Rapid bedrock uplift in the Antarctic Peninsula explained by viscoelastic response to recent ice unloading

Grace A. Nield, Valentina Roberta Barletta, Andrea Bordoni, Matt A. King, Pippa L. Whitehouse, Peter J. Clarke, Eugene Domack, Ted A. Scambos, Etienne Berthier

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Abstract

Since 1995 several ice shelves in the Northern Antarctic Peninsula have collapsed and triggered ice-mass unloading, invoking a solid Earth response that has been recorded at continuous GPS (cGPS) stations. A previous attempt to model the observation of rapid uplift following the 2002 breakup of Larsen B Ice Shelf was limited by incomplete knowledge of the pattern of ice unloading and possibly the assumption of an elastic-only mechanism. We make use of a new high resolution dataset of ice elevation change that captures ice-mass loss north of 66°S to first show that non-linear uplift of the Palmer cGPS station since 2002 cannot be explained by elastic deformation alone. We apply a viscoelastic model with linear Maxwell rheology to predict uplift since 1995 and test the fit to the Palmer cGPS time series, finding a well constrained upper mantle viscosity but less sensitivity to lithospheric thickness. We further constrain the best fitting Earth model by including six cGPS stations deployed after 2009 (the LARISSA network), with vertical velocities in the range 1.7 to 14.9 mm/yr. This results in a best fitting Earth model with lithospheric thickness of 100–140 km and upper mantle viscosity of 6×1017–2×1018 Pas – much lower than previously suggested for this region. Combining the LARISSA time series with the Palmer cGPS time series offers a rare opportunity to study the time-evolution of the low-viscosity solid Earth response to a well-captured ice unloading event.
Original languageEnglish
JournalEarth and Planetary Science Letters
Volume397
Pages (from-to)32-41
ISSN0012-821X
DOIs
Publication statusPublished - 2014

Keywords

  • Antarctic Peninsula
  • Larsen B
  • ice-mass loss
  • viscoelastic uplift
  • GPS
  • upper mantle viscosity

Cite this

Nield, Grace A. ; Barletta, Valentina Roberta ; Bordoni, Andrea ; King, Matt A. ; Whitehouse, Pippa L. ; Clarke, Peter J. ; Domack, Eugene ; Scambos, Ted A. ; Berthier, Etienne. / Rapid bedrock uplift in the Antarctic Peninsula explained by viscoelastic response to recent ice unloading. In: Earth and Planetary Science Letters. 2014 ; Vol. 397. pp. 32-41.
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title = "Rapid bedrock uplift in the Antarctic Peninsula explained by viscoelastic response to recent ice unloading",
abstract = "Since 1995 several ice shelves in the Northern Antarctic Peninsula have collapsed and triggered ice-mass unloading, invoking a solid Earth response that has been recorded at continuous GPS (cGPS) stations. A previous attempt to model the observation of rapid uplift following the 2002 breakup of Larsen B Ice Shelf was limited by incomplete knowledge of the pattern of ice unloading and possibly the assumption of an elastic-only mechanism. We make use of a new high resolution dataset of ice elevation change that captures ice-mass loss north of 66°S to first show that non-linear uplift of the Palmer cGPS station since 2002 cannot be explained by elastic deformation alone. We apply a viscoelastic model with linear Maxwell rheology to predict uplift since 1995 and test the fit to the Palmer cGPS time series, finding a well constrained upper mantle viscosity but less sensitivity to lithospheric thickness. We further constrain the best fitting Earth model by including six cGPS stations deployed after 2009 (the LARISSA network), with vertical velocities in the range 1.7 to 14.9 mm/yr. This results in a best fitting Earth model with lithospheric thickness of 100–140 km and upper mantle viscosity of 6×1017–2×1018 Pas – much lower than previously suggested for this region. Combining the LARISSA time series with the Palmer cGPS time series offers a rare opportunity to study the time-evolution of the low-viscosity solid Earth response to a well-captured ice unloading event.",
keywords = "Antarctic Peninsula, Larsen B, ice-mass loss, viscoelastic uplift, GPS, upper mantle viscosity",
author = "Nield, {Grace A.} and Barletta, {Valentina Roberta} and Andrea Bordoni and King, {Matt A.} and Whitehouse, {Pippa L.} and Clarke, {Peter J.} and Eugene Domack and Scambos, {Ted A.} and Etienne Berthier",
year = "2014",
doi = "10.1016/j.epsl.2014.04.019",
language = "English",
volume = "397",
pages = "32--41",
journal = "Earth and Planetary Science Letters",
issn = "0012-821X",
publisher = "Elsevier",

}

Rapid bedrock uplift in the Antarctic Peninsula explained by viscoelastic response to recent ice unloading. / Nield, Grace A.; Barletta, Valentina Roberta; Bordoni, Andrea; King, Matt A.; Whitehouse, Pippa L.; Clarke, Peter J.; Domack, Eugene; Scambos, Ted A.; Berthier, Etienne.

