j.earscirev.2007.02.002, 2007.
Benn, D. I., Åström, J. A., Zwinger, T., Todd, J., Nick, F. M., Cook,
S., Hulton, N. R. J. and Luckman, A.: Melt-under-cutting and buoyancy-driven
calving from tidewater glaciers: new insights from discrete element and
continuum model simulations, J. Glaciol., 63, 691–702, https://doi.org/10.1017/jog.2017.41, 2017.
Bindschadler, R., Choi, H., and ASAID Collaborators: High-resolution
image-derived grounding and hydrostatic lines for the Antarctic Ice Sheet,
https://doi.org/10.7265/N56T0JK2, 2011a.
Bindschadler, R., Vaughan, D. G., and Vornberger, P.: Variability of basal melt
beneath the Pine Island Glacier ice shelf, West Antarctica, J. Glaciol.,
57, 581–595, 2011b.
Blankenship, D. D., Kempf, S. D. and Young, D. A.: IceBridge HiCARS 2 L2
Geolocated Ice Thickness, Version 1, NASA National Snow and Ice, Boulder,
Colorado, USA, https://doi.org/10.5067/9EBR2T0VXUDG, 2012.
Blankenship, D. D., Kempf, S. D., Young, D. A., and Lindzey, L. E.: IceBridge
Photon Counting Lidar L1B Unclassified Geolocated Photon Elevations, Version 1,
NASA National Snow and Ice, Boulder, Colorado, USA, https://doi.org/10.5067/U3E4Q5WWVSP9, 2015.
Bonachela, J. A., Nadell, C. D., Xavier, J. B., and Levin, S. A.: Universality
in Bacterial Colonies, J. Stat. Phys., 144, 303–315, https://doi.org/10.1007/s10955-011-0179-x, 2011.
Deconto, R. M. and Pollard, D.: Contribution of Antarctica to past and future
sea-level rise, Nature, 531, 591–597, https://doi.org/10.1038/nature17145, 2016.
Depoorter, M. A., Bamber, J. L., Griggs, J. A., Lenaerts, J. T. M., Ligtenberg,
S. R. M., van den Broeke, M. R., and Moholdt, G.: Calving fluxes and basal melt
rates of Antarctic ice shelves, Nature, 502, 89–92, https://doi.org/10.1038/nature12567, 2013.
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.
Fürst, J. J., Durand, G., Gillet-Chaulet, F., Tavard, L., Rankl, M., Braun,
M., and Gagliardini, O.: The safety band of Antarctic ice shelves, Nat. Clim.
Change, 6, 479–482, https://doi.org/10.1038/NCLIMATE2912, 2016.
Gagliardini, O., Zwinger, T., Gillet-Chaulet, F., Durand, G., Favier, L.,
De Fleurian, B., Greve, R., Malinen, M., Martín, C., Räback, P.,
Ruokolainen, J., Sacchettini, M., Schäfer, M., Seddik, H., and Thies, J.:
Capabilities and performance of Elmer/Ice, a new-generation ice sheet model,
Geosci. Model Dev., 6, 1299–1318, https://doi.org/10.5194/gmd-6-1299-2013, 2013.
Greenbaum, J. S., Blankenship, D. D., Young, D. A., Richter, T. G., Roberts,
J. L., Aitken, A. R. A., Legrésy, B., Schroeder, D. M., Warner, R. C.,
van Ommen, T. D., and Siegert, M. J.: Ocean access to a cavity beneath Totten
Glacier in East Antarctica, Nat. Geosci., 8, 6–10, https://doi.org/10.1038/NGEO2388, 2015.
Gwyther, D. E., Galton-Fenzi, B. K., Hunter, J. R., and Roberts, J. L.:
Simulated melt rates for the Totten and Dalton ice shelves, Ocean Sci.,
10, 267–279, https://doi.org/10.5194/os-10-267-2014, 2014.
