A Non-steady Ice-sheet Model Incorporating Longitudinal Stresses: Application to the Adjustment of Interior Regions of an Ice Sheet to Changes in Sea Level
In order to study the effect of sea-level changes on inland ice sheets, a new ice-flow model has been developed that explicitly includes longitudinal stresses. Two-dimensional flow is assumed, and the flow-law parameter and longitudinal-deviatoric stress are taken to be weighted averages over depth....
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Institute of Polar Studies, The Ohio State University.
1984
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ftohiostateu:oai:kb.osu.edu:1811/51675 2023-05-15T13:38:14+02:00 A Non-steady Ice-sheet Model Incorporating Longitudinal Stresses: Application to the Adjustment of Interior Regions of an Ice Sheet to Changes in Sea Level Alley, Richard B. 1984 application/pdf http://hdl.handle.net/1811/51675 en_US eng Institute of Polar Studies, The Ohio State University. Institute of Polar Studies Report No. 84. Alley, Richard B. 1984. A Non-steady Ice-sheet Model Incorporating Longitudinal Stresses: Application to the Adjustment of Interior Regions of an Ice Sheet to Changes in Sea Level. Institute of Polar Studies Report No. 84, Institute of Polar Studies, The Ohio State University, 100 pages. 0078-415X http://hdl.handle.net/1811/51675 Copyright 1983; used by permission of the author. Ice sheet model Sea level Ice flow model Dome C East Antarctica Technical Report 1984 ftohiostateu 2020-08-22T19:23:33Z In order to study the effect of sea-level changes on inland ice sheets, a new ice-flow model has been developed that explicitly includes longitudinal stresses. Two-dimensional flow is assumed, and the flow-law parameter and longitudinal-deviatoric stress are taken to be weighted averages over depth. The flow-law equations for longitudinal and shear deformation are then averaged over thickness. The resulting equations, together with continuity and a bottom-sliding relation, form a simple one-dimensional system of equations that describes changes in ice-sheet configuration over time. Sea-level rise causes a wave of thinning to propagate upglacier in an ice sheet with terminal position controlled by sea level. The wave of thinning slows, diffuses, and is damped as it moves upglacier; thus, perturbations near the coast must be large and be long lasting to affect inland regions. Model calculations show that post-Wisconsinan sea-level rise has caused 110 m thinning at Dome C, East Antarctica, and that response is now 70 percent complete. Accumulation rate probably increased at the same time, however, and including this in the model reduces calculated thinning. For a 10 percent increase in accumulation rate from Wisconsinan to Holocene, there has been 75 m post-Wisconsinan thinning due to combined effects of sea-level rise and accumulation-rate increase. National Science Foundation Grant DPP-7920824A02. Report Antarc* Antarctica East Antarctica Ice Sheet Ohio State University (OSU): Knowledge Bank East Antarctica |
institution |
Open Polar |
collection |
Ohio State University (OSU): Knowledge Bank |
op_collection_id |
ftohiostateu |
language |
English |
topic |
Ice sheet model Sea level Ice flow model Dome C East Antarctica |
spellingShingle |
Ice sheet model Sea level Ice flow model Dome C East Antarctica Alley, Richard B. A Non-steady Ice-sheet Model Incorporating Longitudinal Stresses: Application to the Adjustment of Interior Regions of an Ice Sheet to Changes in Sea Level |
topic_facet |
Ice sheet model Sea level Ice flow model Dome C East Antarctica |
description |
In order to study the effect of sea-level changes on inland ice sheets, a new ice-flow model has been developed that explicitly includes longitudinal stresses. Two-dimensional flow is assumed, and the flow-law parameter and longitudinal-deviatoric stress are taken to be weighted averages over depth. The flow-law equations for longitudinal and shear deformation are then averaged over thickness. The resulting equations, together with continuity and a bottom-sliding relation, form a simple one-dimensional system of equations that describes changes in ice-sheet configuration over time. Sea-level rise causes a wave of thinning to propagate upglacier in an ice sheet with terminal position controlled by sea level. The wave of thinning slows, diffuses, and is damped as it moves upglacier; thus, perturbations near the coast must be large and be long lasting to affect inland regions. Model calculations show that post-Wisconsinan sea-level rise has caused 110 m thinning at Dome C, East Antarctica, and that response is now 70 percent complete. Accumulation rate probably increased at the same time, however, and including this in the model reduces calculated thinning. For a 10 percent increase in accumulation rate from Wisconsinan to Holocene, there has been 75 m post-Wisconsinan thinning due to combined effects of sea-level rise and accumulation-rate increase. National Science Foundation Grant DPP-7920824A02. |
format |
Report |
author |
Alley, Richard B. |
author_facet |
Alley, Richard B. |
author_sort |
Alley, Richard B. |
title |
A Non-steady Ice-sheet Model Incorporating Longitudinal Stresses: Application to the Adjustment of Interior Regions of an Ice Sheet to Changes in Sea Level |
title_short |
A Non-steady Ice-sheet Model Incorporating Longitudinal Stresses: Application to the Adjustment of Interior Regions of an Ice Sheet to Changes in Sea Level |
title_full |
A Non-steady Ice-sheet Model Incorporating Longitudinal Stresses: Application to the Adjustment of Interior Regions of an Ice Sheet to Changes in Sea Level |
title_fullStr |
A Non-steady Ice-sheet Model Incorporating Longitudinal Stresses: Application to the Adjustment of Interior Regions of an Ice Sheet to Changes in Sea Level |
title_full_unstemmed |
A Non-steady Ice-sheet Model Incorporating Longitudinal Stresses: Application to the Adjustment of Interior Regions of an Ice Sheet to Changes in Sea Level |
title_sort |
non-steady ice-sheet model incorporating longitudinal stresses: application to the adjustment of interior regions of an ice sheet to changes in sea level |
publisher |
Institute of Polar Studies, The Ohio State University. |
publishDate |
1984 |
url |
http://hdl.handle.net/1811/51675 |
geographic |
East Antarctica |
geographic_facet |
East Antarctica |
genre |
Antarc* Antarctica East Antarctica Ice Sheet |
genre_facet |
Antarc* Antarctica East Antarctica Ice Sheet |
op_relation |
Institute of Polar Studies Report No. 84. Alley, Richard B. 1984. A Non-steady Ice-sheet Model Incorporating Longitudinal Stresses: Application to the Adjustment of Interior Regions of an Ice Sheet to Changes in Sea Level. Institute of Polar Studies Report No. 84, Institute of Polar Studies, The Ohio State University, 100 pages. 0078-415X http://hdl.handle.net/1811/51675 |
op_rights |
Copyright 1983; used by permission of the author. |
_version_ |
1766103047373586432 |