Melt at grounding line controls observed and future retreat of Smith, Pope, and Kohler glaciers
Item
Title (Dublin Core)
Melt at grounding line controls observed and future retreat of Smith, Pope, and Kohler glaciers
Description (Dublin Core)
<p>Smith, Pope, and Kohler glaciers and the corresponding Crosson and Dotson
ice shelves have undergone speedup, thinning, and rapid grounding-line
retreat in recent years, leaving them in a state likely conducive to future
retreat. We conducted a suite of numerical model simulations of these
glaciers and compared the results to observations to determine the processes
controlling their recent evolution. The model simulations indicate that the
state of these glaciers in the 1990s was not inherently unstable, i.e., that
small perturbations to the grounding line would not necessarily have caused
the large retreat that has been observed. Instead, sustained, elevated melt
at the grounding line was needed to cause the observed retreat. Weakening of
the margins of Crosson Ice Shelf may have hastened the onset of
grounding-line retreat but is unlikely to have initiated these rapid changes
without an accompanying increase in melt. In the simulations that most
closely match the observed thinning, speedup, and retreat, modeled
grounding-line retreat and ice loss continue unabated throughout the
21st century, and subsequent retreat along Smith Glacier's trough
appears likely. Given the rapid progression of grounding-line retreat in the
model simulations, thinning associated with the retreat of Smith Glacier may
reach the ice divide and undermine a portion of the Thwaites catchment as
quickly as changes initiated at the Thwaites terminus.</p>
ice shelves have undergone speedup, thinning, and rapid grounding-line
retreat in recent years, leaving them in a state likely conducive to future
retreat. We conducted a suite of numerical model simulations of these
glaciers and compared the results to observations to determine the processes
controlling their recent evolution. The model simulations indicate that the
state of these glaciers in the 1990s was not inherently unstable, i.e., that
small perturbations to the grounding line would not necessarily have caused
the large retreat that has been observed. Instead, sustained, elevated melt
at the grounding line was needed to cause the observed retreat. Weakening of
the margins of Crosson Ice Shelf may have hastened the onset of
grounding-line retreat but is unlikely to have initiated these rapid changes
without an accompanying increase in melt. In the simulations that most
closely match the observed thinning, speedup, and retreat, modeled
grounding-line retreat and ice loss continue unabated throughout the
21st century, and subsequent retreat along Smith Glacier's trough
appears likely. Given the rapid progression of grounding-line retreat in the
model simulations, thinning associated with the retreat of Smith Glacier may
reach the ice divide and undermine a portion of the Thwaites catchment as
quickly as changes initiated at the Thwaites terminus.</p>
Creator (Dublin Core)
D. A. Lilien
I. Joughin
B. Smith
N. Gourmelen
Subject (Dublin Core)
Environmental sciences
GE1-350
Geology
QE1-996.5
Publisher (Dublin Core)
Copernicus Publications
Date (Dublin Core)
2019-11-01T00:00:00Z
Type (Dublin Core)
article
Identifier (Dublin Core)
10.5194/tc-13-2817-2019
1994-0416
1994-0424
https://doaj.org/article/995a9688b6b84227900d520155dd10f8
Source (Dublin Core)
The Cryosphere, Vol 13, Pp 2817-2834 (2019)
Language (Dublin Core)
EN
Relation (Dublin Core)
https://www.the-cryosphere.net/13/2817/2019/tc-13-2817-2019.pdf
https://doaj.org/toc/1994-0416
https://doaj.org/toc/1994-0424
Provenance (Dublin Core)
Journal Licence: CC BY