Articles | Volume 14, issue 12
10 Dec 2020
Research article | 10 Dec 2020
Subglacial lakes and hydrology across the Ellsworth Subglacial Highlands, West Antarctica
Felipe Napoleoni et al.
No articles found.
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,Short summary
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.
Alice C. Frémand, Julien A. Bodart, Tom A. Jordan, Fausto Ferraccioli, Carl Robinson, Hugh F. J. Corr, Helen J. Peat, Robert G. Bingham, and David G. Vaughan
Earth Syst. Sci. Data Discuss.,
Preprint under review for ESSDShort summary
This paper presents the release of large swaths of airborne geophysical data (including gravity, magnetics and radar) acquired between 1994 and 2020. This includes a total of 64 datasets from 24 different surveys, amounting to > 30 % of coverage over the Antarctic Ice Sheet. The paper discusses how this data was acquired and processed, and presents the methods used to standardise and publish the data in an interactive and reproducible manner.
Jonathan Oberreuter, Edwin Badillo-Rivera, Edwin Loarte, Katy Medina, Alejo Cochachin, and José Uribe
Earth Syst. Sci. Data Discuss.,
Manuscript not accepted for further reviewShort summary
We present a representative set of data of interpreted ice thickness and ice surface elevation of the ablation area of the Artesonraju glacier between 2012 and 2020. The results show a maximum depth of 235 ± 18 m and a decreasing mean depth ranging from 134 ± 18 m in 2013 to 110 ± 18 m in 2020. Additionally, we estimate a mean ice thickness change rate of −4.2 ± 3.2 m yr−1 between 2014 and 2020, which is in agreement with the elevation change in the same period of −3.2 ± 0.2 m yr−1.
Jamey Stutz, Andrew Mackintosh, Kevin Norton, Ross Whitmore, Carlo Baroni, Stewart S. R. Jamieson, Richard S. Jones, Greg Balco, Maria Cristina Salvatore, Stefano Casale, Jae Il Lee, Yeong Bae Seong, Robert McKay, Lauren J. Vargo, Daniel Lowry, Perry Spector, Marcus Christl, Susan Ivy Ochs, Luigia Di Nicola, Maria Iarossi, Finlay Stuart, and Tom Woodruff
The Cryosphere, 15, 5447–5471,Short summary
Understanding the long-term behaviour of ice sheets is essential to projecting future changes due to climate change. In this study, we use rocks deposited along the margin of the David Glacier, one of the largest glacier systems in the world, to reveal a rapid thinning event initiated over 7000 years ago and endured for ~ 2000 years. Using physical models, we show that subglacial topography and ocean heat are important drivers for change along this sector of the Antarctic Ice Sheet.
Alex M. Brisbourne, Michael Kendall, Sofia-Katerina Kufner, Thomas S. Hudson, and Andrew M. Smith
The Cryosphere, 15, 3443–3458,Short summary
How ice sheets flowed in the past is written into the structure and texture of the ice sheet itself. Measuring this structure and properties of the ice can help us understand the recent behaviour of the ice sheets. We use a relatively new technique, not previously attempted in Antarctica, to measure the seismic vibrations of a fibre optic cable down a borehole. We demonstrate the potential of this technique to unravel past ice flow and see hints of these complex signals from the ice flow itself.
Elizabeth Ruth Thomas, Guisella Gacitúa, Joel B. Pedro, Amy Constance Faith King, Bradley Markle, Mariusz Potocki, and Dorothea Elisabeth Moser
The Cryosphere, 15, 1173–1186,Short summary
Here we present the first-ever radar and ice core data from the sub-Antarctic islands of Bouvet Island, Peter I Island, and Young Island. These islands have the potential to record past climate in one of the most data-sparse regions on earth. Despite their northerly location, surface melting is generally low, and the upper layer of the ice at most sites is undisturbed. We estimate that a 100 m ice core drilled on these islands could capture climate over the past 100–200 years.
Bertie W. J. Miles, Jim R. Jordan, Chris R. Stokes, Stewart S. R. Jamieson, G. Hilmar Gudmundsson, and Adrian Jenkins
The Cryosphere, 15, 663–676,Short summary
We provide a historical overview of changes in Denman Glacier's flow speed, structure and calving events since the 1960s. Based on these observations, we perform a series of numerical modelling experiments to determine the likely cause of Denman's acceleration since the 1970s. We show that grounding line retreat, ice shelf thinning and the detachment of Denman's ice tongue from a pinning point are the most likely causes of the observed acceleration.
