Articles | Volume 18, issue 2
https://doi.org/10.5194/tc-18-705-2024
© 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-18-705-2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Brief communication: Rapid acceleration of the Brunt Ice Shelf after calving of iceberg A-81
British Antarctic Survey, Cambridge, UK
Adrian J. Luckman
Department of Geography, Swansea University, Swansea, UK
Dominic A. Hodgson
British Antarctic Survey, Cambridge, UK
Related authors
Bryony I. D. Freer, Oliver J. Marsh, Anna E. Hogg, Helen Amanda Fricker, and Laurie Padman
The Cryosphere, 17, 4079–4101, https://doi.org/10.5194/tc-17-4079-2023, https://doi.org/10.5194/tc-17-4079-2023, 2023
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We develop a method using ICESat-2 data to measure how Antarctic grounding lines (GLs) migrate across the tide cycle. At an ice plain on the Ronne Ice Shelf we observe 15 km of tidal GL migration, the largest reported distance in Antarctica, dominating any signal of long-term migration. We identify four distinct migration modes, which provide both observational support for models of tidal ice flexure and GL migration and insights into ice shelf–ocean–subglacial interactions in grounding zones.
Ashley Morris, Bradley P. Lipovsky, Catherine C. Walker, and Oliver J. Marsh
The Cryosphere Discuss., https://doi.org/10.5194/tc-2023-63, https://doi.org/10.5194/tc-2023-63, 2023
Preprint under review for TC
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Floating ice shelves hold back Antarctic ice flow, but they are thinning and retreating. To help predict future mass loss we need a better understanding of the behavior of the rifts from which icebergs detach. We automate rift width measurement using surface elevation data from the ICESat-2 laser altimetry satellite, and validate using satellite images and GPS receivers placed around the "Halloween Crack" on Brunt Ice Shelf. We find rift opening stagnated following calving from an adjacent rift.
Christian T. Wild, Oliver J. Marsh, and Wolfgang Rack
The Cryosphere, 13, 3171–3191, https://doi.org/10.5194/tc-13-3171-2019, https://doi.org/10.5194/tc-13-3171-2019, 2019
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In Antarctica, ocean tides control the motion of ice sheets near the coastline as well as melt rates underneath the floating ice. By combining the spatial advantage of rare but highly accurate satellite images with the temporal advantage of tide-prediction models, vertical displacement of floating ice due to ocean tides can now be predicted accurately. This allows the detailed study of ice-flow dynamics in areas that matter the most to the stability of Antarctica's ice sheets.
Wolfgang Rack, Matt A. King, Oliver J. Marsh, Christian T. Wild, and Dana Floricioiu
The Cryosphere, 11, 2481–2490, https://doi.org/10.5194/tc-11-2481-2017, https://doi.org/10.5194/tc-11-2481-2017, 2017
Short summary
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Predicting changes of the Antarctic Ice Sheet involves fully understanding ice dynamics at the transition between grounded and floating ice. We map tidal bending of ice by satellite using InSAR, and we use precise GPS measurements with assumptions of tidal elastic bending to better interpret the satellite signal. It allows us to better define the grounding-line position and to refine the shape of tidal flexure profiles.
O. J. Marsh, W. Rack, D. Floricioiu, N. R. Golledge, and W. Lawson
The Cryosphere, 7, 1375–1384, https://doi.org/10.5194/tc-7-1375-2013, https://doi.org/10.5194/tc-7-1375-2013, 2013
Bryony I. D. Freer, Oliver J. Marsh, Anna E. Hogg, Helen Amanda Fricker, and Laurie Padman
The Cryosphere, 17, 4079–4101, https://doi.org/10.5194/tc-17-4079-2023, https://doi.org/10.5194/tc-17-4079-2023, 2023
Short summary
Short summary
We develop a method using ICESat-2 data to measure how Antarctic grounding lines (GLs) migrate across the tide cycle. At an ice plain on the Ronne Ice Shelf we observe 15 km of tidal GL migration, the largest reported distance in Antarctica, dominating any signal of long-term migration. We identify four distinct migration modes, which provide both observational support for models of tidal ice flexure and GL migration and insights into ice shelf–ocean–subglacial interactions in grounding zones.
