Articles | Volume 15, issue 8
https://doi.org/10.5194/tc-15-4117-2021
© Author(s) 2021. 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-15-4117-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Rapid and accurate polarimetric radar measurements of ice crystal fabric orientation at the Western Antarctic Ice Sheet (WAIS) Divide ice core site
Scott Polar Research Institute, University of Cambridge, Cambridge CB2 1ER, UK
Carlos Martín
British Antarctic Survey, Natural Environment Research Council, Cambridge CB3 0ET, UK
Poul Christoffersen
Scott Polar Research Institute, University of Cambridge, Cambridge CB2 1ER, UK
Dustin M. Schroeder
Department of Geophysics, Stanford University, Stanford, CA 94305, USA
Department of Electrical Engineering, Stanford University, Stanford, CA 94305, USA
Slawek M. Tulaczyk
Department of Earth and Planetary Sciences, University of California, Santa Cruz, CA 95064, USA
Eliza J. Dawson
Department of Geophysics, Stanford University, Stanford, CA 94305, USA
Related authors
No articles found.
Amy Constance Faith King, Thomas Keith Bauska, Amaelle Landais, Carlos Martin, and Eric William Wolff
EGUsphere, https://doi.org/10.5194/egusphere-2025-3305, https://doi.org/10.5194/egusphere-2025-3305, 2025
This preprint is open for discussion and under review for Climate of the Past (CP).
Short summary
Short summary
We show how measurements of nitrogen isotopes in Antarctic ice core records can be used to show dramatic thinning of an ice sheet during ice mass changes in the Holocene. Combining such measurements with proxies for ice sheet elevation could be a powerful tool for constraining the history of ice dynamics at sites which are sensitive to rapid changes, and could contribute to constraining ice sheet models.
Ole Zeising, Álvaro Arenas-Pingarrón, Alex M. Brisbourne, and Carlos Martín
The Cryosphere, 19, 2355–2363, https://doi.org/10.5194/tc-19-2355-2025, https://doi.org/10.5194/tc-19-2355-2025, 2025
Short summary
Short summary
Ice crystal orientation influences how glacier ice deforms. Radar polarimetry is commonly used to study the bulk ice crystal orientation, but the often used coherence method only provides information of the shallow ice in fast-flowing areas. This study shows that reducing the bandwidth of high-bandwidth radar data significantly enhances the depth limit of the coherence method. This improvement helps us to better understand ice dynamics in fast-flowing ice streams.
Gavin Piccione, Terrence Blackburn, Paul Northrup, Slawek Tulaczyk, and Troy Rasbury
The Cryosphere, 19, 2247–2261, https://doi.org/10.5194/tc-19-2247-2025, https://doi.org/10.5194/tc-19-2247-2025, 2025
Short summary
Short summary
Growth of microorganisms in the Southern Ocean is limited by low iron levels. Iron delivered from beneath the Antarctic Ice Sheet is one agent that fertilizes these ecosystems, but it is unclear how this nutrient source changes through time. Here, we measured the age and chemistry of a rock that records the iron concentration of Antarctic basal water. We show that increased dissolution of iron from rocks below the ice sheet can substantially enhance iron discharge during cold climate periods.
Vikram Goel, Carlos Martin, Kenichi Matsuoka, Bhanu Pratap, Geir Moholdt, Rahul Dey, Chavarukonam M. Laluraj, and Meloth Thamban
EGUsphere, https://doi.org/10.5194/egusphere-2025-2037, https://doi.org/10.5194/egusphere-2025-2037, 2025
This preprint is open for discussion and under review for The Cryosphere (TC).
Short summary
Short summary
We identified an ideal site in coastal East Antarctica for extracting ice core that contain detailed climate records dating back 20,000 years. We surveyed two ice rises combining radar measurements with ice flow modeling to assess their suitability. One site emerged as optimal, offering well-preserved climate history with high temporal resolution. An ice core record from this site could help us understand historical interactions between sea ice, winds, and precipitation patterns in the region.
Álvaro Arenas-Pingarrón, Alex M. Brisbourne, Carlos Martín, Hugh F. J. Corr, Carl Robinson, Tom A. Jordan, and Paul V. Brennan
EGUsphere, https://doi.org/10.5194/egusphere-2025-1068, https://doi.org/10.5194/egusphere-2025-1068, 2025
Short summary
Short summary
Synthetic Aperture Radar (SAR) imaging is essential for deep englacial observations. Each pixel is formed by averaging the radar echoes within an antenna beamwidth, but the echo diversity is lost after the average. We improve the SAR interpretation if three sub-images are formed with different sub-beamwidths: each is coloured in red, green, or blue, and they are overlapped, creating a coloured image. Interpreters will better identify the slopes of internal layers, crevasses, and layer roughness.
Frédéric Parrenin, Ailsa Chung, and Carlos Martín
EGUsphere, https://doi.org/10.5194/egusphere-2024-3411, https://doi.org/10.5194/egusphere-2024-3411, 2025
Short summary
Short summary
We developed a new numerical age solver for a pseudo-steady flow tube of an ice sheet. Thanks to a new coordinate system which tracks the trajectories and a change of the time variable, our scheme combines the advantages of Eulerian and Lagrangian schemes: no numerical diffusion and no dilution of tracers. Our model is so fast that it is easy to optimize its parameters. Our model is made available to the ice sheet community as an easy to use open-source software coded in python.