Guisella Gacitúa, Christoph Schneider, Jorge Arigony, Inti González, Ricardo Jaña, and Gino Casassa
Earth Syst. Sci. Data, 13, 231–236,Short summary
We performed the first successful ice thickness measurements using terrestrial ground-penetrating radar in the ablation area of Schiaparelli Glacier (Cordillera Darwin, Tierra del Fuego, Chile). Data are fundamental to understand glaciers dynamics, constrain ice dynamical modelling, and predict glacier evolution. Results show a valley-shaped bedrock below current sea level; thus further retreat of Schiaparelli Glacier will probably lead to an enlarged and strongly over-deepened proglacial lake.
William D. Smith, Stuart A. Dunning, Stephen Brough, Neil Ross, and Jon Telling
Earth Surf. Dynam., 8, 1053–1065,Short summary
Glacial landslides are difficult to detect and likely underestimated due to rapid covering or dispersal. Without improved detection rates we cannot constrain their impact on glacial dynamics or their potential climatically driven increases in occurrence. Here we present a new open-access tool (GERALDINE) that helps a user detect 92 % of these events over the past 38 years on a global scale. We demonstrate its ability by identifying two new, large glacial landslides in the Hayes Range, Alaska.
Jennifer F. Arthur, Chris R. Stokes, Stewart S. R. Jamieson, J. Rachel Carr, and Amber A. Leeson
The Cryosphere, 14, 4103–4120,Short summary
Surface meltwater lakes can flex and fracture ice shelves, potentially leading to ice shelf break-up. A long-term record of lake evolution on Shackleton Ice Shelf is produced using optical satellite imagery and compared to surface air temperature and modelled surface melt. The results reveal that lake clustering on the ice shelf is linked to melt-enhancing feedbacks. Peaks in total lake area and volume closely correspond with intense snowmelt events rather than with warmer seasonal temperatures.
Xiangbin Cui, Hafeez Jeofry, Jamin S. Greenbaum, Jingxue Guo, Lin Li, Laura E. Lindzey, Feras A. Habbal, Wei Wei, Duncan A. Young, Neil Ross, Mathieu Morlighem, Lenneke M. Jong, Jason L. Roberts, Donald D. Blankenship, Sun Bo, and Martin J. Siegert
Earth Syst. Sci. Data, 12, 2765–2774,Short summary
We present a topographic digital elevation model (DEM) for Princess Elizabeth Land (PEL), East Antarctica. The DEM covers an area of approximately 900 000 km2 and was built from radio-echo sounding data collected in four campaigns since 2015. Previously, to generate the Bedmap2 topographic product, PEL’s bed was characterised from low-resolution satellite gravity data across an otherwise large (>200 km wide) data-free zone.
Neil Ross, Hugh Corr, and Martin Siegert
The Cryosphere, 14, 2103–2114,Short summary
Using airborne ice-penetrating radar we investigated the physical properties and structure of the West Antarctic Ice Sheet. Ice deep beneath the Institute Ice Stream has prominent layers with physical properties distinct from those around them and which are heavily folded like geological layers. In turn, these folds influence the present-day flow of the ice sheet, with implications for how computer models are used to simulate ice sheet flow and behaviour in a warming world.
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,Short summary
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.
Stephen J. Livingstone, Andrew J. Sole, Robert D. Storrar, Devin Harrison, Neil Ross, and Jade Bowling
The Cryosphere, 13, 2789–2796,Short summary
We report three new subglacial lakes close to the ice sheet margin of West Greenland. The lakes drained and refilled once each between 2009 and 2017, with two lakes draining in < 1 month during August 2014 and August 2015. The 2015 drainage caused a ~ 1-month down-glacier slowdown in ice flow and flooded the foreland, significantly modifying the braided river and depositing up to 8 m of sediment. These subglacial lakes offer accessible targets for future investigations and exploration.
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,Short summary
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.
Bertie W. J. Miles, Chris R. Stokes, and Stewart S. R. Jamieson
The Cryosphere, 12, 3123–3136,Short summary
Cook Glacier, as one of the largest in East Antarctica, may have made significant contributions to sea level during past warm periods. However, despite its potential importance there have been no long-term observations of its velocity. Here, through estimating velocity and ice front position from satellite imagery and aerial photography we show that there have been large previously undocumented changes in the velocity of Cook Glacier in response to ice shelf loss and a subglacial drainage event.
Thomas M. Jordan, Christopher N. Williams, Dustin M. Schroeder, Yasmina M. Martos, Michael A. Cooper, Martin J. Siegert, John D. Paden, Philippe Huybrechts, and Jonathan L. Bamber
The Cryosphere, 12, 2831–2854,Short summary
Here, via analysis of radio-echo sounding data, we place a new observational constraint upon the basal water distribution beneath the Greenland Ice Sheet. In addition to the outlet glaciers, we demonstrate widespread water storage in the northern and eastern ice-sheet interior, a notable feature being a "corridor" of basal water extending from NorthGRIP to Petermann Glacier. The basal water distribution and its relationship with basal temperature provides a new constraint for numerical models.