Ashley Morris, Bradley P. Lipovsky, Catherine C. Walker, and Oliver J. Marsh
The Cryosphere Discuss., https://doi.org/10.5194/tc-2023-63, https://doi.org/10.5194/tc-2023-63, 2023
Preprint under review for TC
Short summary
Short summary
Floating ice shelves hold back Antarctic ice flow, but they are thinning and retreating. To help predict future mass loss we need a better understanding of the behavior of the rifts from which icebergs detach. We automate rift width measurement using surface elevation data from the ICESat-2 laser altimetry satellite, and validate using satellite images and GPS receivers placed around the "Halloween Crack" on Brunt Ice Shelf. We find rift opening stagnated following calving from an adjacent rift.
Sarah S. Thompson, Bernd Kulessa, Adrian Luckman, Jacqueline A. Halpin, Jamin S. Greenbaum, Tyler Pelle, Feras Habbal, Jingxue Guo, Lenneke M. Jong, Jason L. Roberts, Bo Sun, and Donald D. Blankenship
The Cryosphere, 17, 157–174, https://doi.org/10.5194/tc-17-157-2023, https://doi.org/10.5194/tc-17-157-2023, 2023
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We use satellite imagery and ice penetrating radar to investigate the stability of the Shackleton system in East Antarctica. We find significant changes in surface structures across the system and observe a significant increase in ice flow speed (up to 50 %) on the floating part of Scott Glacier. We conclude that knowledge remains woefully insufficient to explain recent observed changes in the grounded and floating regions of the system.
Dominic A. Hodgson, Tom A. Jordan, Neil Ross, Teal R. Riley, and Peter T. Fretwell
The Cryosphere, 16, 4797–4809, https://doi.org/10.5194/tc-16-4797-2022, https://doi.org/10.5194/tc-16-4797-2022, 2022
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This paper describes the drainage (and refill) of a subglacial lake on the Antarctic Peninsula resulting in the collapse of the overlying ice into the newly formed subglacial cavity. It provides evidence of an active hydrological network under the region's glaciers and close coupling between surface climate processes and the base of the ice.
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.
Douglas I. Benn, Adrian Luckman, Jan A. Åström, Anna J. Crawford, Stephen L. Cornford, Suzanne L. Bevan, Thomas Zwinger, Rupert Gladstone, Karen Alley, Erin Pettit, and Jeremy Bassis
The Cryosphere, 16, 2545–2564, https://doi.org/10.5194/tc-16-2545-2022, https://doi.org/10.5194/tc-16-2545-2022, 2022
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Thwaites Glacier (TG), in West Antarctica, is potentially unstable and may contribute significantly to sea-level rise as global warming continues. Using satellite data, we show that Thwaites Eastern Ice Shelf, the largest remaining floating extension of TG, has started to accelerate as it fragments along a shear zone. Computer modelling does not indicate that fragmentation will lead to imminent glacier collapse, but it is clear that major, rapid, and unpredictable changes are underway.
Johannes Oerlemans, Jack Kohler, and Adrian Luckman
The Cryosphere, 16, 2115–2126, https://doi.org/10.5194/tc-16-2115-2022, https://doi.org/10.5194/tc-16-2115-2022, 2022
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Tunabreen is a 26 km long tidewater glacier. It is the most frequently surging glacier in Svalbard, with four documented surges in the past 100 years. We have modelled this glacier to find out how it reacts to future climate change. Careful calibration was done against the observed length record for the past 100 years. For a 50 m increase in the equilibrium line altitude (ELA) the length of the glacier will be shortened by 10 km after about 100 years.
Erin L. McClymont, Michael J. Bentley, Dominic A. Hodgson, Charlotte L. Spencer-Jones, Thomas Wardley, Martin D. West, Ian W. Croudace, Sonja Berg, Darren R. Gröcke, Gerhard Kuhn, Stewart S. R. Jamieson, Louise Sime, and Richard A. Phillips
Clim. Past, 18, 381–403, https://doi.org/10.5194/cp-18-381-2022, https://doi.org/10.5194/cp-18-381-2022, 2022
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Sea ice is important for our climate system and for the unique ecosystems it supports. We present a novel way to understand past Antarctic sea-ice ecosystems: using the regurgitated stomach contents of snow petrels, which nest above the ice sheet but feed in the sea ice. During a time when sea ice was more extensive than today (24 000–30 000 years ago), we show that snow petrel diet had varying contributions of fish and krill, which we interpret to show changing sea-ice distribution.
