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1. Bedmap2: improved ice bed, surface and thickness datasets for Antarctica

Author

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.

Subjects
Digital Elevation Model, Satellite Radar, East Antarctica, West Antarctica, Sheet, Stream, Sea, Altimetry, Gravity, Bathymetry
Published
2013

2. Where to find 1.5 million yr old ice for the IPICS "Oldest-Ice" ice core

Author

Fischer, H, Severinghaus, J, Brook, E, Wolff, E, Albert, M, Alemany, O, Arthern, R, Bentley, C, Blankenship, D, Chappellaz, J, Creyts, T, Dahl-Jensen, D, Dinn, M, Frezzotti, M, Fujita, S, Gallee, H, Hindmarsh, R, Hudspeth, D, Jugie, G, Kawamura, K, Lipenkov, V, Miller, H, Mulvaney, R, Parrenin, F, Pattyn, F, Ritz, C, Schwander, J, Steinhage, D, van Ommen, T, and Wilhelms, F

Subjects
Climate Action, Physical Geography and Environmental Geoscience, Paleontology
Abstract

The recovery of a 1.5 million yr long ice core from Antarctica represents a keystone of our understanding of Quaternary climate, the progression of glaciation over this time period and the role of greenhouse gas cycles in this progression. Here we tackle the question of where such ice may still be found in the Antarctic ice sheet. We can show that such old ice is most likely to exist in the plateau area of the East Antarctic ice sheet (EAIS) without stratigraphic disturbance and should be able to be recovered after careful presite selection studies. Based on a simple ice and heat flow model and glaciological observations, we conclude that positions in the vicinity of major domes and saddle position on the East Antarctic Plateau will most likely have such old ice in store and represent the best study areas for dedicated reconnaissance studies in the near future. In contrast to previous ice core drill site selections, however, we strongly suggest significantly reduced ice thickness to avoid bottom melting. For example for the geothermal heat flux and accumulation conditions at Dome C, an ice thickness lower than but close to about 2500 m would be required to find 1.5 Myr old ice (i.e., more than 700 m less than at the current EPICA Dome C drill site). Within this constraint, the resolution of an Oldest-Ice record and the distance of such old ice to the bedrock should be maximized to avoid ice flow disturbances, for example, by finding locations with minimum geothermal heat flux. As the geothermal heat flux is largely unknown for the EAIS, this parameter has to be carefully determined beforehand. In addition, detailed bedrock topography and ice flow history has to be reconstructed for candidates of an Oldest-Ice ice coring site. Finally, we argue strongly for rapid access drilling before any full, deep ice coring activity commences to bring datable samples to the surface and to allow an age check of the oldest ice.

Published
2013

4. Medicine, time, and fiction in Rabelais

Author

Hindmarsh, R and Williams, W

Subjects
French, Literature
Abstract

In the prologue to Pantagruel, Rabelais’s narrator Alcofribas promises his readers that sufferers of toothache will find no better remedy than the book they have in their hands, once it has been infused with powder and pressed between hot linens. A reading influenced by the medical humanities might take Alcofribas’s hawking as indicative of Rabelais intentionally drawing a parallel between his professional identities of physician and writer, using his fiction as an alternative means of participating in the theoretical debates of his day or a vehicle for therapeutic laughter. This thesis, however, proposes that Rabelais’s fictions resist both an instrumentalist and biographical approach: reconsidering how medicine is represented across his works allows for reconsideration of the specific force of (his) fictional writing. It sets Rabelais’s fictions in relation to a range of early modern medical texts, written traces of Rabelais’s medical life, and critical histories of medicine. By focussing on different elements of the temporality of care and cure, it also proposes a new lens through which to understand the practice of medicine as a contingent and collaborative process, engaging not only the practitioner and the patient, but also the materials which mediate their encounter (including Alcofribas’s repurposed pages). Tracing Rabelais’s re-imagining of the stages classically involved in the medical encounter – Anamnesis, Diagnosis, Prognosis, and Cure – close readings will be supported by intertextual ‘suturing’ with classical and contemporary source texts, all in a bid to recover the specific animation (movement, energy, temporality) of Rabelais’s fictional writing, and the experimental, embodied, and interdisciplinary interpretative mode it prompts. This thesis is therefore an experiment in literary analysis, in the cultural history of medicine, and in the contemporary medical humanities: one in which Rabelais emerges as a powerful case study for reimagining the force of fiction from the early modern period to today.

Published
2023

5. Antarctic Bedmap data: Findable, Accessible, Interoperable, and Reusable (FAIR) sharing of 60 years of ice bed, surface, and thickness data

Author

Frémand, A. C., Fretwell, P., Bodart, J. A., Pritchard, H. D., Aitken, A., Bamber, J. L., Bell, R., Bianchi, C., Bingham, R. G., Blankenship, D. D., Casassa, G., Catania, G., Christianson, K., Conway, H., Corr, H. F. J., Cui, X., Damaske, D., Damm, V., Drews, R., Eagles, G., Eisen, O., Eisermann, H., Ferraccioli, F., Field, E., Forsberg, R., Franke, S., Fujita, S., Gim, Y., Goel, V., Gogineni, S. P., Greenbaum, J., Hills, B., Hindmarsh, R. C. A., Hoffman, A. O., Holmlund, P., Holschuh, N., Holt, J. W., Horlings, A. N., Humbert, A., Jacobel, R. W., Jansen, D., Jenkins, A., Jokat, W., Jordan, T., King, E., Kohler, J., Krabill, W., Kusk Gillespie, M., Langley, K., Lee, J., Leitchenkov, G., Leuschen, C., Luyendyk, B., MacGregor, J., MacKie, E., Matsuoka, K., Morlighem, M., Mouginot, J., Nitsche, F. O., Nogi, Y., Nost, O. A., Paden, J., Pattyn, F., Popov, S. V., Rignot, E., Rippin, D. M., Rivera, A., Roberts, J., Ross, N., Ruppel, A., Schroeder, D. M., Siegert, M. J., Smith, A. M., Steinhage, D., Studinger, M., Sun, B., Tabacco, I., Tinto, K., Urbini, S., Vaughan, D., Welch, B. C., Wilson, D. S., Young, D. A., Zirizzotti, A., Frémand, A. C., Fretwell, P., Bodart, J. A., Pritchard, H. D., Aitken, A., Bamber, J. L., Bell, R., Bianchi, C., Bingham, R. G., Blankenship, D. D., Casassa, G., Catania, G., Christianson, K., Conway, H., Corr, H. F. J., Cui, X., Damaske, D., Damm, V., Drews, R., Eagles, G., Eisen, O., Eisermann, H., Ferraccioli, F., Field, E., Forsberg, R., Franke, S., Fujita, S., Gim, Y., Goel, V., Gogineni, S. P., Greenbaum, J., Hills, B., Hindmarsh, R. C. A., Hoffman, A. O., Holmlund, P., Holschuh, N., Holt, J. W., Horlings, A. N., Humbert, A., Jacobel, R. W., Jansen, D., Jenkins, A., Jokat, W., Jordan, T., King, E., Kohler, J., Krabill, W., Kusk Gillespie, M., Langley, K., Lee, J., Leitchenkov, G., Leuschen, C., Luyendyk, B., MacGregor, J., MacKie, E., Matsuoka, K., Morlighem, M., Mouginot, J., Nitsche, F. O., Nogi, Y., Nost, O. A., Paden, J., Pattyn, F., Popov, S. V., Rignot, E., Rippin, D. M., Rivera, A., Roberts, J., Ross, N., Ruppel, A., Schroeder, D. M., Siegert, M. J., Smith, A. M., Steinhage, D., Studinger, M., Sun, B., Tabacco, I., Tinto, K., Urbini, S., Vaughan, D., Welch, B. C., Wilson, D. S., Young, D. A., and Zirizzotti, A.

Abstract

One of the key components of this research has been the mapping of Antarctic bed topography and ice thickness parameters that are crucial for modelling ice flow and hence for predicting future ice loss and the ensuing sea level rise. Supported by the Scientific Committee on Antarctic Research (SCAR), the Bedmap3 Action Group aims not only to produce new gridded maps of ice thickness and bed topography for the international scientific community, but also to standardize and make available all the geophysical survey data points used in producing the Bedmap gridded products. Here, we document the survey data used in the latest iteration, Bedmap3, incorporating and adding to all of the datasets previously used for Bedmap1 and Bedmap2, including ice bed, surface and thickness point data from all Antarctic geophysical campaigns since the 1950s. More specifically, we describe the processes used to standardize and make these and future surveys and gridded datasets accessible under the Findable, Accessible, Interoperable, and Reusable (FAIR) data principles. With the goals of making the gridding process reproducible and allowing scientists to re-use the data freely for their own analysis, we introduce the new SCAR Bedmap Data Portal (https://bedmap.scar.org, last access: 1 March 2023) created to provide unprecedented open access to these important datasets through a web-map interface. We believe that this data release will be a valuable asset to Antarctic research and will greatly extend the life cycle of the data held within it. Data are available from the UK Polar Data Centre: https://data.bas.ac.uk (last access: 5 May 2023​​​​​​​). See the Data availability section for the complete list of datasets.