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,Short summary
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.
Damon Davies, Robert G. Bingham, Edward C. King, Andrew M. Smith, Alex M. Brisbourne, Matteo Spagnolo, Alastair G. C. Graham, Anna E. Hogg, and David G. Vaughan
The Cryosphere, 12, 1615–1628,Short summary
This paper investigates the dynamics of ice stream beds using repeat geophysical surveys of the bed of Pine Island Glacier, West Antarctica; 60 km of the bed was surveyed, comprising the most extensive repeat ground-based geophysical surveys of an Antarctic ice stream; 90 % of the surveyed bed shows no significant change despite the glacier increasing in speed by up to 40 % over the last decade. This result suggests that ice stream beds are potentially more stable than previously suggested.
Hafeez Jeofry, Neil Ross, Hugh F. J. Corr, Jilu Li, Mathieu Morlighem, Prasad Gogineni, and Martin J. Siegert
Earth Syst. Sci. Data, 10, 711–725,Short summary
Accurately characterizing the complexities of the ice-sheet dynamic specifically close to the grounding line across the Weddell Sea (WS) sector in the ice-sheet models provides challenges to the scientific community. Our main objective is to comprehend these complexities, adding accuracy to the projection of future ice-sheet dynamics. Therefore, we have developed a new bed elevation digital elevation model across the WS sector, which will be of value to ice-sheet modelling experiments.
Frédéric Parrenin, Marie G. P. Cavitte, Donald D. Blankenship, Jérôme Chappellaz, Hubertus Fischer, Olivier Gagliardini, Valérie Masson-Delmotte, Olivier Passalacqua, Catherine Ritz, Jason Roberts, Martin J. Siegert, and Duncan A. Young
The Cryosphere, 11, 2427–2437,Short summary
The oldest dated deep ice core drilled in Antarctica has been retrieved at EPICA Dome C (EDC), reaching ~ 800 000 years. Obtaining an older palaeoclimatic record from Antarctica is one of the greatest challenges of the ice core community. Here, we estimate the age of basal ice in the Dome C area. We find that old ice (> 1.5 Myr) likely exists in two regions a few tens of kilometres away from EDC:
Little Dome C Patchand
Claudio Bravo, Thomas Loriaux, Andrés Rivera, and Ben W. Brock
Hydrol. Earth Syst. Sci., 21, 3249–3266,Short summary
We present an analysis of meteorological conditions and melt for Universidad Glacier in central Chile. This glacier is characterized by high melt rates over the ablation season, representing a mean contribution of between 10 and 13 % of the total runoff observed in the upper Tinguiririca Basin during the November 2009 to March 2010 period. Few studies have quantified the glacier melt contribution to river runoff in Chile, and this work represents a new precedent for the Andes.
Thomas M. Jordan, Michael A. Cooper, Dustin M. Schroeder, Christopher N. Williams, John D. Paden, Martin J. Siegert, and Jonathan L. Bamber
The Cryosphere, 11, 1247–1264,Short summary
Using radio-echo sounding data from northern Greenland, we demonstrate that subglacial roughness exhibits self-affine (fractal) scaling behaviour. This enables us to assess topographic control upon the bed-echo waveform, and explain the spatial distribution of the degree of scattering (specular and diffuse reflections). Via comparison with a prediction for the basal thermal state (thawed and frozen regions of the bed) we discuss the consequences of our study for basal water discrimination.
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,Short summary
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.
Bertie W. J. Miles, Chris R. Stokes, and Stewart S. R. Jamieson
The Cryosphere, 11, 427–442,Short summary
We observe a large simultaneous calving event in Porpoise Bay, East Antarctica, where ~ 2900 km2 of ice was removed from floating glacier tongues between January and April 2007. This event was caused by the break-up of the multi-year sea ice usually occupies the bay, which we link to climatic forcing. We also observe a similar large calving event in March 2016 (~ 2200 km2), which we link to the long-term calving cycle of Holmes (West) Glacier.
Christopher N. Williams, Stephen L. Cornford, Thomas M. Jordan, Julian A. Dowdeswell, Martin J. Siegert, Christopher D. Clark, Darrel A. Swift, Andrew Sole, Ian Fenty, and Jonathan L. Bamber
The Cryosphere, 11, 363–380,Short summary
Knowledge of ice sheet bed topography and surrounding sea floor bathymetry is integral to the understanding of ice sheet processes. Existing elevation data products for Greenland underestimate fjord bathymetry due to sparse data availability. We present a new method to create physically based synthetic fjord bathymetry to fill these gaps, greatly improving on previously available datasets. This will assist in future elevation product development until further observations become available.