Yu Wang, Chen Zhao, Rupert Gladstone, Thomas Zwinger, Benjamin K. Galton-Fenzi, and Poul Christoffersen
The Cryosphere, 18, 5117–5137, https://doi.org/10.5194/tc-18-5117-2024, https://doi.org/10.5194/tc-18-5117-2024, 2024
Short summary
Short summary
Our research delves into the future evolution of Antarctica's Wilkes Subglacial Basin (WSB) and its potential contribution to sea level rise, focusing on how basal melt is implemented at the grounding line in ice flow models. Our findings suggest that these implementation methods can significantly impact the magnitude of future ice loss projections. Under a high-emission scenario, the WSB ice sheet could undergo massive and rapid retreat between 2200 and 2300.
Robert G. Bingham, Julien A. Bodart, Marie G. P. Cavitte, Ailsa Chung, Rebecca J. Sanderson, Johannes C. R. Sutter, Olaf Eisen, Nanna B. Karlsson, Joseph A. MacGregor, Neil Ross, Duncan A. Young, David W. Ashmore, Andreas Born, Winnie Chu, Xiangbin Cui, Reinhard Drews, Steven Franke, Vikram Goel, John W. Goodge, A. Clara J. Henry, Antoine Hermant, Benjamin H. Hills, Nicholas Holschuh, Michelle R. Koutnik, Gwendolyn J.-M. C. Leysinger Vieli, Emma J. Mackie, Elisa Mantelli, Carlos Martín, Felix S. L. Ng, Falk M. Oraschewski, Felipe Napoleoni, Frédéric Parrenin, Sergey V. Popov, Therese Rieckh, Rebecca Schlegel, Dustin M. Schroeder, Martin J. Siegert, Xueyuan Tang, Thomas O. Teisberg, Kate Winter, Shuai Yan, Harry Davis, Christine F. Dow, Tyler J. Fudge, Tom A. Jordan, Bernd Kulessa, Kenichi Matsuoka, Clara J. Nyqvist, Maryam Rahnemoonfar, Matthew R. Siegfried, Shivangini Singh, Verjan Višnjević, Rodrigo Zamora, and Alexandra Zuhr
EGUsphere, https://doi.org/10.5194/egusphere-2024-2593, https://doi.org/10.5194/egusphere-2024-2593, 2024
Short summary
Short summary
The ice sheets covering Antarctica have built up over millenia through successive snowfall events which become buried and preserved as internal surfaces of equal age detectable with ice-penetrating radar. This paper describes an international initiative to work together on this archival data to build a comprehensive 3-D picture of how old the ice is everywhere across Antarctica, and how this will be used to reconstruct past and predict future ice and climate behaviour.
Nanna B. Karlsson, Dustin M. Schroeder, Louise Sandberg Sørensen, Winnie Chu, Jørgen Dall, Natalia H. Andersen, Reese Dobson, Emma J. Mackie, Simon J. Köhn, Jillian E. Steinmetz, Angelo S. Tarzona, Thomas O. Teisberg, and Niels Skou
Earth Syst. Sci. Data, 16, 3333–3344, https://doi.org/10.5194/essd-16-3333-2024, https://doi.org/10.5194/essd-16-3333-2024, 2024
Short summary
Short summary
In the 1970s, more than 177 000 km of observations were acquired from airborne radar over the Greenland ice sheet. The radar data contain information on not only the thickness of the ice, but also the properties of the ice itself. This information was recorded on film rolls and subsequently stored. In this study, we document the digitization of these film rolls that shed new and unprecedented detailed light on the Greenland ice sheet 50 years ago.
Ricardo Garza-Girón and Slawek M. Tulaczyk
The Cryosphere, 18, 1207–1213, https://doi.org/10.5194/tc-18-1207-2024, https://doi.org/10.5194/tc-18-1207-2024, 2024
Short summary
Short summary
By analyzing temperature time series over more than 20 years, we have found a discrepancy between the 2 m temperature values reported by the ERA5 reanalysis and the automatic weather stations in the McMurdo Dry Valleys, Antarctica.
Anja Løkkegaard, Kenneth D. Mankoff, Christian Zdanowicz, Gary D. Clow, Martin P. Lüthi, Samuel H. Doyle, Henrik H. Thomsen, David Fisher, Joel Harper, Andy Aschwanden, Bo M. Vinther, Dorthe Dahl-Jensen, Harry Zekollari, Toby Meierbachtol, Ian McDowell, Neil Humphrey, Anne Solgaard, Nanna B. Karlsson, Shfaqat A. Khan, Benjamin Hills, Robert Law, Bryn Hubbard, Poul Christoffersen, Mylène Jacquemart, Julien Seguinot, Robert S. Fausto, and William T. Colgan
The Cryosphere, 17, 3829–3845, https://doi.org/10.5194/tc-17-3829-2023, https://doi.org/10.5194/tc-17-3829-2023, 2023
Short summary
Short summary
This study presents a database compiling 95 ice temperature profiles from the Greenland ice sheet and peripheral ice caps. Ice viscosity and hence ice flow are highly sensitive to ice temperature. To highlight the value of the database in evaluating ice flow simulations, profiles from the Greenland ice sheet are compared to a modeled temperature field. Reoccurring discrepancies between modeled and observed temperatures provide insight on the difficulties faced when simulating ice temperatures.
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
Short summary
Short summary
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.
Isobel Rowell, Carlos Martin, Robert Mulvaney, Helena Pryer, Dieter Tetzner, Emily Doyle, Hara Madhav Talasila, Jilu Li, and Eric Wolff
Clim. Past, 19, 1699–1714, https://doi.org/10.5194/cp-19-1699-2023, https://doi.org/10.5194/cp-19-1699-2023, 2023
Short summary
Short summary
We present an age scale for a new type of ice core from a vulnerable region in West Antarctic, which is lacking in longer-term (greater than a few centuries) ice core records. The Sherman Island core extends to greater than 1 kyr. We provide modelling evidence for the potential of a 10 kyr long core. We show that this new type of ice core can be robustly dated and that climate records from this core will be a significant addition to existing regional climate records.
