Uplift rates from a new high-density GPS network in Palmer Land indicate significant late Holocene ice loss in the southwestern Weddell Sea

Martin Wolstencroft, Matt A. King, Pippa L Whitehouse, Michael J. Bentley, Grace A. Nield, Edward C. King, Malcolm McMillan, Andrew Shepherd, Valentina Roberta Barletta, Andrea Bordoni, Riccardo E.M. Riva, Olga Didova, Brian C. Gunter

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Abstract

The measurement of ongoing ice-mass loss and associated melt water contribution to sea-level change from regions such as West Antarctica is dependent on a combination of remote sensing methods. A key method, the measurement of changes in Earth's gravity via the GRACE satellite mission, requires a potentially large correction to account for the isostatic response of the solid Earth to ice-load changes since the Last Glacial Maximum. In this study, we combine glacial isostatic adjustment modelling with a new GPS dataset of solid Earth deformation for the southern Antarctic Peninsula to test the current understanding of ice history in this region. A sufficiently complete history of past ice-load change is required for glacial isostatic adjustment models to accurately predict the spatial variation of ongoing solid Earth deformation, once the independently-constrained effects of present-day ice mass loss have been accounted for. Comparisons between the GPS data and glacial isostatic adjustment model predictions reveal a substantial misfit. The misfit is localized on the southwestern Weddell Sea, where current ice models under-predict uplift rates by approximately 2 mm yr−1. This under-prediction suggests that either the retreat of the ice sheet grounding line in this region occurred significantly later in the Holocene than currently assumed, or that the region previously hosted more ice than currently assumed. This finding demonstrates the need for further fieldwork to obtain direct constraints on the timing of Holocene grounding line retreat in the southwestern Weddell Sea and that GRACE estimates of ice sheet mass balance will be unreliable in this region until this is resolved.
Original languageEnglish
JournalGeophysical Journal International
Volume203
Issue number1
Pages (from-to)737-754
ISSN0956-540X
DOIs
Publication statusPublished - 2015

Bibliographical note

Copyright: The Authors 2015. Published by Oxford University Press on behalf of The Royal Astronomical Society. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits
unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.

Keywords

  • Sea level change
  • Space geodetic surveys
  • Global change from geodesy
  • Glaciology
  • Antarctica

Cite this

Wolstencroft, M., King, M. A., Whitehouse, P. L., Bentley, M. J., Nield, G. A., King, E. C., ... Gunter, B. C. (2015). Uplift rates from a new high-density GPS network in Palmer Land indicate significant late Holocene ice loss in the southwestern Weddell Sea. Geophysical Journal International, 203(1), 737-754. https://doi.org/10.1093/gji/ggv327
Wolstencroft, Martin ; King, Matt A. ; Whitehouse, Pippa L ; Bentley, Michael J. ; Nield, Grace A. ; King, Edward C. ; McMillan, Malcolm ; Shepherd, Andrew ; Barletta, Valentina Roberta ; Bordoni, Andrea ; Riva, Riccardo E.M. ; Didova, Olga ; Gunter, Brian C. . / Uplift rates from a new high-density GPS network in Palmer Land indicate significant late Holocene ice loss in the southwestern Weddell Sea. In: Geophysical Journal International. 2015 ; Vol. 203, No. 1. pp. 737-754.
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abstract = "The measurement of ongoing ice-mass loss and associated melt water contribution to sea-level change from regions such as West Antarctica is dependent on a combination of remote sensing methods. A key method, the measurement of changes in Earth's gravity via the GRACE satellite mission, requires a potentially large correction to account for the isostatic response of the solid Earth to ice-load changes since the Last Glacial Maximum. In this study, we combine glacial isostatic adjustment modelling with a new GPS dataset of solid Earth deformation for the southern Antarctic Peninsula to test the current understanding of ice history in this region. A sufficiently complete history of past ice-load change is required for glacial isostatic adjustment models to accurately predict the spatial variation of ongoing solid Earth deformation, once the independently-constrained effects of present-day ice mass loss have been accounted for. Comparisons between the GPS data and glacial isostatic adjustment model predictions reveal a substantial misfit. The misfit is localized on the southwestern Weddell Sea, where current ice models under-predict uplift rates by approximately 2 mm yr−1. This under-prediction suggests that either the retreat of the ice sheet grounding line in this region occurred significantly later in the Holocene than currently assumed, or that the region previously hosted more ice than currently assumed. This finding demonstrates the need for further fieldwork to obtain direct constraints on the timing of Holocene grounding line retreat in the southwestern Weddell Sea and that GRACE estimates of ice sheet mass balance will be unreliable in this region until this is resolved.",
keywords = "Sea level change, Space geodetic surveys, Global change from geodesy, Glaciology, Antarctica",
author = "Martin Wolstencroft and King, {Matt A.} and Whitehouse, {Pippa L} and Bentley, {Michael J.} and Nield, {Grace A.} and King, {Edward C.} and Malcolm McMillan and Andrew Shepherd and Barletta, {Valentina Roberta} and Andrea Bordoni and Riva, {Riccardo E.M.} and Olga Didova and Gunter, {Brian C.}",
note = "Copyright: The Authors 2015. Published by Oxford University Press on behalf of The Royal Astronomical Society. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.",
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Wolstencroft, M, King, MA, Whitehouse, PL, Bentley, MJ, Nield, GA, King, EC, McMillan, M, Shepherd, A, Barletta, VR, Bordoni, A, Riva, REM, Didova, O & Gunter, BC 2015, 'Uplift rates from a new high-density GPS network in Palmer Land indicate significant late Holocene ice loss in the southwestern Weddell Sea', Geophysical Journal International, vol. 203, no. 1, pp. 737-754. https://doi.org/10.1093/gji/ggv327