T. M. Jordan, J. L. Bamber, C. N. Williams, J. D. Paden, M. J. Siegert, P. Huybrechts, O. Gagliardini, and F. Gillet-Chaulet
The Cryosphere, 10, 1547–1570,Short summary
Ice penetrating radar enables determination of the basal properties of ice sheets. Existing algorithms assume stationarity in the attenuation rate, which is not justifiable at an ice sheet scale. We introduce the first ice-sheet-wide algorithm for radar attenuation that incorporates spatial variability, using the temperature field from a numerical model as an initial guess. The study is a step toward ice-sheet-wide data products for basal properties and evaluation of model temperature fields.
Edward C. King, Hamish D. Pritchard, and Andrew M. Smith
Earth Syst. Sci. Data, 8, 151–158,Short summary
Large, fast-moving glaciers create long, linear mounds of sediments covering large areas. Understanding how these features form has been hampered by a lack of data from the bed of modern-day ice sheets. We give a detailed view of the landscape beneath an Antarctic glacier called Rutford Ice Stream. We towed a radar system back and forth across the glacier to measure the ice thickness every few metres. This is the first place such a highly detailed view of the sub-ice landscape has been created.
Tessa R. Vance, Jason L. Roberts, Andrew D. Moy, Mark A. J. Curran, Carly R. Tozer, Ailie J. E. Gallant, Nerilie J. Abram, Tas D. van Ommen, Duncan A. Young, Cyril Grima, Don D. Blankenship, and Martin J. Siegert
Clim. Past, 12, 595–610,Short summary
This study details a systematic approach to finding a new high-resolution East Antarctic ice core site. The study initially outlines seven criteria that a new site must fulfil, encompassing specific accumulation, ice dynamics and atmospheric circulation aspects. We then use numerous techniques including Antarctic surface mass balance syntheses, ground-truthing of satellite data by airborne radar surveys and reanalysis products to pinpoint promising regions.
S. L. Cornford, D. F. Martin, A. J. Payne, E. G. Ng, A. M. Le Brocq, R. M. Gladstone, T. L. Edwards, S. R. Shannon, C. Agosta, M. R. van den Broeke, H. H. Hellmer, G. Krinner, S. R. M. Ligtenberg, R. Timmermann, and D. G. Vaughan
The Cryosphere, 9, 1579–1600,Short summary
We used a high-resolution ice sheet model capable of resolving grounding line dynamics (BISICLES) to compute responses of the major West Antarctic ice streams to projections of ocean and atmospheric warming. This is computationally demanding, and although other groups have considered parts of West Antarctica, we think this is the first calculation for the whole region at the sub-kilometer resolution that we show is required.
P. R. Holland, A. Brisbourne, H. F. J. Corr, D. McGrath, K. Purdon, J. Paden, H. A. Fricker, F. S. Paolo, and A. H. Fleming
The Cryosphere, 9, 1005–1024,Short summary
Antarctic Peninsula ice shelves have collapsed in recent decades. The surface of Larsen C Ice Shelf is lowering, but the cause of this has not been understood. This study uses eight radar surveys to show that the lowering is caused by both ice loss and a loss of air from the ice shelf's snowpack. At least two different processes are causing the lowering. The stability of Larsen C may be at risk from an ungrounding of Bawden Ice Rise or ice-front retreat past a 'compressive arch' in strain rates.
K. C. Rose, N. Ross, T. A. Jordan, R. G. Bingham, H. F. J. Corr, F. Ferraccioli, A. M. Le Brocq, D. M. Rippin, and M. J. Siegert
Earth Surf. Dynam., 3, 139–152,Short summary
We use ice-penetrating-radar data to identify a laterally continuous, gently sloping topographic block, comprising two surfaces separated by a distinct break in slope, preserved beneath the Institute and Möller ice streams, West Antarctica. We interpret these features as extensive erosion surfaces, showing that ancient (pre-glacial) surfaces can be preserved at low elevations beneath ice sheets. Different erosion regimes (e.g. fluvial and marine) may have formed these surfaces.