Published
2023

6. Exploration of Ellsworth Subglacial Lake: a concept paper on the development, organisation and execution of an experiment to explore, measure and sample the environment of a West Antarctic subglacial lake : The Lake Ellsworth Consortium

Author

Siegert, M. J., Behar, A., Bentley, M., Blake, D., Bowden, S., Christoffersen, P., Cockell, C., Corr, H., Cullen, D. C., Edwards, H., Ellery, A., Ellis-Evans, C., Griffiths, G., Hindmarsh, R., Hodgson, D. A., King, E., Lamb, H., Lane, L., Makinson, K., Mowlem, M., Parnell, J., Pearce, D. A., Priscu, J., Rivera, A., Sephton, M. A., Sims, M. R., Smith, A . M., Tranter, M., Wadham, J. L., Wilson, G., Woodward, J., Amils, Ricardo, editor, Ellis-Evans, Cynan, editor, and Hinghofer-Szalkay, Helmut, editor

Published
2007
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8. Exploration of Ellsworth Subglacial Lake: a concept paper on the development, organisation and execution of an experiment to explore, measure and sample the environment of a West Antarctic subglacial lake: The Lake Ellsworth Consortium

Author

Siegert, M.J., Behar, A., Bentley, M., Blake, D., Bowden, S., Christoffersen, P., Cockell, C., Corr, H., Cullen, D. C., Edwards, H., Ellery, A., Ellis-Evans, C., Griffiths, G., Hindmarsh, R., Hodgson, D. A., King, E., Lamb, H., Lane, L., Makinson, K., Mowlem, M., Parnell, J., Pearce, D. A., Priscu, J., Rivera, A., Sephton, M. A., Sims, M. R., Smith, A . M., Tranter, M., Wadham, J. L., Wilson, G., and Woodward, J.

Published
2007
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9. Probe technology for the direct measurement and sampling of Ellsworth Subglacial Lake

Author

Mowlem, Matthew C., primary, Tsaloglou, Maria-Nefeli, additional, Waugh, Edward M., additional, Floquet, Cedric F. A., additional, Saw, Kevin, additional, Fowler, Lee, additional, Brown, Robin, additional, Pearce, David, additional, Wyatt, James B., additional, Beaton, Alexander D., additional, Brito, Mario P., additional, Hodgson, Dominic A., additional, Griffiths, Gwyn, additional, Bentley, M., additional, Blake, D., additional, Capper, L., additional, Clarke, R., additional, Cockell, C., additional, Corr, H., additional, Harris, W., additional, Hill, C., additional, Hindmarsh, R., additional, King, E., additional, Lamb, H., additional, Maher, B., additional, Makinson, K., additional, Parnell, J., additional, Priscu, J., additional, Rivera, A., additional, Ross, N., additional, Siegert, M. J., additional, Smith, A., additional, Tait, A., additional, Tranter, M., additional, Wadham, J., additional, Whalley, B., additional, and Woodward, J., additional

Published
2011
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10. Ellsworth Subglacial Lake, West Antarctica: A review of its history and recent field campaigns

Author

Ross, N., primary, Siegert, M. J., additional, Rivera, A., additional, Bentley, M. J., additional, Blake, D., additional, Capper, L., additional, Clarke, R., additional, Cockell, C. S., additional, Corr, H. F. J., additional, Harris, W., additional, Hill, C., additional, Hindmarsh, R. C. A., additional, Hodgson, D. A., additional, King, E. C., additional, Lamb, H., additional, Maher, B., additional, Makinson, K., additional, Mowlem, M., additional, Parnell, J., additional, Pearce, D. A., additional, Priscu, J., additional, Smith, A. M., additional, Tait, A., additional, Tranter, M., additional, Wadham, J. L., additional, Whalley, W. B., additional, and Woodward, J., additional

Published
2011
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11. Exploration of Ellsworth Subglacial Lake: a concept paper on the development, organisation and execution of an experiment to explore, measure and sample the environment of a West Antarctic subglacial lake

Author

Siegert, M. J., primary, Behar, A., additional, Bentley, M., additional, Blake, D., additional, Bowden, S., additional, Christoffersen, P., additional, Cockell, C., additional, Corr, H., additional, Cullen, D. C., additional, Edwards, H., additional, Ellery, A., additional, Ellis-Evans, C., additional, Griffiths, G., additional, Hindmarsh, R., additional, Hodgson, D. A., additional, King, E., additional, Lamb, H., additional, Lane, L., additional, Makinson, K., additional, Mowlem, M., additional, Parnell, J., additional, Pearce, D. A., additional, Priscu, J., additional, Rivera, A., additional, Sephton, M. A., additional, Sims, M. R., additional, Smith, A . M., additional, Tranter, M., additional, Wadham, J. L., additional, Wilson, G., additional, and Woodward, J., additional

Published
2006
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12. Modelling glacial erosional landform development

Author

Hindmarsh, R. C. A.

Subjects
551.31, Glaciology & snow & ice & permafrost
Abstract

Glacial erosional systems exhibit a complex, highly scaledependent phenomenology. Some aspects of modelling the development of glacial erosional landforms in response to glacial erosional processes acting over a wide range of scales are considered. The physics of ice at the glacier sole is discussed. A simple ice-water mixture theory is proposed. A method for finding the solution of the equations of motion of ice at the glacier sole based on the finite element velocities-pressure formulation is shown, which includes novel formulations for the sliding boundary condition, compression of ice and flow of water between ice and bedrock. These finite element formulations are used to simulate flows at the ice-rock interface. The use of the Laplace equation in simulating uni-axial flow is also considered, and further simulations are carried out using this equation. The results from these finite element simulations are used to consider erosional processes occurring at the glacier bed. The processes of abrasion are considered, and previous models are shown to be physically inconsistent. Cavitation, transiency and heterogeneity are shown to have an effect on clast-bed contact forces, and the local viscosity of ice is identified as being a further controlling variable on abrasion. These results are used to consider the likely development of hummocks of bedrock. A mass-balance analysis of basal debris is carried out and shown to have an important effect on erosional patterns. The equations describing the movement of a surface normal to itself are considered. Various solution techniques for these equations are tested, and requirements for the persistence of form under lowering are given. The modelling strategy used in this thesis is a nested hierarchy, with the various hierarchical levels corresponding to different scales. The effect of this hierarchisation on the modelling is discussed with respect to the generic properties of the systems, explanation and testability.

Published
1985

13. Getting around Antarctica: New High-Resolution Mappings of the Grounded and Freely-Floating Boundaries of the Antarctic Ice Sheet Created for the International Polar Year

Author

Bindschadler, R, Choi, H, Wichlacz, A, Bingham, R, Bohlander, J, Brunt, K, Corr, H, Drews, R, Fricker, H, Hall, M, Hindmarsh, R, Kohler, J, Padman, L, Rack, W, Rotschkly, G, Urbini, S, Vornberger, P, and Young, N

Subjects
Geosciences (General)
Abstract

Two ice-dynamic transitions of the Antarctic ice sheet - the boundary of grounded ice features and the freely-floating boundary - are mapped at 15-m resolution by participants of the International Polar Year project ASAID using customized software combining Landsat-7 imagery and ICESat/GLAS laser altimetry. The grounded ice boundary is 53 610 km long; 74% abuts to floating ice shelves or outlet glaciers, 19% is adjacent to open or sea-ice covered ocean, and 7% of the boundary ice terminates on land. The freely-floating boundary, called here the hydrostatic line, is the most landward position on ice shelves that expresses the full amplitude of oscillating ocean tides. It extends 27 521 km and is discontinuous. Positional (one-sigma) accuracies of the grounded ice boundary vary an order of magnitude ranging from +/- 52m for the land and open-ocean terminating segments to +/- 502m for the outlet glaciers. The hydrostatic line is less well positioned with errors over 2 km. Elevations along each line are selected from 6 candidate digital elevation models based on their agreement with ICESat elevation values and surface shape inferred from the Landsat imagery. Elevations along the hydrostatic line are converted to ice thicknesses by applying a firn-correction factor and a flotation criterion. BEDMAP-compiled data and other airborne data are compared to the ASAID elevations and ice thicknesses to arrive at quantitative (one-sigma) uncertainties of surface elevations of +/-3.6, +/-9.6, +/-11.4, +/-30 and +/-100m for five ASAID-assigned confidence levels. Over one-half of the surface elevations along the grounded ice boundary and over one-third of the hydrostatic line elevations are ranked in the highest two confidence categories. A comparison between ASAID-calculated ice shelf thicknesses and BEDMAP-compiled data indicate a thin-ice bias of 41.2+/-71.3m for the ASAID ice thicknesses. The relationship between the seaward offset of the hydrostatic line from the grounded ice boundary only weakly matches a prediction based on beam theory. The mapped products along with the customized software to generate them and a variety of intermediate products are available from the National Snow and Ice Data Center.