Karen E. Alley, Christian T. Wild, Adrian Luckman, Ted A. Scambos, Martin Truffer, Erin C. Pettit, Atsuhiro Muto, Bruce Wallin, Marin Klinger, Tyler Sutterley, Sarah F. Child, Cyrus Hulen, Jan T. M. Lenaerts, Michelle Maclennan, Eric Keenan, and Devon Dunmire
The Cryosphere, 15, 5187–5203, https://doi.org/10.5194/tc-15-5187-2021, https://doi.org/10.5194/tc-15-5187-2021, 2021
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We present a 20-year, satellite-based record of velocity and thickness change on the Thwaites Eastern Ice Shelf (TEIS), the largest remaining floating extension of Thwaites Glacier (TG). TG holds the single greatest control on sea-level rise over the next few centuries, so it is important to understand changes on the TEIS, which controls much of TG's flow into the ocean. Our results suggest that the TEIS is progressively destabilizing and is likely to disintegrate over the next few decades.
Suzanne L. Bevan, Adrian J. Luckman, Douglas I. Benn, Susheel Adusumilli, and Anna Crawford
The Cryosphere, 15, 3317–3328, https://doi.org/10.5194/tc-15-3317-2021, https://doi.org/10.5194/tc-15-3317-2021, 2021
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The stability of the West Antarctic ice sheet depends on the behaviour of the fast-flowing glaciers, such as Thwaites, that connect it to the ocean. Here we show that a large ocean-melted cavity beneath Thwaites Glacier has remained stable since it first formed, implying that, in line with current theory, basal melt is now concentrated close to where the ice first goes afloat. We also show that Thwaites Glacier continues to thin and to speed up and that continued retreat is therefore likely.
Suzanne Bevan, Adrian Luckman, Harry Hendon, and Guomin Wang
The Cryosphere, 14, 3551–3564, https://doi.org/10.5194/tc-14-3551-2020, https://doi.org/10.5194/tc-14-3551-2020, 2020
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In February 2020, along with record-breaking high temperatures in the region, satellite images showed that the surface of the largest remaining ice shelf on the Antarctic Peninsula was experiencing a lot of melt. Using archived satellite data we show that this melt was greater than any in the past 40 years. The extreme melt followed unusual weather patterns further north, highlighting the importance of long-range links between the tropics and high latitudes and the impact on ice-shelf stability.
Alex Brisbourne, Bernd Kulessa, Thomas Hudson, Lianne Harrison, Paul Holland, Adrian Luckman, Suzanne Bevan, David Ashmore, Bryn Hubbard, Emma Pearce, James White, Adam Booth, Keith Nicholls, and Andrew Smith
Earth Syst. Sci. Data, 12, 887–896, https://doi.org/10.5194/essd-12-887-2020, https://doi.org/10.5194/essd-12-887-2020, 2020
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Melting of the Larsen C Ice Shelf in Antarctica may lead to its collapse. To help estimate its lifespan we need to understand how the ocean can circulate beneath. This requires knowledge of the geometry of the sub-shelf cavity. New and existing measurements of seabed depth are integrated to produce a map of the ocean cavity beneath the ice shelf. The observed deep seabed may provide a pathway for circulation of warm ocean water but at the same time reduce rapid tidal melt at a critical location.
Christian T. Wild, Oliver J. Marsh, and Wolfgang Rack
The Cryosphere, 13, 3171–3191, https://doi.org/10.5194/tc-13-3171-2019, https://doi.org/10.5194/tc-13-3171-2019, 2019
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In Antarctica, ocean tides control the motion of ice sheets near the coastline as well as melt rates underneath the floating ice. By combining the spatial advantage of rare but highly accurate satellite images with the temporal advantage of tide-prediction models, vertical displacement of floating ice due to ocean tides can now be predicted accurately. This allows the detailed study of ice-flow dynamics in areas that matter the most to the stability of Antarctica's ice sheets.
Suzanne L. Bevan, Adrian J. Luckman, Douglas I. Benn, Tom Cowton, and Joe Todd
The Cryosphere, 13, 2303–2315, https://doi.org/10.5194/tc-13-2303-2019, https://doi.org/10.5194/tc-13-2303-2019, 2019
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Kangerlussuaq Glacier in Greenland retreated significantly in the early 2000s and typified the response of calving glaciers to climate change. Satellite images show that it has recently retreated even further. The current retreat follows the appearance of extremely warm surface waters on the continental shelf during the summer of 2016, which likely entered the fjord and caused the rigid mass of sea ice and icebergs, which normally inhibits calving, to melt and break up.