A. P. Wright, A. M. Le Brocq, S. L. Cornford, R. G. Bingham, H. F. J. Corr, F. Ferraccioli, T. A. Jordan, A. J. Payne, D. M. Rippin, N. Ross, and M. J. Siegert
The Cryosphere, 8, 2119–2134,
A. Rivera, R. Zamora, J. A. Uribe, R. Jaña, and J. Oberreuter
The Cryosphere, 8, 1445–1456,
T. Howard, A. K. Pardaens, J. L. Bamber, J. Ridley, G. Spada, R. T. W. L. Hurkmans, J. A. Lowe, and D. Vaughan
Ocean Sci., 10, 473–483,
M. J. Siegert, N. Ross, H. Corr, B. Smith, T. Jordan, R. G. Bingham, F. Ferraccioli, D. M. Rippin, and A. Le Brocq
The Cryosphere, 8, 15–24,
A. M. Brisbourne, A. M. Smith, E. C. King, K. W. Nicholls, P. R. Holland, and K. Makinson
The Cryosphere, 8, 1–13,
M. Schwikowski, M. Schläppi, P. Santibañez, A. Rivera, and G. Casassa
The Cryosphere, 7, 1635–1644,
P. Dutrieux, D. G. Vaughan, H. F. J. Corr, A. Jenkins, P. R. Holland, I. Joughin, and A. H. Fleming
The Cryosphere, 7, 1543–1555,
A. K. Melkonian, M. J. Willis, M. E. Pritchard, A. Rivera, F. Bown, and S. A. Bernstein
The Cryosphere, 7, 823–839,
P. Fretwell, H. D. Pritchard, D. G. Vaughan, J. L. Bamber, N. E. Barrand, R. Bell, C. Bianchi, R. G. Bingham, D. D. Blankenship, G. Casassa, G. Catania, D. Callens, H. Conway, A. J. Cook, H. F. J. Corr, D. Damaske, V. Damm, F. Ferraccioli, R. Forsberg, S. Fujita, Y. Gim, P. Gogineni, J. A. Griggs, R. C. A. Hindmarsh, P. Holmlund, J. W. Holt, R. W. Jacobel, A. Jenkins, W. Jokat, T. Jordan, E. C. King, J. Kohler, W. Krabill, M. Riger-Kusk, K. A. Langley, G. Leitchenkov, C. Leuschen, B. P. Luyendyk, K. Matsuoka, J. Mouginot, F. O. Nitsche, Y. Nogi, O. A. Nost, S. V. Popov, E. Rignot, D. M. Rippin, A. Rivera, J. Roberts, N. Ross, M. J. Siegert, A. M. Smith, D. Steinhage, M. Studinger, B. Sun, B. K. Tinto, B. C. Welch, D. Wilson, D. A. Young, C. Xiangbin, and A. Zirizzotti
The Cryosphere, 7, 375–393,
M. G. P. Cavitte, D. D. Blankenship, D. A. Young, M. J. Siegert, and E. Le Meur
The Cryosphere Discuss.,
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,
Related subject area
Discipline: Ice sheets | Subject: Subglacial ProcessesRadar sounding survey over Devon Ice Cap indicates the potential for a diverse hypersaline subglacial hydrological environmentGrounding zone subglacial properties from calibrated active-source seismic methodsThe role of electrical conductivity in radar wave reflection from glacier bedsReview article: Geothermal heat flow in Antarctica: current and future directionsExceptionally high heat flux needed to sustain the Northeast Greenland Ice StreamSubglacial roughness of the Greenland Ice Sheet: relationship with contemporary ice velocity and geologySubglacial hydrological control on flow of an Antarctic Peninsula palaeo-ice stream
Anja Rutishauser, Donald D. Blankenship, Duncan A. Young, Natalie S. Wolfenbarger, Lucas H. Beem, Mark L. Skidmore, Ashley Dubnick, and Alison S. Criscitiello
The Cryosphere, 16, 379–395,Short summary
Recently, a hypersaline subglacial lake complex was hypothesized to lie beneath Devon Ice Cap, Canadian Arctic. Here, we present results from a follow-on targeted aerogeophysical survey. Our results support the evidence for a hypersaline subglacial lake and reveal an extensive brine network, suggesting more complex subglacial hydrological conditions than previously inferred. This hypersaline system may host microbial habitats, making it a compelling analog for bines on other icy worlds.
Huw J. Horgan, Laurine van Haastrecht, Richard B. Alley, Sridhar Anandakrishnan, Lucas H. Beem, Knut Christianson, Atsuhiro Muto, and Matthew R. Siegfried
The Cryosphere, 15, 1863–1880,Short summary
The grounding zone marks the transition from a grounded ice sheet to a floating ice shelf. Like Earth's coastlines, the grounding zone is home to interactions between the ocean, fresh water, and geology but also has added complexity and importance due to the overriding ice. Here we use seismic surveying – sending sound waves down through the ice – to image the grounding zone of Whillans Ice Stream in West Antarctica and learn more about the nature of this important transition zone.
Slawek M. Tulaczyk and Neil T. Foley
The Cryosphere, 14, 4495–4506,Short summary
Much of what we know about materials hidden beneath glaciers and ice sheets on Earth has been interpreted using radar reflection from the ice base. A common assumption is that electrical conductivity of the sub-ice materials does not influence the reflection strength and that the latter is controlled only by permittivity, which depends on the fraction of water in these materials. Here we argue that sub-ice electrical conductivity should be generally considered when interpreting radar records.