Published
2011
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14. The Ross Sea Dipole-temperature, snow accumulation and sea ice variability in the Ross Sea region, Antarctica, over the past 2700 years

Author

Bertler, N, Conway, H, Dahl-Jensen, D, Emanuelsson, D, Winstrup, M, Vallelonga, P, Lee, J, Brook, E, Severinghaus, J, Fudge, T, Keller, E, Troy Baisden, W, Hindmarsh, R, Neff, P, Blunier, T, Edwards, R, Mayewski, P, Kipfstuhl, S, Buizert, C, Canessa, S, Dadic, R, Kjær, H, Kurbatov, A, Zhang, D, Waddington, E, Baccolo, G, Beers, T, Brightley, H, Carter, L, Clemens-Sewall, D, Ciobanu, V, Delmonte, B, Eling, L, Ellis, A, Ganesh, S, Golledge, N, Haines, S, Handley, M, Hawley, R, Hogan, C, Johnson, K, Korotkikh, E, Lowry, D, Mandeno, D, Mckay, R, Menking, J, Naish, T, Noerling, C, Ollive, A, Orsi, A, Proemse, B, Pyne, A, Pyne, R, Renwick, J, Scherer, R, Semper, S, Simonsen, M, Sneed, S, Steig, E, Tuohy, A, Ulayottil Venugopal, A, Valero-Delgado, F, Venkatesh, J, Wang, F, Wang, S, Winski, D, Holly, W, Whiteford, A, Xiao, C, Yang, J, Zhang, X, Bertler, Nancy A. N., Conway, Howard, Dahl-Jensen, Dorthe, Emanuelsson, Daniel B., Winstrup, Mai, Vallelonga, Paul T., Lee, James E., Brook, Ed J., Severinghaus, Jeffrey P., Fudge, Taylor J., Keller, Elizabeth D., Troy Baisden, W., Hindmarsh, Richard C. A., Neff, Peter D., Blunier, Thomas, Edwards, Ross, Mayewski, Paul A., Kipfstuhl, Sepp, Buizert, Christo, Canessa, Silvia, Dadic, Ruzica, Kjær, Helle A., Kurbatov, Andrei, Zhang, Dongqi, Waddington, Edwin D., Baccolo, Giovanni, Beers, Thomas, Brightley, Hannah J., Carter, Lionel, Clemens-Sewall, David, Ciobanu, Viorela G., Delmonte, Barbara, Eling, Lukas, Ellis, Aja, Ganesh, Shruthi, Golledge, Nicholas R., Haines, Skylar, Handley, Michael, Hawley, Robert L., Hogan, Chad M., Johnson, Katelyn M., Korotkikh, Elena, Lowry, Daniel P., Mandeno, Darcy, McKay, Robert M., Menking, James A., Naish, Timothy R., Noerling, Caroline, Ollive, Agathe, Orsi, Anaïs, Proemse, Bernadette C., Pyne, Alexander R., Pyne, Rebecca L., Renwick, James, Scherer, Reed P., Semper, Stefanie, Simonsen, Marius, Sneed, Sharon B., Steig, Eric J., Tuohy, Andrea, Ulayottil Venugopal, Abhijith, Valero-Delgado, Fernando, Venkatesh, Janani, Wang, Feitang, Wang, Shimeng, Winski, Dominic A., Holly, Winton, Whiteford, Arran, Xiao, Cunde, Yang, Jiao, Zhang, Xin, Bertler, N, Conway, H, Dahl-Jensen, D, Emanuelsson, D, Winstrup, M, Vallelonga, P, Lee, J, Brook, E, Severinghaus, J, Fudge, T, Keller, E, Troy Baisden, W, Hindmarsh, R, Neff, P, Blunier, T, Edwards, R, Mayewski, P, Kipfstuhl, S, Buizert, C, Canessa, S, Dadic, R, Kjær, H, Kurbatov, A, Zhang, D, Waddington, E, Baccolo, G, Beers, T, Brightley, H, Carter, L, Clemens-Sewall, D, Ciobanu, V, Delmonte, B, Eling, L, Ellis, A, Ganesh, S, Golledge, N, Haines, S, Handley, M, Hawley, R, Hogan, C, Johnson, K, Korotkikh, E, Lowry, D, Mandeno, D, Mckay, R, Menking, J, Naish, T, Noerling, C, Ollive, A, Orsi, A, Proemse, B, Pyne, A, Pyne, R, Renwick, J, Scherer, R, Semper, S, Simonsen, M, Sneed, S, Steig, E, Tuohy, A, Ulayottil Venugopal, A, Valero-Delgado, F, Venkatesh, J, Wang, F, Wang, S, Winski, D, Holly, W, Whiteford, A, Xiao, C, Yang, J, Zhang, X, Bertler, Nancy A. N., Conway, Howard, Dahl-Jensen, Dorthe, Emanuelsson, Daniel B., Winstrup, Mai, Vallelonga, Paul T., Lee, James E., Brook, Ed J., Severinghaus, Jeffrey P., Fudge, Taylor J., Keller, Elizabeth D., Troy Baisden, W., Hindmarsh, Richard C. A., Neff, Peter D., Blunier, Thomas, Edwards, Ross, Mayewski, Paul A., Kipfstuhl, Sepp, Buizert, Christo, Canessa, Silvia, Dadic, Ruzica, Kjær, Helle A., Kurbatov, Andrei, Zhang, Dongqi, Waddington, Edwin D., Baccolo, Giovanni, Beers, Thomas, Brightley, Hannah J., Carter, Lionel, Clemens-Sewall, David, Ciobanu, Viorela G., Delmonte, Barbara, Eling, Lukas, Ellis, Aja, Ganesh, Shruthi, Golledge, Nicholas R., Haines, Skylar, Handley, Michael, Hawley, Robert L., Hogan, Chad M., Johnson, Katelyn M., Korotkikh, Elena, Lowry, Daniel P., Mandeno, Darcy, McKay, Robert M., Menking, James A., Naish, Timothy R., Noerling, Caroline, Ollive, Agathe, Orsi, Anaïs, Proemse, Bernadette C., Pyne, Alexander R., Pyne, Rebecca L., Renwick, James, Scherer, Reed P., Semper, Stefanie, Simonsen, Marius, Sneed, Sharon B., Steig, Eric J., Tuohy, Andrea, Ulayottil Venugopal, Abhijith, Valero-Delgado, Fernando, Venkatesh, Janani, Wang, Feitang, Wang, Shimeng, Winski, Dominic A., Holly, Winton, Whiteford, Arran, Xiao, Cunde, Yang, Jiao, and Zhang, Xin

Abstract

High-resolution, well-dated climate archives provide an opportunity to investigate the dynamic interactions of climate patterns relevant for future projections. Here, we present data from a new, annually dated ice core record from the eastern Ross Sea, named the Roosevelt Island Climate Evolution (RICE) ice core. Comparison of this record with climate reanalysis data for the 1979-2012 interval shows that RICE reliably captures temperature and snow precipitation variability in the region. Trends over the past 2700 years in RICE are shown to be distinct from those in West Antarctica and the western Ross Sea captured by other ice cores. For most of this interval, the eastern Ross Sea was warming (or showing isotopic enrichment for other reasons), with increased snow accumulation and perhaps decreased sea ice concentration. However, West Antarctica cooled and the western Ross Sea showed no significant isotope temperature trend. This pattern here is referred to as the Ross Sea Dipole. Notably, during the Little Ice Age, West Antarctica and the western Ross Sea experienced colder than average temperatures, while the eastern Ross Sea underwent a period of warming or increased isotopic enrichment. From the 17th century onwards, this dipole relationship changed. All three regions show current warming, with snow accumulation declining in West Antarctica and the eastern Ross Sea but increasing in the western Ross Sea. We interpret this pattern as reflecting an increase in sea ice in the eastern Ross Sea with perhaps the establishment of a modern Roosevelt Island polynya as a local moisture source for RICE

Published
2018

15. Basal freeze-on generates complex ice-sheet stratigraphy

Author

Leysinger Vieli, G J-M C; https://orcid.org/0000-0003-1817-0641, Martin, C, Hindmarsh, R C A; https://orcid.org/0000-0003-1633-2416, Lüthi, Martin P; https://orcid.org/0000-0003-4419-8496, Leysinger Vieli, G J-M C; https://orcid.org/0000-0003-1817-0641, Martin, C, Hindmarsh, R C A; https://orcid.org/0000-0003-1633-2416, and Lüthi, Martin P; https://orcid.org/0000-0003-4419-8496

Abstract

Large, plume-like internal ice-layer-structures have been observed in radar images from both Antarctica and Greenland, rising from the ice-sheet base to up to half of the ice thickness. Their origins are not yet understood. Here, we simulate their genesis by basal freeze-on using numerical ice-flow modelling and analyse the transient evolution of the emerging ice-plume and the surrounding ice-layer structure as a function of both freeze-on rate and ice flux. We find good agreement between radar observations, modelled ice-plume geometry and internal layer structure, and further show that plume height relates primarily to ice-flux and only secondarily to freeze-on. An in-depth analysis, performed for Northern Greenland of observed spatial plume distribution related to ice flow, basal topography and water availability supports our findings regarding ice flux and suggests freeze-on is controlled by ascending subglacial water flow. Our results imply that widespread basal freeze-on strongly affects ice stratigraphy and consequently ice-core interpretations.