Alice C. Frémand, Peter Fretwell, Julien A. Bodart, Hamish D. Pritchard, Alan Aitken, Jonathan L. Bamber, Robin Bell, Cesidio Bianchi, Robert G. Bingham, Donald D. Blankenship, Gino Casassa, Ginny Catania, Knut Christianson, Howard Conway, Hugh F. J. Corr, Xiangbin Cui, Detlef Damaske, Volkmar Damm, Reinhard Drews, Graeme Eagles, Olaf Eisen, Hannes Eisermann, Fausto Ferraccioli, Elena Field, René Forsberg, Steven Franke, Shuji Fujita, Yonggyu Gim, Vikram Goel, Siva Prasad Gogineni, Jamin Greenbaum, Benjamin Hills, Richard C. A. Hindmarsh, Andrew O. Hoffman, Per Holmlund, Nicholas Holschuh, John W. Holt, Annika N. Horlings, Angelika Humbert, Robert W. Jacobel, Daniela Jansen, Adrian Jenkins, Wilfried Jokat, Tom Jordan, Edward King, Jack Kohler, William Krabill, Mette Kusk Gillespie, Kirsty Langley, Joohan Lee, German Leitchenkov, Carlton Leuschen, Bruce Luyendyk, Joseph MacGregor, Emma MacKie, Kenichi Matsuoka, Mathieu Morlighem, Jérémie Mouginot, Frank O. Nitsche, Yoshifumi Nogi, Ole A. Nost, John Paden, Frank Pattyn, Sergey V. Popov, Eric Rignot, David M. Rippin, Andrés Rivera, Jason Roberts, Neil Ross, Anotonia Ruppel, Dustin M. Schroeder, Martin J. Siegert, Andrew M. Smith, Daniel Steinhage, Michael Studinger, Bo Sun, Ignazio Tabacco, Kirsty Tinto, Stefano Urbini, David Vaughan, Brian C. Welch, Douglas S. Wilson, Duncan A. Young, and Achille Zirizzotti
Earth Syst. Sci. Data, 15, 2695–2710, https://doi.org/10.5194/essd-15-2695-2023, https://doi.org/10.5194/essd-15-2695-2023, 2023
Short summary
Short summary
This paper presents the release of over 60 years of ice thickness, bed elevation, and surface elevation data acquired over Antarctica by the international community. These data are a crucial component of the Antarctic Bedmap initiative which aims to produce a new map and datasets of Antarctic ice thickness and bed topography for the international glaciology and geophysical community.
Hilary A. Dugan, Peter T. Doran, Denys Grombacher, Esben Auken, Thue Bording, Nikolaj Foged, Neil Foley, Jill Mikucki, Ross A. Virginia, and Slawek Tulaczyk
The Cryosphere, 16, 4977–4983, https://doi.org/10.5194/tc-16-4977-2022, https://doi.org/10.5194/tc-16-4977-2022, 2022
Short summary
Short summary
In the McMurdo Dry Valleys of Antarctica, a deep groundwater system has been hypothesized to connect Don Juan Pond and Lake Vanda, both surface waterbodies that contain very high concentrations of salt. This is unusual, since permafrost in polar landscapes is thought to prevent subsurface hydrologic connectivity. We show results from an airborne geophysical survey that reveals widespread unfrozen brine in Wright Valley and points to the potential for deep valley-wide brine conduits.
Alexander O. Hager, Matthew J. Hoffman, Stephen F. Price, and Dustin M. Schroeder
The Cryosphere, 16, 3575–3599, https://doi.org/10.5194/tc-16-3575-2022, https://doi.org/10.5194/tc-16-3575-2022, 2022
Short summary
Short summary
The presence of water beneath glaciers is a control on glacier speed and ocean-caused melting, yet it has been unclear whether sizable volumes of water can exist beneath Antarctic glaciers or how this water may flow along the glacier bed. We use computer simulations, supported by observations, to show that enough water exists at the base of Thwaites Glacier, Antarctica, to form "rivers" beneath the glacier. These rivers likely moderate glacier speed and may influence its rate of retreat.
M. Reza Ershadi, Reinhard Drews, Carlos Martín, Olaf Eisen, Catherine Ritz, Hugh Corr, Julia Christmann, Ole Zeising, Angelika Humbert, and Robert Mulvaney
The Cryosphere, 16, 1719–1739, https://doi.org/10.5194/tc-16-1719-2022, https://doi.org/10.5194/tc-16-1719-2022, 2022
Short summary
Short summary
Radio waves transmitted through ice split up and inform us about the ice sheet interior and orientation of single ice crystals. This can be used to infer how ice flows and improve projections on how it will evolve in the future. Here we used an inverse approach and developed a new algorithm to infer ice properties from observed radar data. We applied this technique to the radar data obtained at two EPICA drilling sites, where ice cores were used to validate our results.
Julie Z. Miller, Riley Culberg, David G. Long, Christopher A. Shuman, Dustin M. Schroeder, and Mary J. Brodzik
The Cryosphere, 16, 103–125, https://doi.org/10.5194/tc-16-103-2022, https://doi.org/10.5194/tc-16-103-2022, 2022
Short summary
Short summary
We use L-band brightness temperature imagery from NASA's Soil Moisture Active Passive (SMAP) satellite to map the extent of perennial firn aquifer and ice slab areas within the Greenland Ice Sheet. As Greenland's climate continues to warm and seasonal surface melting increases in extent, intensity, and duration, quantifying the possible rapid expansion of perennial firn aquifers and ice slab areas has significant implications for understanding the stability of the Greenland Ice Sheet.