In: Earth and Planetary Science Letters, Vol. 397, 2014, p. 32-41.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - Rapid bedrock uplift in the Antarctic Peninsula explained by viscoelastic response to recent ice unloading

AU - Nield, Grace A.

AU - Barletta, Valentina Roberta

AU - Bordoni, Andrea

AU - King, Matt A.

AU - Whitehouse, Pippa L.

AU - Clarke, Peter J.

AU - Domack, Eugene

AU - Scambos, Ted A.

AU - Berthier, Etienne

PY - 2014

Y1 - 2014

N2 - Since 1995 several ice shelves in the Northern Antarctic Peninsula have collapsed and triggered ice-mass unloading, invoking a solid Earth response that has been recorded at continuous GPS (cGPS) stations. A previous attempt to model the observation of rapid uplift following the 2002 breakup of Larsen B Ice Shelf was limited by incomplete knowledge of the pattern of ice unloading and possibly the assumption of an elastic-only mechanism. We make use of a new high resolution dataset of ice elevation change that captures ice-mass loss north of 66°S to first show that non-linear uplift of the Palmer cGPS station since 2002 cannot be explained by elastic deformation alone. We apply a viscoelastic model with linear Maxwell rheology to predict uplift since 1995 and test the fit to the Palmer cGPS time series, finding a well constrained upper mantle viscosity but less sensitivity to lithospheric thickness. We further constrain the best fitting Earth model by including six cGPS stations deployed after 2009 (the LARISSA network), with vertical velocities in the range 1.7 to 14.9 mm/yr. This results in a best fitting Earth model with lithospheric thickness of 100–140 km and upper mantle viscosity of 6×1017–2×1018 Pas – much lower than previously suggested for this region. Combining the LARISSA time series with the Palmer cGPS time series offers a rare opportunity to study the time-evolution of the low-viscosity solid Earth response to a well-captured ice unloading event.

AB - Since 1995 several ice shelves in the Northern Antarctic Peninsula have collapsed and triggered ice-mass unloading, invoking a solid Earth response that has been recorded at continuous GPS (cGPS) stations. A previous attempt to model the observation of rapid uplift following the 2002 breakup of Larsen B Ice Shelf was limited by incomplete knowledge of the pattern of ice unloading and possibly the assumption of an elastic-only mechanism. We make use of a new high resolution dataset of ice elevation change that captures ice-mass loss north of 66°S to first show that non-linear uplift of the Palmer cGPS station since 2002 cannot be explained by elastic deformation alone. We apply a viscoelastic model with linear Maxwell rheology to predict uplift since 1995 and test the fit to the Palmer cGPS time series, finding a well constrained upper mantle viscosity but less sensitivity to lithospheric thickness. We further constrain the best fitting Earth model by including six cGPS stations deployed after 2009 (the LARISSA network), with vertical velocities in the range 1.7 to 14.9 mm/yr. This results in a best fitting Earth model with lithospheric thickness of 100–140 km and upper mantle viscosity of 6×1017–2×1018 Pas – much lower than previously suggested for this region. Combining the LARISSA time series with the Palmer cGPS time series offers a rare opportunity to study the time-evolution of the low-viscosity solid Earth response to a well-captured ice unloading event.

KW - Antarctic Peninsula

KW - Larsen B

KW - ice-mass loss

KW - viscoelastic uplift

KW - GPS

KW - upper mantle viscosity

U2 - 10.1016/j.epsl.2014.04.019

DO - 10.1016/j.epsl.2014.04.019

M3 - Journal article

VL - 397

SP - 32

EP - 41

JO - Earth and Planetary Science Letters

JF - Earth and Planetary Science Letters

SN - 0012-821X

ER -