Published
2018

16. The Ross Sea Dipole-temperature, snow accumulation and sea ice variability in the Ross Sea region, Antarctica, over the past 2700 years

Author

Bertler, N., Conway, H., Dahl-Jensen, D., Emanuelsson, D., Winstrup, M., Vallelonga, P., Lee, J., Brook, E., Severinghaus, J., Fudge, T., Keller, E., Troy Baisden, W., Hindmarsh, R., Neff, P., Blunier, T., Edwards, Peter, Mayewski, P., Kipfstuhl, S., Buizert, C., Canessa, S., Dadic, R., Kjær, H., Kurbatov, A., Zhang, D., Waddington, E., Baccolo, G., Beers, T., Brightley, H., Carter, L., Clemens-Sewall, D., Ciobanu, V., Delmonte, B., Eling, L., Ellis, A., Ganesh, S., Golledge, N., Haines, S., Handley, M., Hawley, R., Hogan, C., Johnson, K., Korotkikh, E., Lowry, D., Mandeno, D., McKay, R., Menking, J., Naish, T., Noerling, C., Ollive, A., Orsi, A., Proemse, B., Pyne, A., Pyne, R., Renwick, J., Scherer, R., Semper, S., Simonsen, M., Sneed, S., Steig, E., Tuohy, A., Ulayottil Venugopal, A., Valero-Delgado, F., Venkatesh, J., Wang, F., Wang, S., Winski, D., Holly, W., Whiteford, A., Xiao, C., Yang, J., Zhang, X., Bertler, N., Conway, H., Dahl-Jensen, D., Emanuelsson, D., Winstrup, M., Vallelonga, P., Lee, J., Brook, E., Severinghaus, J., Fudge, T., Keller, E., Troy Baisden, W., Hindmarsh, R., Neff, P., Blunier, T., Edwards, Peter, Mayewski, P., Kipfstuhl, S., Buizert, C., Canessa, S., Dadic, R., Kjær, H., Kurbatov, A., Zhang, D., Waddington, E., Baccolo, G., Beers, T., Brightley, H., Carter, L., Clemens-Sewall, D., Ciobanu, V., Delmonte, B., Eling, L., Ellis, A., Ganesh, S., Golledge, N., Haines, S., Handley, M., Hawley, R., Hogan, C., Johnson, K., Korotkikh, E., Lowry, D., Mandeno, D., McKay, R., Menking, J., Naish, T., Noerling, C., Ollive, A., Orsi, A., Proemse, B., Pyne, A., Pyne, R., Renwick, J., Scherer, R., Semper, S., Simonsen, M., Sneed, S., Steig, E., Tuohy, A., Ulayottil Venugopal, A., Valero-Delgado, F., Venkatesh, J., Wang, F., Wang, S., Winski, D., Holly, W., Whiteford, A., Xiao, C., Yang, J., and Zhang, X.

Abstract

High-resolution, well-dated climate archives provide an opportunity to investigate the dynamic interactions of climate patterns relevant for future projections. Here, we present data from a new, annually dated ice core record from the eastern Ross Sea, named the Roosevelt Island Climate Evolution (RICE) ice core. Comparison of this record with climate reanalysis data for the 1979-2012 interval shows that RICE reliably captures temperature and snow precipitation variability in the region. Trends over the past 2700 years in RICE are shown to be distinct from those in West Antarctica and the western Ross Sea captured by other ice cores. For most of this interval, the eastern Ross Sea was warming (or showing isotopic enrichment for other reasons), with increased snow accumulation and perhaps decreased sea ice concentration. However, West Antarctica cooled and the western Ross Sea showed no significant isotope temperature trend. This pattern here is referred to as the Ross Sea Dipole. Notably, during the Little Ice Age, West Antarctica and the western Ross Sea experienced colder than average temperatures, while the eastern Ross Sea underwent a period of warming or increased isotopic enrichment. From the 17th century onwards, this dipole relationship changed. All three regions show current warming, with snow accumulation declining in West Antarctica and the eastern Ross Sea but increasing in the western Ross Sea. We interpret this pattern as reflecting an increase in sea ice in the eastern Ross Sea with perhaps the establishment of a modern Roosevelt Island polynya as a local moisture source for RICE.

Published
2018

17. Where to find 1.5 million yr old ice for the IPICS 'Oldest-Ice' ice core

Author

Fischer, H., Severinghaus, J., Brook, E., Wolff, E., Albert, M., Alemany, O., Arthern, R., Bentley, C., Blankenship, D., Chappellaz, J., Creyts, T., Dahl-Jensen, D., Dinn, M., Frezzotti, M., Fujita, S., Gallee, H., Hindmarsh, R., Hudspeth, D., Jugie, G., Kawamura, K., Lipenkov, V., Miller, H., Mulvaney, R., Parrenin, Frédéric, Pattyn, F., Ritz, C., Schwander, J., Steinhage, D., Van Ommen, T., Wilhelms, F., Fischer, H., Severinghaus, J., Brook, E., Wolff, E., Albert, M., Alemany, O., Arthern, R., Bentley, C., Blankenship, D., Chappellaz, J., Creyts, T., Dahl-Jensen, D., Dinn, M., Frezzotti, M., Fujita, S., Gallee, H., Hindmarsh, R., Hudspeth, D., Jugie, G., Kawamura, K., Lipenkov, V., Miller, H., Mulvaney, R., Parrenin, F., Pattyn, F., Ritz, C., Schwander, J., Steinhage, D., Van Ommen, T., Wilhelms, F., Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, Scripps Institution of Oceanography (SIO), University of California [San Diego] (UC San Diego), University of California-University of California, British Antarctic Survey (BAS), Natural Environment Research Council (NERC), Département de Physique Théorique, University of Geneva [Switzerland], CLIPS, Laboratoire de glaciologie et géophysique de l'environnement (LGGE), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS), Centre for Ice and Climate [Copenhagen], Niels Bohr Institute [Copenhagen] (NBI), Faculty of Science [Copenhagen], University of Copenhagen = Københavns Universitet (KU)-University of Copenhagen = Københavns Universitet (KU)-Faculty of Science [Copenhagen], University of Copenhagen = Københavns Universitet (KU)-University of Copenhagen = Københavns Universitet (KU), Italian National agency for new technologies, Energy and sustainable economic development [Frascati] (ENEA), National Institute of Polar Research [Tokyo] (NiPR), Physical Science Division, Natural Environment Research Council (NERC)-Natural Environment Research Council (NERC), Arctic and Antarctic Research Institute (AARI), Russian Federal Service for Hydrometeorology and Environmental Monitoring (Roshydromet), Institut des Géosciences de l’Environnement (IGE), Institut de Recherche pour le Développement (IRD)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Université Libre de Bruxelles [Bruxelles] (ULB), Physics Institute, University of Berne, Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung (AWI), Antarctic Climate and Ecosystems Cooperative Research Centre (ACE-CRC), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut de Recherche pour le Développement (IRD)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Université libre de Bruxelles (ULB), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Scripps Institution of Oceanography (SIO - UC San Diego), University of California (UC)-University of California (UC), Université de Genève = University of Geneva (UNIGE), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), University of Copenhagen = Københavns Universitet (UCPH)-University of Copenhagen = Københavns Universitet (UCPH)-Faculty of Science [Copenhagen], University of Copenhagen = Københavns Universitet (UCPH)-University of Copenhagen = Københavns Universitet (UCPH), Institut de Recherche pour le Développement (IRD)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), and Universität Bern [Bern] (UNIBE)

Subjects
Paléontologie et paléoécologie, Antarctic Plateau, sub-01, lcsh:Environmental protection, glaciation, heat flux, Stratigraphie, ice flow, Physical Geography and Environmental Geoscience, Quaternary, Environnement et pollution, lcsh:Environmental pollution, Dome Concordia, paleoclimate, lcsh:TD169-171.8, [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology, lcsh:Environmental sciences, ComputingMilieux_MISCELLANEOUS, lcsh:GE1-350, Paleontology, Calluna vulgaris, East Antarctica, cryosphere, Climate Action, greenhouse gas, [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology, geothermal energy, lcsh:TD172-193.5, Antarctica, bedrock, ice core, ice thickness
Abstract

The recovery of a 1.5 million yr long ice core from Antarctica represents a keystone of our understanding of Quaternary climate, the progression of glaciation over this time period and the role of greenhouse gas cycles in this progression. Here we tackle the question of where such ice may still be found in the Antarctic ice sheet. We can show that such old ice is most likely to exist in the plateau area of the East Antarctic ice sheet (EAIS) without stratigraphic disturbance and should be able to be recovered after careful presite selection studies. Based on a simple ice and heat flow model and glaciological observations, we conclude that positions in the vicinity of major domes and saddle position on the East Antarctic Plateau will most likely have such old ice in store and represent the best study areas for dedicated reconnaissance studies in the near future. In contrast to previous ice core drill site selections, however, we strongly suggest significantly reduced ice thickness to avoid bottom melting. For example for the geothermal heat flux and accumulation conditions at Dome C, an ice thickness lower than but close to about 2500 m would be required to find 1.5 Myr old ice (i.e. more than 700 m less than at the current EPICA Dome C drill site). Within this constraint, the resolution of an Oldest-Ice record and the distance of such old ice to the bedrock should be maximized to avoid ice flow disturbances, for example, by finding locations with minimum geothermal heat flux. As the geothermal heat flux is largely unknown for the EAIS, this parameter has to be carefully determined beforehand. In addition, detailed bedrock topography and ice flow history has to be reconstructed for candidates of an Oldest-Ice ice coring site. Finally, we argue strongly for rapid access drilling before any full, deep ice coring activity commences to bring datable samples to the surface and to allow an age check of the oldest ice., SCOPUS: ar.j, info:eu-repo/semantics/published

Published
2013
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18. Time-dependence of the spatial pattern of accumulation rate in East Antarctica deduced from isochronic radar layers using a 3-D numerical ice flow model

Author

Leysinger Vieli, G. J.-M. C., Hindmarsh, R. C. A., Siegert, M. J., and Bo, S.