Alex Burton-Johnson, Ricarda Dziadek, and Carlos Martin
The Cryosphere, 14, 3843–3873,Short summary
The Antarctic ice sheet is the largest source for sea level rise. However, one key control on ice sheet flow remains poorly constrained: the effect of heat from the rocks beneath the ice sheet (known as
geothermal heat flow). Although this may not seem like a lot of heat, beneath thick, slow ice this heat can control how well the ice flows and can lead to melting of the ice sheet. We discuss the methods used to estimate this heat, compile existing data, and recommend future research.
Silje Smith-Johnsen, Basile de Fleurian, Nicole Schlegel, Helene Seroussi, and Kerim Nisancioglu
The Cryosphere, 14, 841–854,Short summary
The Northeast Greenland Ice Stream (NEGIS) drains a large part of Greenland and displays fast flow far inland. However, the flow pattern is not well represented in ice sheet models. The fast flow has been explained by abnormally high geothermal heat flux. The heat melts the base of the ice sheet and the water produced may lubricate the bed and induce fast flow. By including high geothermal heat flux and a hydrology model, we successfully reproduce NEGIS flow pattern in an ice sheet model.
Michael A. Cooper, Thomas M. Jordan, Dustin M. Schroeder, Martin J. Siegert, Christopher N. Williams, and Jonathan L. Bamber
The Cryosphere, 13, 3093–3115,
Robert D. Larter, Kelly A. Hogan, Claus-Dieter Hillenbrand, James A. Smith, Christine L. Batchelor, Matthieu Cartigny, Alex J. Tate, James D. Kirkham, Zoë A. Roseby, Gerhard Kuhn, Alastair G. C. Graham, and Julian A. Dowdeswell
The Cryosphere, 13, 1583–1596,Short summary
We present high-resolution bathymetry data that provide the most complete and detailed imagery of any Antarctic palaeo-ice stream bed. These data show how subglacial water was delivered to and influenced the dynamic behaviour of the ice stream. Our observations provide insights relevant to understanding the behaviour of modern ice streams and forecasting the contributions that they will make to future sea level rise.
An, M., Wiens, D. A., Zhao, Y., Feng, M., Nyblade, A., Kanao, M., Li, Y., Maggi, A., and Lévêque, J.-J.: Temperature, lithosphere-asthenosphere boundary, and heat flux beneath the Antarctic Plate inferred from seismic velocities, J. Geophys. Res.-Sol. Ea., 120, 8720–8742, https://doi.org/10.1002/2015JB011917, 2015. a
Anandakrishnan, S. and Alley, R. B.: Stagnation of ice stream C, West Antarctica by water piracy, Geophys. Res. Lett., 24, 265–268, 1997. a
Bell, R. E., Ferraccioli, F., Creyts, T. T., Braaten, D., Corr, H., Das, I., Damaske, D., Frearson, N., Jordan, T., Rose, K., Studinger, M., and Wolovick, M.: Widespread Persistent Thickening of the East Antarctic Ice Sheet by Freezing from the Base, Science, 331, 1592–1595, https://doi.org/10.1126/science.1200109, 2011. a
Corr, H., Moore, J. C., and Nicholls, K. W.: Radar absorption due to impurities in Antarctic ice, Geophys. Res. Lett., 20, 1071–1074, 1993. a
Cuffey, K. M. and Paterson, W. S. B.: The physics of glaciers, Academic Press, 2010. a
Fretwell, P., Pritchard, H. D., Vaughan, D. G., Bamber, J. L., Barrand, N. E., Bell, R., Bianchi, C., Bingham, R. G., Blankenship, D. D., Casassa, G., Catania, G., Callens, D., Conway, H., Cook, A. J., Corr, H. F. J., Damaske, D., Damm, V., Ferraccioli, F., Forsberg, R., Fujita, S., Gim, Y., Gogineni, P., Griggs, J. A., Hindmarsh, R. C. A., Holmlund, P., Holt, J. W., Jacobel, R. W., Jenkins, A., Jokat, W., Jordan, T., King, E. C., Kohler, J., Krabill, W., Riger-Kusk, M., Langley, K. A., Leitchenkov, G., Leuschen, C., Luyendyk, B. P., Matsuoka, K., Mouginot, J., Nitsche, F. O., Nogi, Y., Nost, O. A., Popov, S. V., Rignot, E., Rippin, D. M., Rivera, A., Roberts, J., Ross, N., Siegert, M. J., Smith, A. M., Steinhage, D., Studinger, M., Sun, B., Tinto, B. K., Welch, B. C., Wilson, D., Young, D. A., Xiangbin, C., and Zirizzotti, A.: Bedmap2: improved ice bed, surface and thickness datasets for Antarctica, The Cryosphere, 7, 375–393, https://doi.org/10.5194/tc-7-375-2013, 2013. a, b