Jacobel, R. W., Christianson, K., Wood, A. C., Dallasanta, K. J., and Gobel, R.
M.: Morphology of basal crevasses at the grounding zone of Whillans Ice Stream,
West Antarctica, Ann. Glaciol., 55, 57–63, https://doi.org/10.3189/2014AoG67A004, 2014.
Jordan, J. R., Holland, P. R., Jenkins, A., Piggott, M. D., and Kimura, S.:
Modelling ice–ocean interaction in ice-shelf crevasses, J. Geophys. Res., 119,
2121–2128, https://doi.org/10.1002/jgrc.20224, 2014.
Kardar, M., Parisi, G., and Zhang, Y.-C.: Dynamic scaling of growing interfaces,
Phys. Rev. Lett., 56, 889–892, 1986.
Khazendar, A. and Jenkins, A.: A model of marine ice formation within Antarctic
ice shelf rifts, J. Geophys. Res., 108, 3235, https://doi.org/10.1029/2002JC001673, 2003.
Khazendar, A., Schodlok, M. P., Fenty, I., Ligtenberg, S. R. M., Rignot, E.,
and van den Broeke, M. R.: Observed thinning of Totten Glacier is linked to
coastal polynya variability, Nat. Commun., 4, 2857, https://doi.org/10.1038/ncomms3857, 2013.
Lam, F., Mi, X., and Higgins, A. J.: Front roughening of flames in discrete
media, Phys. Rev., 96, 13107, https://doi.org/10.1103/PhysRevE.96.013107, 2017.
Levermann, A., Winkelmann, R., Nowicki, S., Fastook, J. L., Frieler, K., Greve,
R., and Hellmer, H. H.: Projecting Antarctic ice discharge using response
functions from SeaRISE ice-sheet models, Earth Syst. Dynam., 5, 271–293,
https://doi.org/10.5194/esd-5-271-2014, 2014.
Li, X., Rignot, E., Mouginot, J., and Scheuchl, B.: Ice flow dynamics and mass
loss of Totten Glacier, East Antarctica from 1989 to 2015, Geophys. Res. Lett.,
43, 6366–6373, https://doi.org/10.1002/2016GL069173, 2016.
Liu, Y., Moore, J. C., Cheng, X., Gladstone, R. M., Bassis, J. N., Liu, H., Wen,
J., and Hui, F.: Ocean-driven thinning enhances iceberg calving and retreat of
Antarctic ice shelves, P. Natl. Acad. Sci. USA, 112, 3263–3268, https://doi.org/10.1073/pnas.1415137112, 2015.
Luckman, A., Jansen, D., Kulessa, B., King, E. C., Sammonds, P., and Benn, D.
I.: Basal crevasses in Larsen C Ice Shelf and implications for their global
abundance, The Cryosphere, 6, 113–123, https://doi.org/10.5194/tc-6-113-2012, 2012.
Millgate, T., Holland, P. R., Jenkins, A., and Johnson, H. L.: The effect of
basal channels on oceanic ice-shelf melting, J. Geophys. Res., 118, 6951–6964,
https://doi.org/10.1002/2013JC009402, 2013.
Mouginot, J., Scheuchl, B., and Rignot, E.: MEaSUREs Annual Antarctic Ice
Velocity Maps 2005–2017, Version 1, NASA National Snow and Ice Data Center
Distributed Active Archive Center, Boulder, Colorado, USA, https://doi.org/10.5067/9T4EPQXTJYW9, 2017a.
Mouginot, J., Rignot, E., Scheuchl, B., and Millan, R.: Comprehensive Annual
Ice Sheet Velocity Mapping Using Landsat-8, Sentinel-1, and RADARSAT-2 Data,
Remote Sensing, 9, 364, https://doi.org/10.3390/rs9040364, 2017b.
Paolo, F. S., Fricker, H. A., and Padman, L.: Volume loss from Antarctic ice
shelves is accelerating, Science, 348, 327–332, https://doi.org/10.1126/science.aaa0940, 2015.
