Numerical modelling of ice-sheet dynamics across the Vostok subglacial lake, central East Antarctica
A numerical model of the ice-sheet / ice-shelf transformation was used to investigate ice-sheet dynamics across the large subglacial lake beneath Vostok station, central East Antarctica. European Remote-sensing Satellite (ERS-1) altimetry of the ice surface and 60 MHz radio-echo sounding (RES) of th...
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ftawi:oai:epic.awi.de:2080 2024-09-15T17:46:37+00:00 Numerical modelling of ice-sheet dynamics across the Vostok subglacial lake, central East Antarctica Mayer, Christoph Siegert, M. J. 2000 https://epic.awi.de/id/eprint/2080/ https://hdl.handle.net/10013/epic.12670 unknown Mayer, C. and Siegert, M. J. (2000) Numerical modelling of ice-sheet dynamics across the Vostok subglacial lake, central East Antarctica , Journal of Glaciology,vol. 46, no 153, pp. 197-205 . hdl:10013/epic.12670 EPIC3Journal of Glaciology,vol. 46, no 153, pp. 197-205, ISSN: 0022-1430 Article isiRev 2000 ftawi 2024-06-24T03:53:43Z A numerical model of the ice-sheet / ice-shelf transformation was used to investigate ice-sheet dynamics across the large subglacial lake beneath Vostok station, central East Antarctica. European Remote-sensing Satellite (ERS-1) altimetry of the ice surface and 60 MHz radio-echo sounding (RES) of the ice-sheet base and internal ice-sheet layering were used to develop a conceptual flowline across the ice sheet, which the model used as input. The model calculates horizontal and vertical velocities and stresses, from which particle flow paths can be obtained, and the ice-sheet temperature distribution. An inverse approach to modelling was adopted, where particle flow paths were forced to match those identified from internal RES layering. Results show that ice dynamics across the inflow grounding line are similar to an ice-sheet / ice-shelf transition. Model particle flow paths match internal RES layering when ice is (a) taken away from the ice base across the first 2 km of the flowline over the lake and (b) added to the base across the remainder of the lake. We contend that the process causing this transfer of ice is likely to be melting of ice and freezing of water at the ice-water interface. Other explanations, such as enhanced rates of accumulation over the grounding line, of three-dimensional convergent / divergent flow of ice are inconsistent with available measurements. Such melting and refreezing would be responsible for circulation and mixing of at least the surface layers of the lake water. Our model suggests that several tens of metres of refrozen "basal ice" would accrete from lake water to the ice sheet before the ice regrounds. Article in Journal/Newspaper Antarc* Antarctica Antarctica Journal East Antarctica Ice Sheet Ice Shelf Journal of Glaciology Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) |
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Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) |
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ftawi |
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description |
A numerical model of the ice-sheet / ice-shelf transformation was used to investigate ice-sheet dynamics across the large subglacial lake beneath Vostok station, central East Antarctica. European Remote-sensing Satellite (ERS-1) altimetry of the ice surface and 60 MHz radio-echo sounding (RES) of the ice-sheet base and internal ice-sheet layering were used to develop a conceptual flowline across the ice sheet, which the model used as input. The model calculates horizontal and vertical velocities and stresses, from which particle flow paths can be obtained, and the ice-sheet temperature distribution. An inverse approach to modelling was adopted, where particle flow paths were forced to match those identified from internal RES layering. Results show that ice dynamics across the inflow grounding line are similar to an ice-sheet / ice-shelf transition. Model particle flow paths match internal RES layering when ice is (a) taken away from the ice base across the first 2 km of the flowline over the lake and (b) added to the base across the remainder of the lake. We contend that the process causing this transfer of ice is likely to be melting of ice and freezing of water at the ice-water interface. Other explanations, such as enhanced rates of accumulation over the grounding line, of three-dimensional convergent / divergent flow of ice are inconsistent with available measurements. Such melting and refreezing would be responsible for circulation and mixing of at least the surface layers of the lake water. Our model suggests that several tens of metres of refrozen "basal ice" would accrete from lake water to the ice sheet before the ice regrounds. |
format |
Article in Journal/Newspaper |
author |
Mayer, Christoph Siegert, M. J. |
spellingShingle |
Mayer, Christoph Siegert, M. J. Numerical modelling of ice-sheet dynamics across the Vostok subglacial lake, central East Antarctica |
author_facet |
Mayer, Christoph Siegert, M. J. |
author_sort |
Mayer, Christoph |
title |
Numerical modelling of ice-sheet dynamics across the Vostok subglacial lake, central East Antarctica |
title_short |
Numerical modelling of ice-sheet dynamics across the Vostok subglacial lake, central East Antarctica |
title_full |
Numerical modelling of ice-sheet dynamics across the Vostok subglacial lake, central East Antarctica |
title_fullStr |
Numerical modelling of ice-sheet dynamics across the Vostok subglacial lake, central East Antarctica |
title_full_unstemmed |
Numerical modelling of ice-sheet dynamics across the Vostok subglacial lake, central East Antarctica |
title_sort |
numerical modelling of ice-sheet dynamics across the vostok subglacial lake, central east antarctica |
publishDate |
2000 |
url |
https://epic.awi.de/id/eprint/2080/ https://hdl.handle.net/10013/epic.12670 |
genre |
Antarc* Antarctica Antarctica Journal East Antarctica Ice Sheet Ice Shelf Journal of Glaciology |
genre_facet |
Antarc* Antarctica Antarctica Journal East Antarctica Ice Sheet Ice Shelf Journal of Glaciology |
op_source |
EPIC3Journal of Glaciology,vol. 46, no 153, pp. 197-205, ISSN: 0022-1430 |
op_relation |
Mayer, C. and Siegert, M. J. (2000) Numerical modelling of ice-sheet dynamics across the Vostok subglacial lake, central East Antarctica , Journal of Glaciology,vol. 46, no 153, pp. 197-205 . hdl:10013/epic.12670 |
_version_ |
1810494923912249344 |