Subjects
Atmospheric Science, Radar layers, Geophysics, Accumulation, Space and Planetary Science, Isochrones, Earth and Planetary Sciences (miscellaneous), East Antarctica, Numerical modelling
Abstract

In East Antarctica surface mass balance data can only be obtained from the sparsely distributed ice cores when considering time periods greater than a few decades. Observations of internal layers measured by airborne ice penetrating radar, in principle, permit extrapolation of mass balance information from these ice cores. We use radar survey lines gathered in the 1970s, and a three-dimensional numerical model, to investigate the feasibility of such extrapolation, seeking to match the calculations of englacial layer geometry with observations. First, we justify the use of a three-dimensional model by showing that simple vertical flow models cannot explain all the observations and that horizontal advection is a significant glacial process. Then we examine processes that affect calculations of layer geometry, finding that spatial accumulation-rate patterns are extremely important while geothermal heat flux and flow mode (sliding or internal deformation) are of substantially less importance. Where the layer is from the Last Glacial Maximum (17.5 ka), we find a very good match between the spatial pattern of accumulation rates inferred from this layer and the modern spatial pattern of accumulation rates. When considering deeper layers from beyond the current interglacial, we find that a different spatial accumulation-rate pattern must have existed, in addition to the known change in accumulation rate from ice cores. The glacial spatial accumulation-rate pattern would have had proportionally greater accumulation at the South Pole than now, compared with the Vostok and Dome C ice cores.

Published
2011
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19. Coupling of ice-shelf melting and buttressing is a key process in ice-sheets dynamics

Author

Gagliardini, O., Durand, Geoffroy, Zwinger, T., Hindmarsh, R. C. A., Le Meur, E., Laboratoire de glaciologie et géophysique de l'environnement (LGGE), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Scientific Computing Ltd (CSC), CLIPS, EDGE, Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), ANR-06-VULN-0016,DACOTA,Dynamique des glaciers côtiers et rôle sur le bilan de masse global de l'Antarctique zone atelier du glacier de l'Astrolabe, Terre Adélie(2006), European Project: 226375,EC:FP7:ENV,FP7-ENV-2008-1,ICE2SEA(2009), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), ANR‐06‐VULN‐016‐01,ANR‐06‐VULN‐016‐01, Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG)

Subjects
Meteorology and Climatology, Glaciology, Cryosphere: Ice shelves, [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology, Cryosphere: Modeling (1952), Cryosphere: Dynamics
Abstract

Increase in ice-shelf melting is generally presumed to have triggered recent coastal ice-sheet thinning. Using a full-Stokes finite element model which includes a proper description of the grounding line dynamics, we investigate the impact of melting below ice shelves. We argue that the influence of ice-shelf melting on the ice-sheet dynamics induces a complex response, and the first naive view that melting inevitably leads to loss of grounded ice is erroneous. We demonstrate that melting acts directly on the magnitude of the buttressing force by modifying both the area experiencing lateral resistance and the ice-shelf velocity, indicating that the decrease of back stress imposed by the ice-shelf is the prevailing cause of inland dynamical thinning. We further show that feedback from melting and buttressing forces can lead to nontrivial results, as an increase in the average melt rate may lead to inland ice thickening and grounding line advance. Citation: Gagliardini, O., G. Durand, T. Zwinger, R. C. A. Hindmarsh, and E. Le Meur (2010), Coupling of ice-shelf melting and buttressing is a key process in ice-sheets dynamics, Geophys. Res. Lett., 37, L14501, doi:10.1029/2010GL043334.

Published
2010
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21. Benchmark experiments for higher-order and full Stokes ice sheet models (ISMIP-HOM)

Author

Pattyn, F., Perichon, L., Aschwanden, A., Breuer, B., De Smedt, B., Gagliardini, O., Gudmundsson, G. H., Hindmarsh, R., Hubbard, A., Johnson, J. V., Kleiner, T., Konovalov, Y., Martin, C., Payne, A. J., Pollard, D., Price, S., Rückamp, M., Saito, F., Soucek, O., Sugiyama, S., Zwinger, T., Laboratoire de Glaciologie, Université Libre de Bruxelles [Bruxelles] (ULB), Institute for Atmospheric and Climate Science [Zürich] (IAC), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich), Institute for Geophysics, Westfälische Wilhelms-Universität Münster (WWU), Vakgroep Geografie, Vrije Universiteit [Brussels] (VUB), Laboratoire de glaciologie et géophysique de l'environnement (LGGE), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS), Physical Science Division, British Antarctic Survey (BAS), Natural Environment Research Council (NERC)-Natural Environment Research Council (NERC), Centre for Glaciology, Institute of Geography and Earth Sciences, Department of Computer Science [New York], Columbia University [New York], Moscow Engineering Physics Institute, Bristol Glaciology Centre, School of Geographical Sciences, Earth and Environmental Systems Institute, College of Earth and Mineral Sciences, Frontier Research Center for Global Change (FRCGC), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Department of Geophysics, Charles University [Prague], Institute of Low Temperature Science, Hokkaido University, Scientific Computing Ltd (CSC), Université libre de Bruxelles (ULB), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Vrije Universiteit Brussel (VUB), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Pennsylvania State University (Penn State), Penn State System-Penn State System, Charles University [Prague] (CU), Institute of Low Temperature Science [Sapporo], Hokkaido University [Sapporo, Japan], and EGU, Publication

Subjects
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, 010504 meteorology & atmospheric sciences, [SDU.OCEAN] Sciences of the Universe [physics]/Ocean, Atmosphere, [SDU.STU] Sciences of the Universe [physics]/Earth Sciences, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, 010103 numerical & computational mathematics, 0101 mathematics, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, 01 natural sciences, [SDU.ENVI] Sciences of the Universe [physics]/Continental interfaces, environment, 0105 earth and related environmental sciences
Abstract

We present the results of the first ice sheet model intercomparison project for higher-order and full Stokes ice sheet models. These models are validated in a series of six benchmark experiments of which one has an analytical solution under simplifying assumptions. Five of the tests are diagnostic and one experiment is prognostic or time dependent, for both 2-D and 3-D geometries. The results show a good convergence of the different models even for high aspect ratios. A clear distinction can be made between higher-order models and those that solve the full system of equations. The latter show a significantly better agreement with each other as well as with analytical solutions, which demonstrates that they are hardly influenced by the used numerics.

Published
2008

23. Exploration of Ellsworth Subglacial Lake: a concept paper on the development, organisation and execution of an experiment to explore, measure and sample the environment of a West Antarctic subglacial lake

Author

Siegert, M.J., Behar, A., Bentley, M., Blake, D., Christoffersen, P., Cockell, C., Corr, H., Cullen, D.C., Edwards, H., Ellery, A., Ellis-Evans, C., Griffiths, G., Hindmarsh, R., Hodgson, D.A., King, E., Lamb, H., Lane, L., Makinson, K., Mowlem, M., Parnell, J., Pearce, D.A., Priscu, J., Rivera, A., Sephton, M.A., Sims, M.R., Smith, A.R., Tranter, M., Wadham, J.L., Wilson, G., and Woodward, J.

Abstract

Antarctic subglacial lakes have, over the past few years, been hypothesised to house unique forms of life and hold detailed sedimentary records of past climate change. Testing this hypothesis requires in situ examinations. The direct measurement of subglacial lakes has been considered ever since the largest and best-known lake, named Lake Vostok, was identified as having a deep water-column. The Subglacial Antarctic Lake Environments (SALE) programme, set up by the Scientific Committee on Antarctic Research (SCAR) to oversee subglacial lakes research, state that prior exploration of smaller lakes would be a “prudent way forward”. Over 145 subglacial lakes are known to exist in Antarctica, but one lake in West Antarctica, officially named Ellsworth Subglacial Lake (referred to hereafter as Lake Ellsworth), stands out as a candidate for early exploration. A consortium of over 20 scientists from seven countries and 14 institutions has been assembled to plan the exploration of Lake Ellsworth. An eight-year programme is envisaged: 3 years for a geophysical survey, 2 years for equipment development and testing, 1 year for field planning and operation, and 2 years for sample analysis and data interpretation. The science experiment is simple in concept but complex in execution. Lake Ellsworth will be accessed using hot water drilling. Once lake access is achieved, a probe will be lowered down the borehole and into the lake. The probe will contain a series of instruments to measure biological, chemical and physical characteristics of the lake water and sediments, and will utilise a tether to the ice surface through which power, communication and data will be transmitted. The probe will pass through the water column to the lake floor. The probe will then be pulled up and out of the lake, measuring its environment continually as this is done. Once at the ice surface, any water samples collected will be taken from the probe for laboratory analysis (to take place over subsequent years). The duration of the science mission, from deployment of the probe to its retrieval, is likely to take between 24 and 36 h. Measurements to be taken by the probe will provide data about the following: depth, pressure, conductivity and temperature; pH levels; biomolecules (using life marker chips); anions (using a chemical analyzer); visualisation of the environment (using cameras and light sources); dissolved gases (using chromatography); and morphology of the lake floor and sediment structures (using sonar). After the probe has been retrieved, a sediment corer may be dropped into the lake to recover material from the lake floor. Finally, if time permits, a thermistor string may be left in the lake water to take time-dependent measurements of the lake’s water column over subsequent years. Given that the comprehensive geophysical survey of the lake will take place in two seasons during 2007–2009, a two-year instrument and logistic development phase from 2008 (after the lake’s bathymetry has been assessed) makes it possible that the exploration of Lake Ellsworth could take place at the beginning of the next decade.

Published
2007

24. Subglacial Lake Ellsworth: A candidate for in situ exploration in West Antarctica

Author

Siegert, M. J., Hindmarsh, R., Corr, H., Smith, A., Woodward, J., King, E. C., Payne, A. J., and Joughin, I.