Marie G. P. Cavitte, Duncan A. Young, Robert Mulvaney, Catherine Ritz, Jamin S. Greenbaum, Gregory Ng, Scott D. Kempf, Enrica Quartini, Gail R. Muldoon, John Paden, Massimo Frezzotti, Jason L. Roberts, Carly R. Tozer, Dustin M. Schroeder, and Donald D. Blankenship
Earth Syst. Sci. Data, 13, 4759–4777, https://doi.org/10.5194/essd-13-4759-2021, https://doi.org/10.5194/essd-13-4759-2021, 2021
Short summary
Short summary
We present a data set consisting of ice-penetrating-radar internal stratigraphy: 26 internal reflecting horizons that cover the greater Dome C area, East Antarctica, the most extensive IRH data set to date in the region. This data set uses radar surveys collected over the span of 10 years, starting with an airborne international collaboration in 2008 to explore the region, up to the detailed ground-based surveys in support of the European Beyond EPICA – Oldest Ice (BE-OI) project.
Sarah U. Neuhaus, Slawek M. Tulaczyk, Nathan D. Stansell, Jason J. Coenen, Reed P. Scherer, Jill A. Mikucki, and Ross D. Powell
The Cryosphere, 15, 4655–4673, https://doi.org/10.5194/tc-15-4655-2021, https://doi.org/10.5194/tc-15-4655-2021, 2021
Short summary
Short summary
We estimate the timing of post-LGM grounding line retreat and readvance in the Ross Sea sector of Antarctica. Our analyses indicate that the grounding line retreated over our field sites within the past 5000 years (coinciding with a warming climate) and readvanced roughly 1000 years ago (coinciding with a cooling climate). Based on these results, we propose that the Siple Coast grounding line motions in the middle to late Holocene were driven by relatively modest changes in regional climate.
Krista F. Myers, Peter T. Doran, Slawek M. Tulaczyk, Neil T. Foley, Thue S. Bording, Esben Auken, Hilary A. Dugan, Jill A. Mikucki, Nikolaj Foged, Denys Grombacher, and Ross A. Virginia
The Cryosphere, 15, 3577–3593, https://doi.org/10.5194/tc-15-3577-2021, https://doi.org/10.5194/tc-15-3577-2021, 2021
Short summary
Short summary
Lake Fryxell, Antarctica, has undergone hundreds of meters of change in recent geologic history. However, there is disagreement on when lake levels were higher and by how much. This study uses resistivity data to map the subsurface conditions (frozen versus unfrozen ground) to map ancient shorelines. Our models indicate that Lake Fryxell was up to 60 m higher just 1500 to 4000 years ago. This amount of lake level change shows how sensitive these systems are to small changes in temperature.
David A. Lilien, Daniel Steinhage, Drew Taylor, Frédéric Parrenin, Catherine Ritz, Robert Mulvaney, Carlos Martín, Jie-Bang Yan, Charles O'Neill, Massimo Frezzotti, Heinrich Miller, Prasad Gogineni, Dorthe Dahl-Jensen, and Olaf Eisen
The Cryosphere, 15, 1881–1888, https://doi.org/10.5194/tc-15-1881-2021, https://doi.org/10.5194/tc-15-1881-2021, 2021
Short summary
Short summary
We collected radar data between EDC, an ice core spanning ~800 000 years, and BELDC, the site chosen for a new
oldest icecore at nearby Little Dome C. These data allow us to identify 50 % older internal horizons than previously traced in the area. We fit a model to the ages of those horizons at BELDC to determine the age of deep ice there. We find that there is likely to be 1.5 Myr old ice ~265 m above the bed, with sufficient resolution to preserve desired climatic information.
Slawek M. Tulaczyk and Neil T. Foley
The Cryosphere, 14, 4495–4506, https://doi.org/10.5194/tc-14-4495-2020, https://doi.org/10.5194/tc-14-4495-2020, 2020
Short summary
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.