Agathe Lisé-Pronovost, Michael-Shawn Fletcher, Tom Mallett, Michela Mariani, Richard Lewis, Patricia S. Gadd, Andy I. R. Herries, Maarten Blaauw, Hendrik Heijnis, Dominic A. Hodgson, and Joel B. Pedro
Sci. Dril., 25, 1–14, https://doi.org/10.5194/sd-25-1-2019, https://doi.org/10.5194/sd-25-1-2019, 2019
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We present the first results from scientific drilling at Darwin Crater, a 816 000-year-old meteorite impact crater in Tasmania. The aim was to recover lacustrine sediments in the crater to reconstruct paleoclimate and bridge a time gap in understanding climate change in mid-latitude Australia. The multi-proxy dataset provides clear signatures of alternating glacial and interglacial lithologies, promising for investigating the role of the Southern Hemisphere westerly winds in Pleistocene climate.
Dominic A. Hodgson, Tom A. Jordan, Jan De Rydt, Peter T. Fretwell, Samuel A. Seddon, David Becker, Kelly A. Hogan, Andrew M. Smith, and David G. Vaughan
The Cryosphere, 13, 545–556, https://doi.org/10.5194/tc-13-545-2019, https://doi.org/10.5194/tc-13-545-2019, 2019
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The Brunt Ice Shelf in Antarctica is home to Halley VIa, the latest in a series of six British research stations that have occupied the ice shelf since 1956. A recent rapid growth of rifts in the Brunt Ice Shelf signals the onset of its largest calving event since records began. Here we consider whether this calving event will lead to a new steady state for the ice shelf or an unpinning from the bed, which could predispose it to accelerated flow or collapse.
Dominic A. Hodgson, Kelly Hogan, James M. Smith, James A. Smith, Claus-Dieter Hillenbrand, Alastair G. C. Graham, Peter Fretwell, Claire Allen, Vicky Peck, Jan-Erik Arndt, Boris Dorschel, Christian Hübscher, Andrew M. Smith, and Robert Larter
The Cryosphere, 12, 2383–2399, https://doi.org/10.5194/tc-12-2383-2018, https://doi.org/10.5194/tc-12-2383-2018, 2018
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We studied the Coats Land ice margin, Antarctica, providing a multi-disciplinary geophysical assessment of the ice sheet configuration through its last advance and retreat; a description of the physical constraints on the stability of the past and present ice and future margin based on its submarine geomorphology and ice-sheet geometry; and evidence that once detached from the bed, the ice shelves in this region were predisposed to rapid retreat back to coastal grounding lines.
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.
Suzanne L. Bevan, Adrian Luckman, Bryn Hubbard, Bernd Kulessa, David Ashmore, Peter Kuipers Munneke, Martin O'Leary, Adam Booth, Heidi Sevestre, and Daniel McGrath
The Cryosphere, 11, 2743–2753, https://doi.org/10.5194/tc-11-2743-2017, https://doi.org/10.5194/tc-11-2743-2017, 2017
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Five 90 m boreholes drilled into an Antarctic Peninsula ice shelf show units of ice that are denser than expected and must have formed from refrozen surface melt which has been buried and transported downstream. We used surface flow speeds and snow accumulation rates to work out where and when these units formed. Results show that, as well as recent surface melt, a period of strong melt occurred during the 18th century. Surface melt is thought to be a factor in causing recent ice-shelf break-up.
Penelope How, Douglas I. Benn, Nicholas R. J. Hulton, Bryn Hubbard, Adrian Luckman, Heïdi Sevestre, Ward J. J. van Pelt, Katrin Lindbäck, Jack Kohler, and Wim Boot
The Cryosphere, 11, 2691–2710, https://doi.org/10.5194/tc-11-2691-2017, https://doi.org/10.5194/tc-11-2691-2017, 2017
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This study provides valuable insight into subglacial hydrology and dynamics at tidewater glaciers, which remains a poorly understood area of glaciology. It is a unique study because of the wealth of information provided by simultaneous observations of glacier hydrology at Kronebreen, a tidewater glacier in Svalbard. All these elements build a strong conceptual picture of the glacier's hydrological regime over the 2014 melt season.