Abstract

Radio-echo sounding reveals a 10 km-long lake beneath ∼3.4 km of ice near the Ellsworth Mountains in West Antarctica, 20 km from the ice divide. Subglacial Lake Ellsworth is located within a distinct topographic hollow, which is ∼1.5 km deeper than the surrounding bed. Judging by bed slopes flanking the lake, the water depth is at least 10s of metres. Calculations of basal temperature reveal the ice base to be warm both now and during full glacial periods. As the environments of subglacial lakes are broadly similar, life may be expected in Lake Ellsworth as in any other. Given this, its physical characteristics, and the fact that the West Antarctic Ice Sheet has been accessed on several occasions, Lake Ellsworth is an excellent candidate for in situ examination.

Published
2004
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25. Similarity of organized patterns in driving and basal stresses of Antarctic and Greenland ice sheets beneath extensive areas of basal sliding

Author

Sergienko, O.V., Creyts, T. T., Hindmarsh, R. C. A., Sergienko, O.V., Creyts, T. T., and Hindmarsh, R. C. A.

Abstract

The rate of ice transport from the interior of ice sheets to their margins, and hence the rate with which it contributes to sea level, is determined by the balance of driving stress, basal resistance and ice internal deformation. Using recent high resolution observations of the Antarctic and Greenland ice sheets, we compute driving stress and ice deformation velocities, inferring basal traction by inverse techniques. The results reveal broad scale organization in 5–20 km band-like patterns inboth the driving and basal shear stresses located in zones with substantial basal sliding. Both ice sheets experience basal sliding over areas substantially larger than previously recognized. The likely cause of the spatial patterns is the development of a band-like structure in the basal shear stress distribution that is the results of pattern-forming instabilities related to subglacial water. The similarity of patterns on the Greenland and Antarctic Ice Sheets suggests the flow of ice sheets is controlled by the same fundamental processes operating at their base, which control ice-sheet sliding and are highly variable on relatively short spatial and temporal scales, with poor predictability. This has far-reaching implications for understanding of the current and projection of the future ice sheets’ evolution.

Published
2014

27. Probe Technology for the Direct Measurement and Sampling of Ellsworth Subglacial Lake

Author

Mowlem, Matthew C., Tsaloglou, Maria Nefeli, Waugh, Edward M., Floquet, Cedric F.A., Saw, Kevin, Fowler, Lee, Brown, Robin, Pearce, David, Wyatt, James B., Beaton, Alexander D., Brito, Mario P., Hodgson, Dominic A., Griffiths, Gwyn, Bentley, M., Blake, D., Capper, L., Clarke, R., Cockell, C., Corr, H., Harris, W., Hill, C., Hindmarsh, R., King, E., Lamb, H., Maher, B., Makinson, K., Parnell, J., Priscu, J., Rivera, A., Ross, N., Siegert, M. J., Smith, A., Tait, A., Tranter, M., Wadham, J., Whalley, B., Woodward, J., Mowlem, Matthew C., Tsaloglou, Maria Nefeli, Waugh, Edward M., Floquet, Cedric F.A., Saw, Kevin, Fowler, Lee, Brown, Robin, Pearce, David, Wyatt, James B., Beaton, Alexander D., Brito, Mario P., Hodgson, Dominic A., Griffiths, Gwyn, Bentley, M., Blake, D., Capper, L., Clarke, R., Cockell, C., Corr, H., Harris, W., Hill, C., Hindmarsh, R., King, E., Lamb, H., Maher, B., Makinson, K., Parnell, J., Priscu, J., Rivera, A., Ross, N., Siegert, M. J., Smith, A., Tait, A., Tranter, M., Wadham, J., Whalley, B., and Woodward, J.

Abstract

The direct measurement and sampling of Ellsworth Subglacial Lake is a multidisciplinary investigation of life in extreme environments and West Antarctic ice sheet history. The project's aims are (1) to determine whether, and in what form, microbial life exists in Antarctic subglacial lakes and (2) to reveal the post-Pliocene history of the West Antarctic Ice Sheet. A U.K. consortium has planned an extensive logistics and equipment development program that will deliver the necessary resources. This will include hot water drill technology for lake access through approximately 3.2 km of ice, a probe to make measurements with sensors and to collect water and sediment samples, and a percussion corer to acquire an ~3-4 m sediment core. This chapter details the requirements and early stages of design and development of the probe system. This includes the instrumentation package, water samplers, and a mini gravity corer mounted on the front of the probe. Initial design concepts for supporting equipment required at the drill site to deploy and operate the probe are also described. A review of the literature describing relevant technology is presented. The project will implement environmental protection in line with principles set out by the Scientific Committee on Antarctic Research.

Published
2013

28. Grounding line transient response in marine ice sheet models

Author

UJF - Grenoble 1/CNRS - Laboratoire de Glaciologie et Géophysique de l’Environnement, Université Libre de Bruxelles - Laboratoire de Glaciologie, British Antarctic Survey - Natural Environment Research Council, Institut Universitaire de France - Institut Universitaire de France, CSC-IT Center for Science Ltd. - CSC-IT Center for Science Ltd., UCL - SST/ELI/ELIC - Earth & Climate, Drouet, A. S., Docquier, David, Durand, G., Hindmarsh, R., Pattyn, F., Gagliardini, O., Zwinger, T., UJF - Grenoble 1/CNRS - Laboratoire de Glaciologie et Géophysique de l’Environnement, Université Libre de Bruxelles - Laboratoire de Glaciologie, British Antarctic Survey - Natural Environment Research Council, Institut Universitaire de France - Institut Universitaire de France, CSC-IT Center for Science Ltd. - CSC-IT Center for Science Ltd., UCL - SST/ELI/ELIC - Earth & Climate, Drouet, A. S., Docquier, David, Durand, G., Hindmarsh, R., Pattyn, F., Gagliardini, O., and Zwinger, T.

Abstract

Marine ice-sheet stability is mostly controlled by the dynamics of the grounding line, i.e. the junction between the grounded ice sheet and the floating ice shelf. Grounding line migration has been investigated within the framework of MISMIP (Marine Ice Sheet Model Intercomparison Project), which mainly aimed at investigating steady state solutions. Here we focus on transient behaviour, executing short-term simulations (200 yr) of a steady ice sheet perturbed by the release of the buttressing restraint exerted by the ice shelf on the grounded ice upstream. The transient grounding line behaviour of four different flowline ice-sheet models has been compared. The models differ in the physics implemented (full Stokes and shallow shelf approximation), the numerical approach, as well as the grounding line treatment. Their overall response to the loss of buttressing is found to be broadly consistent in terms of grounding line position, rate of surface elevation change and surface velocity. However, still small differences appear for these latter variables, and they can lead to large discrepancies (> 100%) observed in terms of ice sheet contribution to sea level when cumulated over time. Despite the recent important improvements of marine ice-sheet models in their ability to compute steady state configurations, our results question the capacity of these models to compute short-term reliable sea-level rise projections.

Published
2013

29. Grounding line transient response in marine ice sheet models

Author

Drouet, A. S., Docquier, D., Durand, G., Hindmarsh, R., Pattyn, F., Gagliardini, O., Zwinger, T., Drouet, A. S., Docquier, D., Durand, G., Hindmarsh, R., Pattyn, F., Gagliardini, O., and Zwinger, T.

Abstract

Marine ice-sheet stability is mostly controlled by the dynamics of the grounding line, i.e. the junction between the grounded ice sheet and the floating ice shelf. Grounding line migration has been investigated within the framework of MISMIP (Marine Ice Sheet Model Intercomparison Project), which mainly aimed at investigating steady state solutions. Here we focus on transient behaviour, executing short-term simulations (200 yr) of a steady ice sheet perturbed by the release of the buttressing restraint exerted by the ice shelf on the grounded ice upstream. The transient grounding line behaviour of four different flowline ice-sheet models has been compared. The models differ in the physics implemented (full Stokes and shallow shelf approximation), the numerical approach, as well as the grounding line treatment. Their overall response to the loss of buttressing is found to be broadly consistent in terms of grounding line position, rate of surface elevation change and surface velocity. However, still small differences appear for these latter variables, and they can lead to large discrepancies (> 100%) observed in terms of ice sheet contribution to sea level when cumulated over time. Despite the recent important improvements of marine ice-sheet models in their ability to compute steady state configurations, our results question the capacity of these models to compute short-term reliable sea-level rise projections.

Published
2013

30. Getting around Antarctica: New high-resolution mappings of the grounded and freely-floating boundaries of the Antarctic ice sheet created for the International Polar Year

Author

Bindschadler, R., Choi, H., Wichlacz, A., Bingham, B., Bohlander, J., Brunt, K., Corr, H., Drews, Reinhard, Fricker, H., Hall, M., Hindmarsh, R., Kohler, J., Padman, L., Rack, Wolfgang, Rotschky, G., Urbini, S., Vornberger, P., Young, N., Bindschadler, R., Choi, H., Wichlacz, A., Bingham, B., Bohlander, J., Brunt, K., Corr, H., Drews, Reinhard, Fricker, H., Hall, M., Hindmarsh, R., Kohler, J., Padman, L., Rack, Wolfgang, Rotschky, G., Urbini, S., Vornberger, P., and Young, N.