Cited articles
Alley, R. B.: Fabrics in polar ice sheets: Development and prediction, Science, 240, 493–495, https://doi.org/10.1126/science.240.4851.493, 1988. a, b, c
Azuma, N.: A flow law for anisotropic ice and its application to ice sheets, Earth Planet. Sc. Lett., 128, 601–614, https://doi.org/10.1016/0012-821X(94)90173-2, 1994. a
Brennan, P. V., Nicholls, K. W., Lok, L. B., and Corr, H. F. J.: Phase-sensitive FMCW radar system for high-precision Antarctic ice shelf profile monitoring, IET Radar Sonar Nav., 8, 776–786, https://doi.org/10.1049/iet-rsn.2013.0053, 2014. a, b, c
Brisbourne, A. M., Martín, C., Smith, A. M., Baird, A. F., Kendall, J. M., and Kingslake, J.: Constraining Recent Ice Flow History at Korff Ice Rise, West Antarctica, Using Radar and Seismic Measurements of Ice Fabric, J. Geophys. Res.-Earth, 124, 175–194, https://doi.org/10.1029/2018JF004776, 2019. a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w
Burr, A., Noël, Trecourt, P., Bourcier, M., Gillet-Chaulet, F., Philip, A., and Martin, C. L.: The anisotropic contact response of viscoplastic monocrystalline ice particles, Acta Mater., 132, 576–585, https://doi.org/10.1016/j.actamat.2017.04.069, 2017. a
Calonne, N., Montagnat, M., Matzl, M., and Schneebeli, M.: The layered evolution of fabric and microstructure of snow at Point Barnola, Central East Antarctica, Earth Planet. Sc. Lett., 460, 293–301, https://doi.org/10.1016/j.epsl.2016.11.041, 2017. a
Conway, H. and Rasmussen, L. A.: Recent thinning and migration of the Western Divide, central West Antarctica, Geophys. Res. Lett., 36, 1–5, https://doi.org/10.1029/2009GL038072, 2009. a, b, c, d
Corr, H. F. J., Jenkins, A., Nicholls, K. W., and Doake, C. S. M.: Precise measurement of changes in ice-shelf thickness by phase-sensitive radar to determine basal melt rates, Geophys. Res. Lett., 29, 1–4, https://doi.org/10.1029/2001GL014618, 2002. a
Cuffey, K. and Paterson, W. S.: The Physics of Glaciers, 4th edn., Academic Press, Amsterdam, 2010. a
Dall, J.: Estimation of crystal orientation fabric from airborne polarimetric ice sounding radar data, in: 40th International Geoscience and Remote Sensing Symposium (IGARSS 2020), IEEE, Waikoloa, HI, 26 September–2 October 2020, 2975–2978, 2021. a
Davis, P. E., Jenkins, A., Nicholls, K. W., Brennan, P. V., Abrahamsen, E. P., Heywood, K. J., Dutrieux, P., Cho, K. H., and Kim, T. W.: Variability in Basal Melting Beneath Pine Island Ice Shelf on Weekly to Monthly Timescales, J. Geophys. Res.-Oceans, 123, 8655–8669, https://doi.org/10.1029/2018JC014464, 2018. a
Diez, A. and Eisen, O.: Seismic wave propagation in anisotropic ice – Part 1: Elasticity tensor and derived quantities from ice-core properties, The Cryosphere, 9, 367–384, https://doi.org/10.5194/tc-9-367-2015, 2015. a
DiPrinzio, C. L., Wilen, L. A., Alley, R. B., Fitzpatrick, J. J., Spencer, M. K., and Gow, A. J.: Fabric and texture at Siple Dome, Antarctica, J. Glaciol., 51, 281–290, https://doi.org/10.3189/172756505781829359, 2005. a
Doake, C. S., Corr, H. F., and Jenkins, A.: Polarization of radio waves transmitted through Antarctic ice shelves, Ann. Glaciol., 34, 165–170, https://doi.org/10.3189/172756402781817572, 2002. a
Durand, G., Gillet-Chaulet, F., Svensson, A., Gagliardini, O., Kipfstuhl, S., Meyssonnier, J., Parrenin, F., Duval, P., and Dahl-Jensen, D.: Change in ice rheology during climate variations – implications for ice flow modelling and dating of the EPICA Dome C core, Clim. Past, 3, 155–167, https://doi.org/10.5194/cp-3-155-2007, 2007. a
Eisen, O., Hamann, I., Kipfstuhl, S., Steinhage, D., and Wilhelms, F.: Direct evidence for continuous radar reflector originating from changes in crystal-orientation fabric, The Cryosphere, 1, 1–10, https://doi.org/10.5194/tc-1-1-2007, 2007. a
Ershadi, M. R., Drews, R., Martín, C., Eisen, O., Ritz, C., Corr, H., Christmann, J., Zeising, O., Humbert, A., and Mulvaney, R.: Polarimetric radar reveals the spatial distribution of ice fabric at domes in East Antarctica, The Cryosphere Discuss. [preprint], https://doi.org/10.5194/tc-2020-370, in review, 2021. a, b, c, d, e, f, g, h
Fitzpatrick, J. J., Voigt, D. E., Fegyveresi, J. M., Stevens, N. T., Spencer, M. K., Cole-Dai, J., Alley, R. B., Jardine, G. E., Cravens, E. D., Wilen, L. A., Fudge, T. J., and McConnell, J. R.: Physical properties of the WAIS divide ice core, J. Glaciol., 60, 1140–1154, https://doi.org/10.3189/2014JoG14J100, 2014. a, b, c, d, e, f, g, h, i, j
