Rapid Viscoelastic Deformation Slows Marine Ice Sheet Instability at Pine Island Glacier
The ice sheets of the Amundsen Sea Embayment (ASE) are vulnerable to the marine ice sheet instability (MISI), which could cause irreversible collapse and raise sea levels by over a meter. The uncertain timing and scale of this collapse depend on the complex interaction between ice, ocean, and bedroc...
| Published in: | Geophysical Research Letters |
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| Main Authors: | , , , |
| Language: | unknown |
| Published: |
2021
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| Subjects: | |
| Online Access: | http://www.osti.gov/servlets/purl/1635191 https://www.osti.gov/biblio/1635191 https://doi.org/10.1029/2019gl086446 |
| Summary: | The ice sheets of the Amundsen Sea Embayment (ASE) are vulnerable to the marine ice sheet instability (MISI), which could cause irreversible collapse and raise sea levels by over a meter. The uncertain timing and scale of this collapse depend on the complex interaction between ice, ocean, and bedrock dynamics. The mantle beneath the ASE is likely less viscous (~10 18 Pa s) than the Earth's average mantle (~10 21 Pa s). In this paper we show that an effective equilibrium between Pine Island Glacier's retreat and the response of a weak viscoelastic mantle can reduce ice mass lost by almost 30% over 150 years. Other components of solid Earth response—purely elastic deformations and geoid perturbations—provide less stability than the viscoelastic response alone. Uncertainties in mantle rheology, topography, and basal melt affect how much stability we expect, if any. Our study indicates the importance of considering viscoelastic uplift during the rapid retreat associated with MISI. |
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