Wolfgang Rack, Matt A. King, Oliver J. Marsh, Christian T. Wild, and Dana Floricioiu
The Cryosphere, 11, 2481–2490, https://doi.org/10.5194/tc-11-2481-2017, https://doi.org/10.5194/tc-11-2481-2017, 2017
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Predicting changes of the Antarctic Ice Sheet involves fully understanding ice dynamics at the transition between grounded and floating ice. We map tidal bending of ice by satellite using InSAR, and we use precise GPS measurements with assumptions of tidal elastic bending to better interpret the satellite signal. It allows us to better define the grounding-line position and to refine the shape of tidal flexure profiles.
Peter Kuipers Munneke, Daniel McGrath, Brooke Medley, Adrian Luckman, Suzanne Bevan, Bernd Kulessa, Daniela Jansen, Adam Booth, Paul Smeets, Bryn Hubbard, David Ashmore, Michiel Van den Broeke, Heidi Sevestre, Konrad Steffen, Andrew Shepherd, and Noel Gourmelen
The Cryosphere, 11, 2411–2426, https://doi.org/10.5194/tc-11-2411-2017, https://doi.org/10.5194/tc-11-2411-2017, 2017
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How much snow falls on the Larsen C ice shelf? This is a relevant question, because this ice shelf might collapse sometime this century. To know if and when this could happen, we found out how much snow falls on its surface. This was difficult, because there are only very few measurements. Here, we used data from automatic weather stations, sled-pulled radars, and a climate model to find that melting the annual snowfall produces about 20 cm of water in the NE and over 70 cm in the SW.
Douglas I. Benn, Sarah Thompson, Jason Gulley, Jordan Mertes, Adrian Luckman, and Lindsey Nicholson
The Cryosphere, 11, 2247–2264, https://doi.org/10.5194/tc-11-2247-2017, https://doi.org/10.5194/tc-11-2247-2017, 2017
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This paper provides the first complete view of the drainage system of a large Himalayan glacier, based on ice-cave exploration and satellite image analysis. Drainage tunnels inside glaciers have a major impact on melting rates, by providing lines of weakness inside the ice and potential pathways for melt-water, and play a key role in the response of debris-covered glaciers to sustained periods of negative mass balance.
Louise C. Sime, Dominic Hodgson, Thomas J. Bracegirdle, Claire Allen, Bianca Perren, Stephen Roberts, and Agatha M. de Boer
Clim. Past, 12, 2241–2253, https://doi.org/10.5194/cp-12-2241-2016, https://doi.org/10.5194/cp-12-2241-2016, 2016
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Latitudinal shifts in the Southern Ocean westerly wind jet could explain large observed changes in the glacial to interglacial ocean CO2 inventory. However there is considerable disagreement in modelled deglacial-warming jet shifts. Here multi-model output is used to show that expansion of sea ice during the glacial period likely caused a slight poleward shift and intensification in the westerly wind jet. Issues with model representation of the winds caused much of the previous disagreement.
D. Jansen, A. J. Luckman, A. Cook, S. Bevan, B. Kulessa, B. Hubbard, and P. R. Holland
The Cryosphere, 9, 1223–1227, https://doi.org/10.5194/tc-9-1223-2015, https://doi.org/10.5194/tc-9-1223-2015, 2015
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Within the last year, a large rift in the southern part of the Larsen C Ice Shelf, Antarctic Peninsula, propagated towards the inner part of the ice shelf. In this study we present the development of the rift as derived from remote sensing data and assess the impact of possible calving scenarios on the future stability of the Larsen C Ice Shelf, using a numerical model. We find that the calving front is likely to become unstable after the anticipated calving events.