Fudge, T. J., Steig, E. J., Markle, B. R., Schoenemann, S. W., Ding, Q., Taylor, K. C., McConnell, J. R., Brook, E. J., Sowers, T., White, J. W., Alley, R. B., Cheng, H., Clow, G. D., Cole-Dai, J., Conway, H., Cuffey, K. M., Edwards, J. S., Lawrence Edwards, R., Edwards, R., Fegyveresi, J. M., Ferris, D., Fitzpatrick, J. J., Johnson, J., Hargreaves, G., Lee, J. E., Maselli, O. J., Mason, W., McGwire, K. C., Mitchell, L. E., Mortensen, N., Neff, P., Orsi, A. J., Popp, T. J., Schauer, A. J., Severinghaus, J. P., Sigl, M., Spencer, M. K., Vaughn, B. H., Voigt, D. E., Waddington, E. D., Wang, X., and Wong, G. J.: Onset of deglacial warming in West Antarctica driven by local orbital forcing, Nature, 500, 440–444, https://doi.org/10.1038/nature12376, 2013. a
Fujita, S., Matsuoka, T., Ishida, T., Matsuoka, K., and Mae, S.: A summary of the complex dielectric permittivity of ice in the megahertz range and its applications for radar sounding of polar ice sheets, in: Physics of Ice Core Records, edited by: Hondoh, T., Hokkaido University Press, Sapporo, Japan, 185–212, 2000. a
Fujita, S., Okuyama, J., Hori, A., and Hondoh, T.: Metamorphism of stratified firn at Dome Fuji, Antarctica: A mechanism for local insolation modulation of gas transport conditions during bubble close off, J. Geophys. Res.-Earth, 114, 1–21, https://doi.org/10.1029/2008JF001143, 2009. a
Gillet-Chaulet, F., Hindmarsh, R. C. A., Corr, H. F. J., King, E. C., and
Jenkins, A.: In-situ quantification of ice rheology and direct measurement of
the Raymond Effect at Summit, Greenland using a phase-sensitive radar,
Geophys. Res. Lett., 38, L24503, https://doi.org/10.1029/2011GL049843, 2011. a
Gregory, S. A., Albert, M. R., and Baker, I.: Impact of physical properties and accumulation rate on pore close-off in layered firn, The Cryosphere, 8, 91–105, https://doi.org/10.5194/tc-8-91-2014, 2014. a
Gusmeroli, A., Pettit, E. C., Kennedy, J. H., and Ritz, C.: The crystal fabric of ice from full-waveform borehole sonic logging, J. Geophys. Res.-Earth, 117, 1–13, https://doi.org/10.1029/2012JF002343, 2012. a
Hargreaves, N. D.: The polarization of radio signals in the radio echo
sounding of ice sheets, J. Phys. D Appl. Phys., 10, 1285–1304, https://doi.org/10.1088/0022-3727/10/9/012, 1977. a, b
Hargreaves, N. D.: The Radio-Frequency Birefringence of Polar Ice, J. Glaciol., 21, 301–313, https://doi.org/10.3189/s0022143000033499, 1978. a
Haynes, M. S., Chapin, E., and Schroeder, D. M.: Geometric power fall-off in radar sounding, IEEE T. Geosci. Remote, 56, 6571–6585, https://doi.org/10.1109/TGRS.2018.2840511, 2018. a
Horgan, H. J., Anandakrishnan, S., Alley, R. B., Burkett, P. G., and Peters, L. E.: Englacial seismic reflectivity: Imaging crystal-orientation fabric in West Antarctica, J. Glaciol., 57, 639–650, https://doi.org/10.3189/002214311797409686, 2011. a, b
Howat, I. M., Porter, C., Smith, B. E., Noh, M.-J., and Morin, P.: The Reference Elevation Model of Antarctica, The Cryosphere, 13, 665–674, https://doi.org/10.5194/tc-13-665-2019, 2019. a
IPCC: Climate Change 2013: The Physical Science Basis, 5th edn., Cambridge University Press, Cambridge, UK and New York, NY, USA, 2013. a
Jenkins, A., Corr, H. F. J., Nicholls, K. W., Stewart, C. L., and Doake, C. S. M.: Interactions between ice and ocean observed with phase-sensitive radar near an Antarctic ice-shelf grounding line, J. Glaciol., 52, 325–346, https://doi.org/10.3189/172756506781828502, 2006. a
Jordan, T. M., Schroeder, D. M., Castelletti, D., Li, J., and Dall, J.: A
Polarimetric Coherence Method to Determine Ice Crystal Orientation Fabric From
Radar Sounding: Application to the NEEM Ice Core Region, IEEE
T. Geosci. Remote, 57, 8641–8657, https://doi.org/10.1109/tgrs.2019.2921980,
2019. a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u
Jordan, T. M., Besson, D. Z., Kravchenko, I., Latif, U., Madison, B., Nokikov, A., and Shultz, A.: Modeling ice birefringence and oblique radio wave propagation for neutrino detection at the South Pole, Ann. Glaciol., 61, 84–91, https://doi.org/10.1017/aog.2020.18, 2020a. a
Jordan, T. M., Martín, C., Brisbourne, A. M., Schroeder, D. M., and Smith, A. M.: Radar characterization of ice crystal orientation fabric and anisotropic rheology within an Antarctic ice stream, Earth and Space Science Open Archive, 1–48, https://doi.org/10.1002/essoar.10504765.1, 2020b. a, b
Kendrick, A. K., Schroeder, D. M., Chu, W., Young, T. J., Christoffersen, P.,
Todd, J., Doyle, S. H., Box, J. E., Hubbard, A., Hubbard, B., Brennan, P. V.,
Nicholls, K. W., and Lok, L. B.: Surface Meltwater Impounded by Seasonal
Englacial Storage in West Greenland, Geophys. Res. Lett., 45, 10474–10481,
https://doi.org/10.1029/2018GL079787, 2018. a
