The impact of lateral variations in lithospheric thickness on glacial isostatic adjustment in West Antarctica
Differences in predictions of Glacial Isostatic Adjustment (GIA) for Antarctica persist due to uncertainties in deglacial history and Earth rheology. The Earth models adopted in many GIA studies are defined by parameters that vary in the radial direction only and represent a global average Earth str...
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ftleedsuniv:oai:eprints.whiterose.ac.uk:138624 2023-05-15T13:57:46+02:00 The impact of lateral variations in lithospheric thickness on glacial isostatic adjustment in West Antarctica Nield, GA Whitehouse, PL Van der Wal, W Blank, B O'Donnell, JP Stuart, GW 2018-08-01 text https://eprints.whiterose.ac.uk/138624/ https://eprints.whiterose.ac.uk/138624/1/ggy158.pdf en eng Oxford University Press https://eprints.whiterose.ac.uk/138624/1/ggy158.pdf Nield, GA, Whitehouse, PL, Van der Wal, W et al. (3 more authors) (2018) The impact of lateral variations in lithospheric thickness on glacial isostatic adjustment in West Antarctica. Geophysical Journal International, 214 (2). pp. 811-824. ISSN 0956-540X cc_by_4 CC-BY Article NonPeerReviewed 2018 ftleedsuniv 2023-01-30T22:12:44Z Differences in predictions of Glacial Isostatic Adjustment (GIA) for Antarctica persist due to uncertainties in deglacial history and Earth rheology. The Earth models adopted in many GIA studies are defined by parameters that vary in the radial direction only and represent a global average Earth structure (referred to as 1-D Earth models). Oversimplifying the actual Earth structure leads to bias in model predictions in regions where Earth parameters differ significantly from the global average, such as West Antarctica. We investigate the impact of lateral variations in lithospheric thickness on GIA in Antarctica by carrying out two experiments that use different rheological approaches to define 3-D Earth models that include spatial variations in lithospheric thickness. The first experiment defines an elastic lithosphere with spatial variations in thickness inferred from seismic studies. We compare the results from this 3-D model with results derived from a 1-D Earth model that has a uniform lithospheric thickness defined as the average of the 3-D lithospheric thickness. Irrespective of the deglacial history and sublithospheric mantle viscosity, we find higher gradients of present-day uplift rates (i.e. higher amplitude and shorter wavelength) in West Antarctica when using the 3-D models, due to the thinner-than-1-D-average lithosphere prevalent in this region. The second experiment uses seismically inferred temperature as an input to a power-law rheology, thereby allowing the lithosphere to have a viscosity structure. Modelling the lithosphere with a power-law rheology results in a behaviour that is equivalent to a thinner lithosphere model, and it leads to higher amplitude and shorter wavelength deformation compared with the first experiment. We conclude that neglecting spatial variations in lithospheric thickness in GIA models will result in predictions of peak uplift and subsidence that are biased low in West Antarctica. This has important implications for ice-sheet modelling studies as the steeper gradients ... Article in Journal/Newspaper Antarc* Antarctica Ice Sheet West Antarctica White Rose Research Online (Universities of Leeds, Sheffield & York) West Antarctica |
institution |
Open Polar |
collection |
White Rose Research Online (Universities of Leeds, Sheffield & York) |
op_collection_id |
ftleedsuniv |
language |
English |
description |
Differences in predictions of Glacial Isostatic Adjustment (GIA) for Antarctica persist due to uncertainties in deglacial history and Earth rheology. The Earth models adopted in many GIA studies are defined by parameters that vary in the radial direction only and represent a global average Earth structure (referred to as 1-D Earth models). Oversimplifying the actual Earth structure leads to bias in model predictions in regions where Earth parameters differ significantly from the global average, such as West Antarctica. We investigate the impact of lateral variations in lithospheric thickness on GIA in Antarctica by carrying out two experiments that use different rheological approaches to define 3-D Earth models that include spatial variations in lithospheric thickness. The first experiment defines an elastic lithosphere with spatial variations in thickness inferred from seismic studies. We compare the results from this 3-D model with results derived from a 1-D Earth model that has a uniform lithospheric thickness defined as the average of the 3-D lithospheric thickness. Irrespective of the deglacial history and sublithospheric mantle viscosity, we find higher gradients of present-day uplift rates (i.e. higher amplitude and shorter wavelength) in West Antarctica when using the 3-D models, due to the thinner-than-1-D-average lithosphere prevalent in this region. The second experiment uses seismically inferred temperature as an input to a power-law rheology, thereby allowing the lithosphere to have a viscosity structure. Modelling the lithosphere with a power-law rheology results in a behaviour that is equivalent to a thinner lithosphere model, and it leads to higher amplitude and shorter wavelength deformation compared with the first experiment. We conclude that neglecting spatial variations in lithospheric thickness in GIA models will result in predictions of peak uplift and subsidence that are biased low in West Antarctica. This has important implications for ice-sheet modelling studies as the steeper gradients ... |
format |
Article in Journal/Newspaper |
author |
Nield, GA Whitehouse, PL Van der Wal, W Blank, B O'Donnell, JP Stuart, GW |
spellingShingle |
Nield, GA Whitehouse, PL Van der Wal, W Blank, B O'Donnell, JP Stuart, GW The impact of lateral variations in lithospheric thickness on glacial isostatic adjustment in West Antarctica |
author_facet |
Nield, GA Whitehouse, PL Van der Wal, W Blank, B O'Donnell, JP Stuart, GW |
author_sort |
Nield, GA |
title |
The impact of lateral variations in lithospheric thickness on glacial isostatic adjustment in West Antarctica |
title_short |
The impact of lateral variations in lithospheric thickness on glacial isostatic adjustment in West Antarctica |
title_full |
The impact of lateral variations in lithospheric thickness on glacial isostatic adjustment in West Antarctica |
title_fullStr |
The impact of lateral variations in lithospheric thickness on glacial isostatic adjustment in West Antarctica |
title_full_unstemmed |
The impact of lateral variations in lithospheric thickness on glacial isostatic adjustment in West Antarctica |
title_sort |
impact of lateral variations in lithospheric thickness on glacial isostatic adjustment in west antarctica |
publisher |
Oxford University Press |
publishDate |
2018 |
url |
https://eprints.whiterose.ac.uk/138624/ https://eprints.whiterose.ac.uk/138624/1/ggy158.pdf |
geographic |
West Antarctica |
geographic_facet |
West Antarctica |
genre |
Antarc* Antarctica Ice Sheet West Antarctica |
genre_facet |
Antarc* Antarctica Ice Sheet West Antarctica |
op_relation |
https://eprints.whiterose.ac.uk/138624/1/ggy158.pdf Nield, GA, Whitehouse, PL, Van der Wal, W et al. (3 more authors) (2018) The impact of lateral variations in lithospheric thickness on glacial isostatic adjustment in West Antarctica. Geophysical Journal International, 214 (2). pp. 811-824. ISSN 0956-540X |
op_rights |
cc_by_4 |
op_rightsnorm |
CC-BY |
_version_ |
1766265664572489728 |