Abstract

The boundary of grounded ice and the location of ice transitioning to a freely floating state are mapped at 15‐m resolution around the entire continent of Antarctica. These data products are produced by participants of the International Polar Year project ASAID using customized software combining Landsat‐7 imagery and ICESat laser altimetry. The grounded ice boundary is 53,610 km long; 74% of it abuts to floating ice shelves or outlet glaciers, 19% is adjacent to open or sea‐ice covered ocean, and 7% of the boundary are land terminations with bare rock. Elevations along each line are selected from 6 candidate digital elevation models: two created from the input ICESat laser altimetry and Landsat data, two from stereo satellite imagery, and two from compilations of primarily radar altimetry. Elevation selection and an assignment of confidence in the elevation value are based on agreement with ICESat elevation values and shape of the surface inferred from the Landsat imagery. Elevations along the freely‐floating boundary (called the hydrostatic line) are converted to ice thicknesses by applying a firn‐correction factor and a flotation criterion. The relationship between the seaward offset of the hydrostatic line from the grounding line only weakly matches a prediction based on beam theory. Airborne data are used to validate the technique of grounding line mapping, elevation selection and ice thickness derivation. The mapped products along with the customized software to generate them and a variety of intermediate products are available from the National Snow and Ice Data Center.

Published
2011

31. Probe technology for the direct measurement and sampling of Ellsworth Subglacial Lake

Author

Siegert, Martin J, Kennicutt, Mahlon C., II, Bindschadler, Robert A., Mowlem, M., Tsaloglou, M-N., Waugh, E., Floquet, C.F.A., Saw, K., Fowler, L., Brown, R., Pearce, D., Wyatt, J., Beaton, A.D., Brito, M.P., Hodgson, D., Griffiths, G., Bentley, M., Blake, D., Campbell, H., Capper, L., Clarke, R., Cockell, C., Corr, H., Harris, W., Hill, C., Hindmarsh, R., King, E., Lamb, H., Maher, B., Makinson, K., Parnell, J., Priscu, J., Rivera, A., Ross, N., Siegert, M.J., Smith, A., Tait, A., Tranter, M., Wadham, J., Whalley, B., Woodward, J., Siegert, Martin J, Kennicutt, Mahlon C., II, Bindschadler, Robert A., Mowlem, M., Tsaloglou, M-N., Waugh, E., Floquet, C.F.A., Saw, K., Fowler, L., Brown, R., Pearce, D., Wyatt, J., Beaton, A.D., Brito, M.P., Hodgson, D., Griffiths, G., Bentley, M., Blake, D., Campbell, H., Capper, L., Clarke, R., Cockell, C., Corr, H., Harris, W., Hill, C., Hindmarsh, R., King, E., Lamb, H., Maher, B., Makinson, K., Parnell, J., Priscu, J., Rivera, A., Ross, N., Siegert, M.J., Smith, A., Tait, A., Tranter, M., Wadham, J., Whalley, B., and Woodward, J.

Abstract

The direct measurement and sampling of Ellsworth Subglacial Lake is a multidisciplinary investigation of life in extreme environments and West Antarctic ice sheet history. The project's aims are (1) to determine whether, and in what form, microbial life exists in Antarctic subglacial lakes and (2) to reveal the post-Pliocene history of the West Antarctic Ice Sheet. A U.K. consortium has planned an extensive logistics and equipment development program that will deliver the necessary resources. This will include hot water drill technology for lake access through approximately 3.2 km of ice, a probe to make measurements with sensors and to collect water and sediment samples, and a percussion corer to acquire an ˜3–4 m sediment core. This chapter details the requirements and early stages of design and development of the probe system. This includes the instrumentation package, water samplers, and a mini gravity corer mounted on the front of the probe. Initial design concepts for supporting equipment required at the drill site to deploy and operate the probe are also described. A review of the literature describing relevant technology is presented. The project will implement environmental protection in line with principles set out by the Scientific Committee on Antarctic Research.

Published
2011

32. Ellsworth Subglacial Lake, West Antarctica:A review of its history and recent field campaigns

Author

Ross, N., Siegert, M. J., Rivera, A., Bentley, M. J., Blake, D., Capper, L., Clarke, R., Cockell, C. S., Corr, H. F.J., Harris, W., Hill, C., Hindmarsh, R. C.A., Hodgson, D. A., King, E. C., Lamb, H., Maher, B., Makinson, K., Mowlem, M., Parnell, J., Pearce, D. A., Priscu, J., Smith, A. M., Tait, A., Tranter, M., Wadham, J. L., Whalley, W. B., Woodward, J., Ross, N., Siegert, M. J., Rivera, A., Bentley, M. J., Blake, D., Capper, L., Clarke, R., Cockell, C. S., Corr, H. F.J., Harris, W., Hill, C., Hindmarsh, R. C.A., Hodgson, D. A., King, E. C., Lamb, H., Maher, B., Makinson, K., Mowlem, M., Parnell, J., Pearce, D. A., Priscu, J., Smith, A. M., Tait, A., Tranter, M., Wadham, J. L., Whalley, W. B., and Woodward, J.

Abstract

Ellsworth Subglacial Lake, first observed in airborne radio echo sounding data acquired in 1978, is located within a long, deep subglacial trough within the Ellsworth Subglacial Highlands of West Antarctica. Geophysical surveys have characterized the lake, its subglacial catchment, and the thickness, structure, and flow of the overlying ice sheet. Covering 28.9 km2, Ellsworth Subglacial Lake is located below 2.9 to 3.3 km of ice at depths of -1361 to -1030 m. Seismic reflection data have shown the lake to be up to 156 m deep and underlain by unconsolidated sediments. Ice sheet flow over the lake is characterized by low velocities (<6 m yr-1), flow convergence, and longitudinal extension. The lake appears to be in steady state, although the hydrological balance may vary over glacial-interglacial cycles. Direct access, measurement, and sampling of Ellsworth Subglacial Lake are planned for the 2012/2013 Antarctic field season. The aims of this access experiment are to determine (1) the presence, character, and maintenance of microbial life in Antarctic subglacial lakes and (2) the Quaternary history of the West Antarctic ice sheet. Geophysical data have been used to define a preferred lake access site. The factors that make this location suitable for exploration are (1) a relatively thin overlying ice column (~3.1 km), (2) a significant measured water depth (~143 m), (3) >2 m of sediment below the lake floor, (4) water circulation modeling suggesting a melting ice-water interface, and (5) coring that can target the deepest point of the lake floor away from marginal, localized sediment sources.

Published
2011

33. Ellsworth Subglacial Lake, West Antarctica : A review of its history and recent field campaigns

Author

Ross, N., Siegert, M. J., Rivera, A., Bentley, M. J., Blake, D., Capper, L., Clarke, R., Cockell, C. S., Corr, H. F.J., Harris, W., Hill, C., Hindmarsh, R. C.A., Hodgson, D. A., King, E. C., Lamb, H., Maher, B., Makinson, K., Mowlem, M., Parnell, J., Pearce, D. A., Priscu, J., Smith, A. M., Tait, A., Tranter, M., Wadham, J. L., Whalley, W. B., Woodward, J., Ross, N., Siegert, M. J., Rivera, A., Bentley, M. J., Blake, D., Capper, L., Clarke, R., Cockell, C. S., Corr, H. F.J., Harris, W., Hill, C., Hindmarsh, R. C.A., Hodgson, D. A., King, E. C., Lamb, H., Maher, B., Makinson, K., Mowlem, M., Parnell, J., Pearce, D. A., Priscu, J., Smith, A. M., Tait, A., Tranter, M., Wadham, J. L., Whalley, W. B., and Woodward, J.

Abstract

Ellsworth Subglacial Lake, first observed in airborne radio echo sounding data acquired in 1978, is located within a long, deep subglacial trough within the Ellsworth Subglacial Highlands of West Antarctica. Geophysical surveys have characterized the lake, its subglacial catchment, and the thickness, structure, and flow of the overlying ice sheet. Covering 28.9 km2, Ellsworth Subglacial Lake is located below 2.9 to 3.3 km of ice at depths of -1361 to -1030 m. Seismic reflection data have shown the lake to be up to 156 m deep and underlain by unconsolidated sediments. Ice sheet flow over the lake is characterized by low velocities (<6 m yr-1), flow convergence, and longitudinal extension. The lake appears to be in steady state, although the hydrological balance may vary over glacial-interglacial cycles. Direct access, measurement, and sampling of Ellsworth Subglacial Lake are planned for the 2012/2013 Antarctic field season. The aims of this access experiment are to determine (1) the presence, character, and maintenance of microbial life in Antarctic subglacial lakes and (2) the Quaternary history of the West Antarctic ice sheet. Geophysical data have been used to define a preferred lake access site. The factors that make this location suitable for exploration are (1) a relatively thin overlying ice column (~3.1 km), (2) a significant measured water depth (~143 m), (3) >2 m of sediment below the lake floor, (4) water circulation modeling suggesting a melting ice-water interface, and (5) coring that can target the deepest point of the lake floor away from marginal, localized sediment sources.

Published
2011

34. Manifestation of ice properties and dynamics in radar stratigraphy: Berkner Island ice saddle as a case study

Author

Eisen, Olaf, Martin, C., Blindow, N., Steinhage, Daniel, Hindmarsh, R., Eisen, Olaf, Martin, C., Blindow, N., Steinhage, Daniel, and Hindmarsh, R.

Abstract

Internal radar layers in ice sheets provide an indirect, but spatially-continuous record of ice flow and physical properties.Ground-based radar data recorded along the ridge of Berkner Island, Antarctica, reveals the presence of an isochrone arch in the vicinity of the saddle between the two domes (Thyssenhhe in the South and Reinwarthhhe in the North), upstream of McCarthy inlet to the East.The data show the isochrone arch between a two-way traveltime of about 0.3 us (30 m) to 5.2 us (~450 m), with an overall ice thickness of 11.2 us (950 m).At a depth of about 3.5 us (310 m) the isochrone arch changes its signature: it splits from a single bump to a double bump, with a separation of the anticlines of about 300 m.This oberservation has several implications.First, as isochrone arches were so far observed at ice domes and divides of zero along-divide flow, where deviatoric stresses are low (a "Raymond" bump), this should also be the case at the saddle point.Second, appearance of a double bumps are assumed to be an indicator of a strongly evolved crystal fabric at larger depth.Third, as the double bump appears at rather shallow depths (35% of the ice thickness) compared to other sites, thinning during the last millenia might have occured.The topography of a saddle is a very demanding three-dimensional composite scenario to test rheological assumptions.To analyse the influence of ice flow and fabric characteristics on internal layer architecture at the saddle, we employ a three-dimensional time-dependent anisotropic Full Stokes model that considers strain-induced fabric evolution.