Kennedy, J. H., Pettit, E. C., and Di Prinzio, C. L.: The evolution of crystal fabric in ice sheets and its link to climate history, J. Glaciol., 59, 357–373, https://doi.org/10.3189/2013JoG12J159, 2013. a, b, c
Kingslake, J., Hindmarsh, R. C. A., Aalgeirsdõttir, G., Conway, H., Corr, H. F. J., Gillet-Chaulet, F., Martín, C., King, E. C., Mulvaney, R., and Pritchard, H. D.: Full-depth englacial vertical ice sheet velocities measured using phase-sensitive radar, J. Geophys. Res.-Earth, 119, 2604–2618, https://doi.org/10.1002/2014JF003275, 2014. a
Kingslake, J., Martín, C., Arthern, R. J., Corr, H. F., and King, E. C.: Ice-flow reorganization in West Antarctica 2.5 kyr ago dated using radar-derived englacial flow velocities, Geophys. Res. Lett., 43, 9103–9112, https://doi.org/10.1002/2016GL070278, 2016. a
Kluskiewicz, D., Waddington, E. D., Anandakrishnan, S., Voigt, D. E., Matsuoka, K., and McCarthy, M. P.: Sonic methods for measuring crystal orientation fabric in ice, and results from the West Antarctic ice sheet (WAIS) Divide, J. Glaciol., 63, 603–617, https://doi.org/10.1017/jog.2017.20, 2017. a, b, c
Koutnik, M. R., Fudge, T. J., Conway, H., Waddington, E. D., Neumann, T. A., Cuffey, K. M., Buizert, C., and Taylor, K. C.: Holocene accumulation and ice flow near the West Antarctic Ice Sheet Divide ice core site, J. Geophys. Res.-Earth, 121, 907–924, https://doi.org/10.1002/2015JF003668, 2016. a, b, c
Li, J., Vélez González, J. A., Leuschen, C., Harish, A., Gogineni, P., Montagnat, M., Weikusat, I., Rodriguez-Morales, F., and Paden, J.: Multi-channel and multi-polarization radar measurements around the NEEM site, The Cryosphere, 12, 2689–2705, https://doi.org/10.5194/tc-12-2689-2018, 2018. a, b, c, d
Lindbäck, K., Moholdt, G., Nicholls, K. W., Hattermann, T., Pratap, B., Thamban, M., and Matsuoka, K.: Spatial and temporal variations in basal melting at Nivlisen ice shelf, East Antarctica, derived from phase-sensitive radars, The Cryosphere, 13, 2579–2595, https://doi.org/10.5194/tc-13-2579-2019, 2019. a
Looyenga, H.: Dielectric constants of heterogeneous mixtures, Physica, 31, 401–406, https://doi.org/10.1016/0031-8914(65)90045-5, 1965. a
Marsh, O. J., Fricker, H. A., Siegfried, M. R., and Christianson, K.: High basal melt rates initiate a channel at the grounding line of Ross Ice Shelf, Antarctica, Geophys. Res. Lett., 43, 250–255, https://doi.org/10.1002/2015GL066612, 2016. a
Matsuoka, K., Furukawa, T., Fujita, S., Maeno, H., Uratsuka, S., Naruse, R., and Watanabe, O.: Crystal orientation fabrics within the Antarctic ice sheet revealed by a multipolarization plane and dual-frequency radar survey, J. Geophys. Res., 108, 10, https://doi.org/10.1029/2003JB002425, 2003. a, b, c, d
Matsuoka, K., Wilen, L., Hurley, S. P., and Raymond, C. F.: Effects of birefringence within ice sheets on obliquely propagating radio waves, IEEE T. Geosci. Remote, 47, 1429–1443, https://doi.org/10.1109/TGRS.2008.2005201, 2009. a, b
Matsuoka, K., Power, D., Fujita, S., and Raymond, C. F.: Rapid development of anisotropic ice-crystal-alignment fabrics inferred from englacial radar polarimetry, central West Antarctica, J. Geophys. Res.-Earth, 117, 1–16, https://doi.org/10.1029/2012JF002440, 2012. a, b, c, d, e, f, g, h, i, j, k, l, m
Montagnat, M., Azuma, N., Dahl-Jensen, D., Eichler, J., Fujita, S., Gillet-Chaulet, F., Kipfstuhl, S., Samyn, D., Svensson, A., and Weikusat, I.: Fabric along the NEEM ice core, Greenland, and its comparison with GRIP and NGRIP ice cores, The Cryosphere, 8, 1129–1138, https://doi.org/10.5194/tc-8-1129-2014, 2014. a
Morlighem, M., Rignot, E., Binder, T., Blankenship, D., Drews, R., Eagles, G., Eisen, O., Ferraccioli, F., Forsberg, R., Fretwell, P., Goel, V., Greenbaum, J. S., Gudmundsson, H., Guo, J., Helm, V., Hofstede, C., Howat, I., Humbert, A., Jokat, W., Karlsson, N. B., Lee, W. S., Matsuoka, K., Millan, R., Mouginot, J., Paden, J., Pattyn, F., Roberts, J., Rosier, S., Ruppel, A., Seroussi, H., Smith, E. C., Steinhage, D., Sun, B., van den Broeke, M. R., van Ommen, T. D., van Wessem, M., and Young, D. A.: Deep glacial troughs and stabilizing ridges unveiled beneath the margins of the Antarctic ice sheet, Nat. Geosci., 13, 132–137, https://doi.org/10.1038/s41561-019-0510-8, 2020. a
Mott, H.: Remote Sensing with Polarimetric Radar, John Wiley and Sons Inc., New York, NY, USA, https://doi.org/10.1002/0470079819, 2006. a
Nakata, N., Bai, T., Zhang, Z., Karplus, M. S., Kaip, G. M., Walter, J. I., Booth, A. D., Christoffersen, P., and Tulaczyk, S. M.: Seismic anisotropy at the Western Antarctic Ice Sheet (WAIS) divide using explosive seismic sources, J. Glac., in preparation, 2021.