S. A. Khan, K. K. Kjeldsen, K. H. Kjær, S. Bevan, A. Luckman, A. Aschwanden, A. A. Bjørk, N. J. Korsgaard, J. E. Box, M. van den Broeke, T. M. van Dam, and A. Fitzner
The Cryosphere, 8, 1497–1507, https://doi.org/10.5194/tc-8-1497-2014, https://doi.org/10.5194/tc-8-1497-2014, 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
D. J. Quincey and A. Luckman
The Cryosphere, 8, 571–574, https://doi.org/10.5194/tc-8-571-2014, https://doi.org/10.5194/tc-8-571-2014, 2014
O. J. Marsh, W. Rack, D. Floricioiu, N. R. Golledge, and W. Lawson
The Cryosphere, 7, 1375–1384, https://doi.org/10.5194/tc-7-1375-2013, https://doi.org/10.5194/tc-7-1375-2013, 2013
Related subject area
Discipline: Ice sheets | Subject: Glaciers
Geometric controls of tidewater glacier dynamics
A simple parametrization of mélange buttressing for calving glaciers
A decade of variability on Jakobshavn Isbræ: ocean temperatures pace speed through influence on mélange rigidity
Thomas Frank, Henning Åkesson, Basile de Fleurian, Mathieu Morlighem, and Kerim H. Nisancioglu
The Cryosphere, 16, 581–601, https://doi.org/10.5194/tc-16-581-2022, https://doi.org/10.5194/tc-16-581-2022, 2022
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The shape of a fjord can promote or inhibit glacier retreat in response to climate change. We conduct experiments with a synthetic setup under idealized conditions in a numerical model to study and quantify the processes involved. We find that friction between ice and fjord is the most important factor and that it is possible to directly link ice discharge and grounding line retreat to fjord topography in a quantitative way.
Tanja Schlemm and Anders Levermann
The Cryosphere, 15, 531–545, https://doi.org/10.5194/tc-15-531-2021, https://doi.org/10.5194/tc-15-531-2021, 2021
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Ice loss from Greenland and Antarctica is often cloaked by a mélange of icebergs and sea ice. Here we provide a simple method to parametrize the resulting back stress on the ice flow for large-scale projection models.
Ian Joughin, David E. Shean, Benjamin E. Smith, and Dana Floricioiu
The Cryosphere, 14, 211–227, https://doi.org/10.5194/tc-14-211-2020, https://doi.org/10.5194/tc-14-211-2020, 2020
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Jakobshavn Isbræ, considered to be Greenland's fastest glacier, has varied its speed and thinned dramatically since the 1990s. Here we examine the glacier's behaviour over the last decade to better understand this behaviour. We find that when the floating ice (mélange) in front of the glacier freezes in place during the winter, it can control the glacier's speed and thinning rate. A recently colder ocean has strengthened this mélange, allowing the glacier to recoup some of its previous losses.
Cited articles
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Benn, D. I., Luckman, A., Åström, J. A., Crawford, A. J., Cornford, S. L., Bevan, S. L., Zwinger, T., Gladstone, R., Alley, K., Pettit, E., and Bassis, J.: Rapid fragmentation of Thwaites Eastern Ice Shelf, The Cryosphere, 16, 2545–2564, https://doi.org/10.5194/tc-16-2545-2022, 2022.
De Rydt, J., Gudmundsson, G. H., Nagler, T., Wuite, J., and King, E. C.: Recent rift formation and impact on the structural integrity of the Brunt Ice Shelf, East Antarctica, The Cryosphere, 12, 505–520, https://doi.org/10.5194/tc-12-505-2018, 2018.
De Rydt, J., Gudmundsson, G. H., Nagler, T., and Wuite, J.: Calving cycle of the Brunt Ice Shelf, Antarctica, driven by changes in ice shelf geometry, The Cryosphere, 13, 2771–2787, https://doi.org/10.5194/tc-13-2771-2019, 2019.
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Gudmundsson, G. H., De Rydt, J., and Nagler, T.: Five decades of strong temporal variability in the flow of Brunt Ice Shelf, Antarctica, J. Glaciol., 63, 164–175, 2017.
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Co-editor-in-chief
The ongoing acceleration and disintegration of Antarctic ice shelves is a topic of keen interest to the scientific community. Recent years have seen multiple calving events, some of which have produced large icebergs. In this study, the effect of such a large iceberg-calving event is studied through remote sensing data. The authors show how the break-off of the iceberg led to significant ice speed-up, demonstrating the important effect of calving on the ice shelves.
The ongoing acceleration and disintegration of Antarctic ice shelves is a topic of keen interest...
Short summary
The Brunt Ice Shelf has accelerated rapidly after calving an iceberg in January 2023. A decade of GPS data show that the rate of acceleration in August 2023 was 30 times higher than before calving, and velocity has doubled in 6 months. Satellite velocity maps show the extent of the change. The acceleration is due to loss of contact between the ice shelf and a pinning point known as the McDonald Ice Rumples. The observations highlight how iceberg calving can directly impact ice shelves.
The Brunt Ice Shelf has accelerated rapidly after calving an iceberg in January 2023. A decade...