Gudlaugsson, E., Humbert, A., Andreassen, K., Clason, C. C., Kleiner, T., and Beyer, S.: Eurasian ice-sheet dynamics and sensitivity to subglacial hydrology, J. Glaciol., 63, 556–564, 2017. a
Jordan, T. A., Ferraccioli, F., Ross, N., Corr, H. F., Leat, P. T., Bingham, R. G., Rippin, D. M., le Brocq, A., and Siegert, M. J.: Inland extent of the Weddell Sea Rift imaged by new aerogeophysical data, Tectonophysics, 585, 137–160, 2013. a
Leat, P. T., Jordan, T. A., Flowerdew, M. J., Riley, T. R., Ferraccioli, F., and Whitehouse, M. J.: Jurassic high heat production granites associated with the Weddell Sea rift system, Antarctica, Tectonophysics, 722, 249–264, 2018. a
Lythe, M. B. and Vaughan, D. G.: BEDMAP: A new ice thickness and subglacial topographic model of Antarctica, J. Geophys. Res.-Sol. Ea., 106, 11335–11351, 2001. a
Matsuoka, K., MacGregor, J. A., and Pattyn, F.: Predicting radar attenuation within the Antarctic ice sheet, Earth Planet. Sci. Lett., 359, 173–183, 2012. a
Maule, C. F., Purucker, M. E., Olsen, N., and Mosegaard, K.: Heat flux anomalies in Antarctica revealed by satellite magnetic data, Science, 309, 464–467, 2005. a
Napoleoni, F., Jamieson, S. S. R., Ross, N., Bentley, M., Rivera, A., Smith, A., Siegert, M., Paxman, G., Gacitúa, G., Uribe, J., Zamora, R., Brisbourne, A., and Vaughan, D.: Subglacial lakes and hydrology across the Ellsworth Subglacial Highlands, West Antarctica, 1977–2017 (Version 1.0), UK Polar Data Centre, Natural Environment Research Council, available at: https://data.bas.ac.uk/full-record.php?id=GB/NERC/BAS/PDC/01401, last access: 16 November 2020. a
Paxman, G., Jamieson, S., Ferraccioli, F., Bentley, M., Forsberg, R., Ross, N., Watts, A., F.J. Corr, H., and Jordan, T.: Uplift and tilting of the Shackleton Range in East Antarctica driven by glacial erosion and normal faulting: Flexural Uplift of the Shackleton Range, J. Geophys. Res.-Sol. Ea., 122, 2390–2408, https://doi.org/10.1002/2016JB013841, 2017. a
Paxman, G. J., Jamieson, S. S., Hochmuth, K., Gohl, K., Bentley, M. J., Leitchenkov, G., and Ferraccioli, F.: Reconstructions of Antarctic topography since the Eocene–Oligocene boundary, Palaeogeography, Palaeoclimatology, Palaeoecology, 535, 109346, https://doi.org/10.1016/j.palaeo.2019.109346, 2019. a
Robin, G. de Q., Swithinbank, C., Smith, B. M. E.: Radio echo exploration of the Antarctic ice sheet, in: International Symposium on Antarctic Glaciological Exploration (ISAGE), edited by: Gow, A. J., Keeler, C., Langway, C. C., Weeks, W. F., Hanover, New Hampshire, 3–7 September 1968, Gentbrugge, International Association of Scientific Hydrology, (IASH Publication, 86), 97–115, 1970. a, b
Schroeder, D. M., Blankenship, D. D., and Young, D. A.: Evidence for a water system transition beneath Thwaites Glacier, West Antarctica, P. Natl. Acad. Sci. USA, 110, 12225–12228, 2013. a
Schroeder, D. M., Seroussi, H., Chu, W., and Young, D. A.: Adaptively constraining radar attenuation and temperature across the Thwaites Glacier catchment using bed echoes, J. Glaciol., 62, 1075–1082, 2016. a
Shapiro, N. M. and Ritzwoller, M. H.: Inferring surface heat flux distributions guided by a global seismic model: particular application to Antarctica, Earth Planet. Sci. Lett., 223, 213–224, 2004. a
Siegert, M. J.: Lakes Beneath the Ice Sheet: The Occurrence, Analysis, and Future Exploration of Lake Vostok and Other Antarctic Subglacial Lakes, Annu. Rev. Earth Pl. Sc., 33, 215–245, https://doi.org/10.1146/annurev.earth.33.092203.122725, 2005. a, b, c
Siegert, M. J. and Bamber, J. L.: Subglacial water at the heads of Antarctic ice-stream tributaries, J. Glaciol., 46, 702–703, 2000. a
