Biological and Environmental Research - Earth and Environmental System Sciences
Earth and Environmental System Modeling

Rapid Viscoelastic Deformation Slows Marine Ice Sheet Instability at Pine Island Glacier

TitleRapid Viscoelastic Deformation Slows Marine Ice Sheet Instability at Pine Island Glacier
Publication TypeJournal Article
Year of Publication2020
JournalGeophysical Research Letters
Volume47
Number10
Abstract / 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 (∼1018 Pa s) than the Earth's average mantle (∼1021 Pa s). Here 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.

URLhttps://doi.org/10.1029/2019GL086446
DOI10.1029/2019GL086446
Journal: Geophysical Research Letters
Year of Publication: 2020
Volume: 47
Number: 10
Publication Date: 05/2020

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 (∼1018 Pa s) than the Earth's average mantle (∼1021 Pa s). Here 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.

DOI: 10.1029/2019GL086446
Citation:
Kachuck, SB, DF Martin, JN Bassis, and SF Price.  2020.  "Rapid Viscoelastic Deformation Slows Marine Ice Sheet Instability at Pine Island Glacier."  Geophysical Research Letters 47(10).  https://doi.org/10.1029/2019GL086446.