Nicholls, K. W., Corr, H. F. J., Stewart, C. L., Lok, L. B., Brennan, P. V., and Vaughan, D. G.: Instruments and methods: A ground-based radar for measuring vertical strain rates and time-varying basal melt rates in ice sheets and shelves, J. Glaciol., 61, 1079–1087, https://doi.org/10.3189/2015JoG15J073, 2015. a, b, c, d
Nicolas, J. P. and Bromwich, D. H.: Climate of West Antarctica and Influence of Marine Air Intrusions, J. Climate, 24, 49–67, https://doi.org/10.1175/2010JCLI3522.1, 2011. a
Paterson, W. S.: Why ice-age ice is sometimes “soft”, Cold Reg. Sci. Technol., 20, 75–98, https://doi.org/10.1016/0165-232X(91)90058-O, 1991. a
Sayers, C. M.: Elastic anisotropy of polycrystalline ice with transversely isotropic and orthotropic symmetry, Geophys. J. Int., 215, 155–164, https://doi.org/10.1093/gji/ggy274, 2018. a, b
Scott, R. C., Nicolas, J. P., Bromwich, D. H., Norris, J. R., and Lubin, D.: Meteorological Drivers and Large-Scale Climate Forcing of West Antarctic Surface Melt, J. Climate, 32, 665–684, https://doi.org/10.1175/JCLI-D-18-0233.1, 2019. a
Sigl, M., Fudge, T. J., Winstrup, M., Cole-Dai, J., Ferris, D., McConnell, J. R., Taylor, K. C., Welten, K. C., Woodruff, T. E., Adolphi, F., Bisiaux, M., Brook, E. J., Buizert, C., Caffee, M. W., Dunbar, N. W., Edwards, R., Geng, L., Iverson, N., Koffman, B., Layman, L., Maselli, O. J., McGwire, K., Muscheler, R., Nishiizumi, K., Pasteris, D. R., Rhodes, R. H., and Sowers, T. A.: The WAIS Divide deep ice core WD2014 chronology – Part 2: Annual-layer counting (0–31 ka BP), Clim. Past, 12, 769–786, https://doi.org/10.5194/cp-12-769-2016, 2016. a
Stewart, C. L., Christoffersen, P., Nicholls, K. W., Williams, M. J., and Dowdeswell, J. A.: Basal melting of Ross Ice Shelf from solar heat absorption in an ice-front polynya, Nat. Geosci., 12, 435–440, https://doi.org/10.1038/s41561-019-0356-0, 2019. a, b
Sun, S., Hattermann, T., Pattyn, F., Nicholls, K. W., Drews, R., and Berger, S.: Topographic Shelf Waves Control Seasonal Melting Near Antarctic Ice Shelf Grounding Lines, Geophys. Res. Lett., 46, 9824–9832, https://doi.org/10.1029/2019GL083881, 2019. a
Vaňková, I., Voytenko, D., Nicholls, K. W., Xie, S., Parizek, B. R., and Holland, D. M.: Vertical Structure of Diurnal Englacial Hydrology Cycle at Helheim Glacier, East Greenland, Geophys. Res. Lett., 45, 8352–8362, https://doi.org/10.1029/2018GL077869, 2018.
a
Vaňková, I., Nicholls, K. W., Corr, H. F. J., Makinson, K., and Brennan, P. V.: Observations of Tidal Melt and Vertical Strain at the Filchner-Ronne Ice Shelf, Antarctica, J. Geophys. Res.-Earth, 125, https://doi.org/10.1029/2019jf005280, 2020. a
Wang, B., Sun, B., Martin, C., Ferraccioli, F., Steinhage, D., Cui, X., and Siegert, M. J.: Summit of the East Antarctic ice sheet underlain by thick ice-crystal fabric layers linked to glacial-interglacial environmental change, Geol. Soc. Spec. Publ., 461, 131–143, https://doi.org/10.1144/SP461.1, 2018. a
Washam, P., Nicholls, K. W., Münchow, A., and Padman, L.: Summer surface melt thins Petermann Gletscher Ice Shelf by enhancing channelized basal melt, J. Glaciol., 65, 662–674, https://doi.org/10.1017/jog.2019.43, 2019. a
Wilen, L. A., Diprinzio, C. L., Alley, R. B., and Azuma, N.: Development, principles, and applications of automated ice fabric analyzers, Microsc. Res. Techniq., 62, 2–18, https://doi.org/10.1002/jemt.10380, 2003. a
Young, T. J. and Dawson, E. J.: Quad-polarimetric ApRES measurements along a 6 km-long transect at the WAIS Divide, December 2019 (Version 1.0) [Data set], NERC EDS UK Polar Data Centre, https://doi.org/10.5285/BA1CAF7A-D4E0-4671-972A-E567A25CCD2C, 2021. a
Young, T. J., Schroeder, D. M., Christoffersen, P., Lok, L. B., Nicholls, K. W., Brennan, P. V., Doyle, S. H., Hubbard, B., and Hubbard, A.: Resolving the internal and basal geometry of ice masses using imaging phase-sensitive radar, J. Glaciol., 64, 649–660, https://doi.org/10.1017/jog.2018.54, 2018. a, b, c
Young, T. J., Christoffersen, P., Doyle, S. H., Nicholls, K. W., Stewart, C. L., Hubbard, B., Hubbard, A., Lok, L. B., Brennan, P. V., Benn, D. I., Luckman, A., and Bougamont, M.: Physical Conditions of Fast Glacier Flow: 3. Seasonally-Evolving Ice Deformation on Store Glacier, West Greenland, J. Geophys. Res.-Earth, 124, 245–267, https://doi.org/10.1029/2018JF004821, 2019. a
Young, T. J., Schroeder, D. M., Jordan, T. M., Christoffersen, P., Tulaczyk, S. M., Culberg, R., and Bienert, N. L.: Inferring ice fabric from birefringence loss in airborne radargrams: Application to the eastern shear margin of Thwaites Glacier, West Antarctica, J. Geophys. Res.-Earth, 126, 1–26, https://doi.org/10.1029/2020jf006023, 2021. a
Short summary
If the molecules that make up ice are oriented in specific ways, the ice becomes softer and enhances flow. We use radar to measure the orientation of ice molecules in the top 1400 m of the Western Antarctic Ice Sheet Divide. Our results match those from an ice core extracted 10 years ago and conclude that the ice flow has not changed direction for the last 6700 years. Our methods are straightforward and accurate and can be applied in places across ice sheets unsuitable for ice coring.
If the molecules that make up ice are oriented in specific ways, the ice becomes softer and...