Published
2008

35. Where to find 1.5 million yr old ice for the IPICS &quot;Oldest-Ice&quot; ice core

Author

Fischer, H., primary, Severinghaus, J., additional, Brook, E., additional, Wolff, E., additional, Albert, M., additional, Alemany, O., additional, Arthern, R., additional, Bentley, C., additional, Blankenship, D., additional, Chappellaz, J., additional, Creyts, T., additional, Dahl-Jensen, D., additional, Dinn, M., additional, Frezzotti, M., additional, Fujita, S., additional, Gallee, H., additional, Hindmarsh, R., additional, Hudspeth, D., additional, Jugie, G., additional, Kawamura, K., additional, Lipenkov, V., additional, Miller, H., additional, Mulvaney, R., additional, Parrenin, F., additional, Pattyn, F., additional, Ritz, C., additional, Schwander, J., additional, Steinhage, D., additional, van Ommen, T., additional, and Wilhelms, F., additional

Published
2013
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36. Where to find 1.5 million yr old ice for the IPICS "Oldest Ice" ice core

Author

Fischer, H., primary, Severinghaus, J., additional, Brook, E., additional, Wolff, E., additional, Albert, M., additional, Alemany, O., additional, Arthern, R., additional, Bentley, C., additional, Blankenship, D., additional, Chappellaz, J., additional, Creyts, T., additional, Dahl-Jensen, D., additional, Dinn, M., additional, Frezzotti, M., additional, Fujita, S., additional, Gallee, H., additional, Hindmarsh, R., additional, Hudspeth, D., additional, Jugie, G., additional, Kawamura, K., additional, Lipenkov, V., additional, Miller, H., additional, Mulvaney, R., additional, Pattyn, F., additional, Ritz, C., additional, Schwander, J., additional, Steinhage, D., additional, van Ommen, T., additional, and Wilhelms, F., additional

Published
2013
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38. Supplementary material to &quot;Bedmap2: improved ice bed, surface and thickness datasets for Antarctica&quot;

Author

Fretwell, P., primary, Pritchard, H. D., additional, Vaughan, D. G., additional, Bamber, J. L., additional, Barrand, N. E., additional, Bell, R., additional, Bianchi, C., additional, Bingham, R. G., additional, Blankenship, D. D., additional, Casassa, G., additional, Catania, G., additional, Callens, D., additional, Conway, H., additional, Cook, A. J., additional, Corr, H. F. J., additional, Damaske, D., additional, Damm, V., additional, Ferraccioli, F., additional, Forsberg, R., additional, Fujita, S., additional, Gogineni, P., additional, Griggs, J. A., additional, Hindmarsh, R. C. A., additional, Holmlund, P., additional, Holt, J. W., additional, Jacobel, R. W., additional, Jenkins, A., additional, Jokat, W., additional, Jordan, T., additional, King, E. C., additional, Kohler, J., additional, Krabill, W., additional, Riger-Kusk, M., additional, Langley, K. A., additional, Leitchenkov, G., additional, Leuschen, C., additional, Luyendyk, B. P., additional, Matsuoka, K., additional, Nogi, Y., additional, Nost, O. A., additional, Popov, S. V., additional, Rignot, E., additional, Rippin, D. M., additional, Riviera, A., additional, Roberts, J., additional, Ross, N., additional, Siegert, M. J., additional, Smith, A. M., additional, Steinhage, D., additional, Studinger, M., additional, Sun, B., additional, Tinto, B. K., additional, Welch, B. C., additional, Young, D. A., additional, Xiangbin, C., additional, and Zirizzotti, A., additional

Published
2012
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39. Bedmap2: improved ice bed, surface and thickness datasets for Antarctica

Author

Fretwell, P., primary, Pritchard, H. D., additional, Vaughan, D. G., additional, Bamber, J. L., additional, Barrand, N. E., additional, Bell, R., additional, Bianchi, C., additional, Bingham, R. G., additional, Blankenship, D. D., additional, Casassa, G., additional, Catania, G., additional, Callens, D., additional, Conway, H., additional, Cook, A. J., additional, Corr, H. F. J., additional, Damaske, D., additional, Damm, V., additional, Ferraccioli, F., additional, Forsberg, R., additional, Fujita, S., additional, Gogineni, P., additional, Griggs, J. A., additional, Hindmarsh, R. C. A., additional, Holmlund, P., additional, Holt, J. W., additional, Jacobel, R. W., additional, Jenkins, A., additional, Jokat, W., additional, Jordan, T., additional, King, E. C., additional, Kohler, J., additional, Krabill, W., additional, Riger-Kusk, M., additional, Langley, K. A., additional, Leitchenkov, G., additional, Leuschen, C., additional, Luyendyk, B. P., additional, Matsuoka, K., additional, Nogi, Y., additional, Nost, O. A., additional, Popov, S. V., additional, Rignot, E., additional, Rippin, D. M., additional, Riviera, A., additional, Roberts, J., additional, Ross, N., additional, Siegert, M. J., additional, Smith, A. M., additional, Steinhage, D., additional, Studinger, M., additional, Sun, B., additional, Tinto, B. K., additional, Welch, B. C., additional, Young, D. A., additional, Xiangbin, C., additional, and Zirizzotti, A., additional

Published
2012
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41. Results of the Marine Ice Sheet Model Intercomparison Project, MISMIP

Author

Pattyn, F., primary, Schoof, C., additional, Perichon, L., additional, Hindmarsh, R. C. A., additional, Bueler, E., additional, de Fleurian, B., additional, Durand, G., additional, Gagliardini, O., additional, Gladstone, R., additional, Goldberg, D., additional, Gudmundsson, G. H., additional, Huybrechts, P., additional, Lee, V., additional, Nick, F. M., additional, Payne, A. J., additional, Pollard, D., additional, Rybak, O., additional, Saito, F., additional, and Vieli, A., additional

Published
2012
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44. Getting around Antarctica: new high-resolution mappings of the grounded and freely-floating boundaries of the Antarctic ice sheet created for the International Polar Year

Author

Bindschadler, R., primary, Choi, H., additional, Wichlacz, A., additional, Bingham, R., additional, Bohlander, J., additional, Brunt, K., additional, Corr, H., additional, Drews, R., additional, Fricker, H., additional, Hall, M., additional, Hindmarsh, R., additional, Kohler, J., additional, Padman, L., additional, Rack, W., additional, Rotschky, G., additional, Urbini, S., additional, Vornberger, P., additional, and Young, N., additional

Published
2011
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47. Benchmark experiments for higher-order and full-Stokes ice sheet models (ISMIP–HOM)

Author

Pattyn, F., primary, Perichon, L., additional, Aschwanden, A., additional, Breuer, B., additional, de Smedt, B., additional, Gagliardini, O., additional, Gudmundsson, G. H., additional, Hindmarsh, R. C. A., additional, Hubbard, A., additional, Johnson, J. V., additional, Kleiner, T., additional, Konovalov, Y., additional, Martin, C., additional, Payne, A. J., additional, Pollard, D., additional, Price, S., additional, Rückamp, M., additional, Saito, F., additional, Souček, O., additional, Sugiyama, S., additional, and Zwinger, T., additional

Published
2008
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48. Supplementary material to "Benchmark experiments for higher-order and full Stokes ice sheet models (ISMIP-HOM)"

Author

Pattyn, F., primary, Perichon, L., additional, Aschwanden, A., additional, Breuer, B., additional, de Smedt, B., additional, Gagliardini, O., additional, Gudmundsson, G. H., additional, Hindmarsh, R., additional, Hubbard, A., additional, Johnson, J. V., additional, Kleiner, T., additional, Konovalov, Y., additional, Martin, C., additional, Payne, A. J., additional, Pollard, D., additional, Price, S., additional, Rückamp, M., additional, Saito, F., additional, Souček, O., additional, Sugiyama, S., additional, and Zwinger, T., additional

Published
2008
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49. Exploration of Ellsworth Subglacial Lake: a concept paper on the development, organisation and execution of an experiment to explore, measure and sample the environment of a West Antarctic subglacial lake

Author

Siegert, M.J., primary, Behar, A., additional, Bentley, M., additional, Blake, D., additional, Bowden, S., additional, Christoffersen, P., additional, Cockell, C., additional, Corr, H., additional, Cullen, D. C., additional, Edwards, H., additional, Ellery, A., additional, Ellis-Evans, C., additional, Griffiths, G., additional, Hindmarsh, R., additional, Hodgson, D. A., additional, King, E., additional, Lamb, H., additional, Lane, L., additional, Makinson, K., additional, Mowlem, M., additional, Parnell, J., additional, Pearce, D. A., additional, Priscu, J., additional, Rivera, A., additional, Sephton, M. A., additional, Sims, M. R., additional, Smith, A . M., additional, Tranter, M., additional, Wadham, J. L., additional, Wilson, G., additional, and Woodward, J., additional

Published
2006
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