Pollard, D., Deconto, R. M., and Alley, R. B.: Potential Antarctic Ice Sheet
retreat driven by hydrofracturing and ice cliff failure, Earth Planet. Sc. Lett.,
412, 112–121, https://doi.org/10.1016/j.epsl.2014.12.035, 2015.
Rignot, E., Jacobs, S., Mouginot, J., and Scheuchl, B.: Ice-shelf melting around
Antarctica, Science, 341, 266–270, 2013.
Riikilä, T. I., Tallinen, T., Åström, J., and Timonen, J.: A
discrete-element model for viscoelastic deformation and fracture of glacial ice,
Comput. Phys. Commun., 195, 14–22, https://doi.org/10.1016/j.cpc.2015.04.009, 2014.
Rintoul, S. R., Silvano, A., Pena-molino, B., Van Wijk, E. , Rosenberg, M.,
Greenbaum, J. S., and Blankenship, D. D.: Ocean heat drives rapid basal melt
of the Totten Ice Shelf, Sci. Adv., 2, e1601610, https://doi.org/10.1126/sciadv.160161, 2016.
Roberts, J., Galton-Fenzi, B. K., Paolo, F. S., Donnelly, C., Gwyther, D.
E., Padman, L., Young, D., Warner, R., Greenbaum, J., Fricker, H. A., Payne, A.
J., Cornford, S., Le Brocq, A. M., Van Ommen, T., Blankenship, D. D., and
Siegert, M. J.: Ocean forced variability of Totten Glacier mass loss, Special
Publications, Geological Society, London, 461, SP461-6, 2017.
Roberts, J. L., Warner, R. C., Young, D., Wright, A., Van Ommen, T. D.,
Blankenship, D. D., Siegert, M., Young, N. W., Tabacco, I. E., Forieri, A.,
Passerini, A., Zirizzotti, A., and Frezzotti, M.: Refined broad-scale sub-glacial
morphology of Aurora Subglacial Basin, East Antarctica derived by an
ice-dynamics-based interpolation scheme, The Cryosphere, 5, 551–560,
https://doi.org/10.5194/tc-5-551-2011, 2011.
Schoof, C.: Ice sheet grounding line dynamics: Steady states, stability, and
hysteresis, J. Geophys. Res., 112, F03S28, https://doi.org/10.1029/2006JF000664, 2007.
Tournadre, J., Bouhier, N., Girard-Ardhuin, F., and Remy, F.: Antarctic icebergs
distributions 1992–2014, J. Geophys. Res.-Oceans, 121, 327–349, https://doi.org/10.1002/2015JC010969, 2016.
Vallot, D., Åström, J., Zwinger, T., Pettersson, R., Everett, A., Benn,
D. I., Luckman, A., van Pelt, W. J. J., Nick, F., and Kohler, J.: Effects of
undercutting and sliding on calving: a global approach applied to Kronebreen,
Svalbard, The Cryosphere, 12, 609–625, https://doi.org/10.5194/tc-12-609-2018, 2018.
Weertman, J.: Stability of the junction of an ice sheet and an ice shelf, J.
Glaciol., 13, 3–11, 1974.
Wesche, C., Jansen, D., and Dierking, W.: Calving Fronts of Antarctica: Mapping
and Classification, Remote Sens., 5, 6305–6322, https://doi.org/10.3390/rs5126305, 2013.
Short summary
The growth of fractures on Antarctic ice shelves is important because it controls the amount of ice lost as icebergs. We use a model constructed of multiple interconnected blocks to predict the locations where fractures will form on the Totten Ice Shelf in East Antarctica. The results show that iceberg calving is controlled not only by fractures forming near the front of the ice shelf but also by fractures which formed many kilometres upstream.
The growth of fractures on Antarctic ice shelves is important because it controls the amount of...