Uplift rates from a new high-density GPS network in Palmer Land indicate significant late Holocene ice loss in the southwestern Weddell Sea. / Wolstencroft, Martin ; King, Matt A.; Whitehouse, Pippa L; Bentley, Michael J. ; Nield, Grace A.; King, Edward C. ; McMillan, Malcolm; Shepherd, Andrew; Barletta, Valentina Roberta; Bordoni, Andrea; Riva, Riccardo E.M. ; Didova, Olga ; Gunter, Brian C. .

In: Geophysical Journal International, Vol. 203, No. 1, 2015, p. 737-754.

Research output: Contribution to journalJournal articleResearchpeer-review

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T1 - Uplift rates from a new high-density GPS network in Palmer Land indicate significant late Holocene ice loss in the southwestern Weddell Sea

AU - Wolstencroft, Martin

AU - King, Matt A.

AU - Whitehouse, Pippa L

AU - Bentley, Michael J.

AU - Nield, Grace A.

AU - King, Edward C.

AU - McMillan, Malcolm

AU - Shepherd, Andrew

AU - Barletta, Valentina Roberta

AU - Bordoni, Andrea

AU - Riva, Riccardo E.M.

AU - Didova, Olga

AU - Gunter, Brian C.

N1 - Copyright: The Authors 2015. Published by Oxford University Press on behalf of The Royal Astronomical Society. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.

PY - 2015

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N2 - The measurement of ongoing ice-mass loss and associated melt water contribution to sea-level change from regions such as West Antarctica is dependent on a combination of remote sensing methods. A key method, the measurement of changes in Earth's gravity via the GRACE satellite mission, requires a potentially large correction to account for the isostatic response of the solid Earth to ice-load changes since the Last Glacial Maximum. In this study, we combine glacial isostatic adjustment modelling with a new GPS dataset of solid Earth deformation for the southern Antarctic Peninsula to test the current understanding of ice history in this region. A sufficiently complete history of past ice-load change is required for glacial isostatic adjustment models to accurately predict the spatial variation of ongoing solid Earth deformation, once the independently-constrained effects of present-day ice mass loss have been accounted for. Comparisons between the GPS data and glacial isostatic adjustment model predictions reveal a substantial misfit. The misfit is localized on the southwestern Weddell Sea, where current ice models under-predict uplift rates by approximately 2 mm yr−1. This under-prediction suggests that either the retreat of the ice sheet grounding line in this region occurred significantly later in the Holocene than currently assumed, or that the region previously hosted more ice than currently assumed. This finding demonstrates the need for further fieldwork to obtain direct constraints on the timing of Holocene grounding line retreat in the southwestern Weddell Sea and that GRACE estimates of ice sheet mass balance will be unreliable in this region until this is resolved.

AB - The measurement of ongoing ice-mass loss and associated melt water contribution to sea-level change from regions such as West Antarctica is dependent on a combination of remote sensing methods. A key method, the measurement of changes in Earth's gravity via the GRACE satellite mission, requires a potentially large correction to account for the isostatic response of the solid Earth to ice-load changes since the Last Glacial Maximum. In this study, we combine glacial isostatic adjustment modelling with a new GPS dataset of solid Earth deformation for the southern Antarctic Peninsula to test the current understanding of ice history in this region. A sufficiently complete history of past ice-load change is required for glacial isostatic adjustment models to accurately predict the spatial variation of ongoing solid Earth deformation, once the independently-constrained effects of present-day ice mass loss have been accounted for. Comparisons between the GPS data and glacial isostatic adjustment model predictions reveal a substantial misfit. The misfit is localized on the southwestern Weddell Sea, where current ice models under-predict uplift rates by approximately 2 mm yr−1. This under-prediction suggests that either the retreat of the ice sheet grounding line in this region occurred significantly later in the Holocene than currently assumed, or that the region previously hosted more ice than currently assumed. This finding demonstrates the need for further fieldwork to obtain direct constraints on the timing of Holocene grounding line retreat in the southwestern Weddell Sea and that GRACE estimates of ice sheet mass balance will be unreliable in this region until this is resolved.

KW - Sea level change

KW - Space geodetic surveys

KW - Global change from geodesy

KW - Glaciology

KW - Antarctica

U2 - 10.1093/gji/ggv327

DO - 10.1093/gji/ggv327

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EP - 754

JO - Geophysical Journal International

JF - Geophysical Journal International

SN - 0956-540X

IS - 1

ER -