Siegert, M. J., Clarke, R. J., Mowlem, M., Ross, N., Hill, C. S., Tait, A., Hodgson, D., Parnell, J., Tranter, M., Pearce, D., Bentley, M. J., Cockell, C., Tsaloglou, M.-N., Smith, A., Woodward, J., Brito, M. P., and Waugh, E.: Clean access, measurement, and sampling of Ellsworth Subglacial Lake: A method for exploring deep Antarctic subglacial lake environments, Rev. Geophys., 50, 1–40, https://doi.org/10.1029/2011RG000361, 2012. a, b, c
Siegert, M. J., Kingslake, J., Ross, N., Whitehouse, P. L., Woodward, J., Jamieson, S. S. R., Bentley, M. J., Winter, K., Wearing, M., Hein, A. S., Jeofry, H., and Sugden, D. E.: Major Ice Sheet Change in the Weddell Sea Sector of West Antarctica Over the Last 5000 Years, Rev. Geophys., 57, 1197–1223, https://doi.org/10.1029/2019RG000651, 2019. a
Stearns, L. A., Smith, B. E., and Hamilton, G. S.: Increased flow speed on a large East Antarctic outlet glacier caused by subglacial floods, Nat. Geosci., 1, 827, https://doi.org/10.1038/ngeo356, 2008. a
Stenoien, M. D. and Bentley, C. R.: Pine Island Glacier, Antarctica: A study of the catchment using interferometric synthetic aperture radar measurements and radar altimetry, J. Geophys. Res.-Sol. Ea., 105, 21761–21779, 2000. a
Sugden, D. E., Hein, A. S., Woodward, J., Marrero, S. M., Ángel Rodés, Dunning, S. A., Stuart, F. M., Freeman, S. P., Winter, K., and Westoby, M. J.: The million-year evolution of the glacial trimline in the southernmost Ellsworth Mountains, Antarctica, Earth Planet. Sci. Lett., 469, 42–52, https://doi.org/10.1016/j.epsl.2017.04.006, 2017. a, b
Uribe, J., Zamora, R., Pulgar, S., Oberreuter, J., and Rivera, A.: Overview of the low-frequency ice penetrating radar system survey conducted to Subglacial Lake CECs, West Antarctica, available at: https://www.igsoc.org/symposia/2019/stanford/proceedings/procsfiles/procabstracts_75.html#A2948 (last access: 12 November 2020), 2019. a
Vaughan, D. G., Corr, H. F. J., Ferraccioli, F., Frearson, N., O'Hare, A., Mach, D., Holt, J. W., Blankenship, D. D., Morse, D. L., and Young, D. A.: New boundary conditions for the West Antarctic ice sheet: Subglacial topography beneath Pine Island Glacier, Geophys. Res. Lett., 33, 1–4, https://doi.org/10.1029/2005GL025588, 2006. a, b, c, d, e, f, g
Winebrenner, D. P., Smith, B. E., Catania, G. A., Conway, H. B., and Raymond, C. F.: Radio-frequency attenuation beneath Siple Dome, West Antarctica, from wide-angle and profiling radar observations, Ann. Glaciol., 37, 226–232, 2003. a
Winsborrow, M. C., Clark, C. D., and Stokes, C. R.: What controls the location of ice streams?, Earth-Sci. Rev., 103, 45–59, 2010. a
Winter, K., Woodward, J., Ross, N., Dunning, S. A., Bingham, R. G., Corr, H. F., and Siegert, M. J.: Airborne radar evidence for tributary flow switching in Institute Ice Stream, West Antarctica: Implications for ice sheet configuration and dynamics, J. Geophys. Res.-Earth, 120, 1611–1625, 2015. a
Woodward, J., Smith, A. M., Ross, N., Thoma, M., Corr, H. F. J., King, E. C., King, M. A., Grosfeld, K., Tranter, M., and Siegert, M. J.: Location for direct access to subglacial Lake Ellsworth: An assessment of geophysical data and modeling, Geophys. Res. Lett., 37, 1–5, https://doi.org/10.1029/2010GL042884, 2010. a
Zamora, R., Uribe, J., Pulgar, S., Oberreuter, J., and Rivera, A.: Ground penetrating radar system for measuring deep ice in Antarctica using software-defined radio approach, available at: https://www.igsoc.org/symposia/2019/stanford/proceedings/procsfiles/procabstracts_75.html#A2968 (last access: 12 November 2020), 2019. a
Subglacial water is important for ice sheet dynamics and stability. Despite this, there is a lack of detailed subglacial-water characterisation in West Antarctica (WA). We report 33 new subglacial lakes. Additionally, a new digital elevation model of basal topography was built and used to simulate the subglacial hydrological network in WA. The simulated subglacial hydrological catchments of Pine Island and Thwaites glaciers do not match precisely with their ice surface catchments.
Subglacial water is important for ice sheet dynamics and stability. Despite this, there is a...