Glacier change along West Antarctica's Marie Byrd Land Sector and links to inter-decadal atmosphere–ocean variability
<p>Over the past 20 years satellite remote sensing has captured significant downwasting of glaciers that drain the West Antarctic Ice Sheet into the ocean, particularly across the Amundsen Sea Sector. Along the neighbouring Marie Byrd Land Sector, situated west of Thwaites Glacier to Ross I...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2018-07-01
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| Series: | The Cryosphere |
| Online Access: | https://www.the-cryosphere.net/12/2461/2018/tc-12-2461-2018.pdf |
| Summary: | <p>Over the past 20 years satellite remote sensing has captured significant
downwasting of glaciers that drain the West Antarctic Ice Sheet into the
ocean, particularly across the Amundsen Sea Sector. Along the neighbouring
Marie Byrd Land Sector, situated west of Thwaites Glacier to Ross Ice Shelf,
glaciological change has been only sparsely monitored. Here, we use optical
satellite imagery to track grounding-line migration along the Marie Byrd Land
Sector between 2003 and 2015, and compare observed changes with ICESat and
CryoSat-2-derived surface elevation and thickness change records. During the
observational period, 33 % of the grounding line underwent retreat, with
no significant advance recorded over the remainder of the ∼  2200 km
long coastline. The greatest retreat rates were observed along the
650 km-long Getz Ice Shelf, further west of which only minor retreat
occurred. The relative glaciological stability west of
Getz Ice Shelf can be
attributed to a divergence of the Antarctic Circumpolar Current from the
continental-shelf break at 135° W, coincident with a transition in
the morphology of the continental shelf. Along Getz Ice Shelf, grounding-line
retreat reduced by 68 % during the CryoSat-2 era relative to earlier
observations. Climate reanalysis data imply that wind-driven upwelling of
Circumpolar Deep Water would have been reduced during this later period,
suggesting that the observed slowdown was a response to reduced oceanic
forcing. However, lack of comprehensive oceanographic and bathymetric
information proximal to Getz Ice Shelf's grounding zone make it difficult to
assess the role of intrinsic glacier dynamics, or more complex
ice-sheet–ocean interactions, in moderating this slowdown. Collectively, our
findings underscore the importance of spatial and inter-decadal variability
in atmosphere and ocean interactions in moderating glaciological change
around Antarctica.</p> |
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| ISSN: | 1994-0416 1994-0424 |