A high-resolution Antarctic grounding zone product from ICESat-2 laser altimetry

<p>The Antarctic grounding zone, which is the transition between the fully grounded ice sheet to freely floating ice shelf, plays a critical role in ice sheet stability, mass budget calculations, and ice sheet model projections. It is therefore important to continuously monitor its location an...

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Main Authors: T. Li, G. J. Dawson, S. J. Chuter, J. L. Bamber
Format: Article
Language:English
Published: Copernicus Publications 2022-02-01
Series:Earth System Science Data
Online Access:https://essd.copernicus.org/articles/14/535/2022/essd-14-535-2022.pdf
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author T. Li
G. J. Dawson
S. J. Chuter
J. L. Bamber
J. L. Bamber
author_facet T. Li
G. J. Dawson
S. J. Chuter
J. L. Bamber
J. L. Bamber
author_sort T. Li
collection DOAJ
description <p>The Antarctic grounding zone, which is the transition between the fully grounded ice sheet to freely floating ice shelf, plays a critical role in ice sheet stability, mass budget calculations, and ice sheet model projections. It is therefore important to continuously monitor its location and migration over time. Here we present the first ICESat-2-derived high-resolution grounding zone product of the Antarctic Ice Sheet, including three important boundaries: the inland limit of tidal flexure (Point F), inshore limit of hydrostatic equilibrium (Point H), and the break in slope (Point I<span class="inline-formula"><sub>b</sub></span>). This dataset was derived from automated techniques developed in this study, using ICESat-2 laser altimetry repeat tracks between 30 March 2019 and 30 September 2020. The new grounding zone product has a near-complete coverage of the Antarctic Ice Sheet with a total of 21 346 Point F, 18 149 Point H, and 36 765 Point I<span class="inline-formula"><sub>b</sub></span> locations identified, including the difficult-to-survey grounding zones, such as the fast-flowing glaciers draining into the Amundsen Sea embayment. The locations of newly derived ICESat-2 landward limit of tidal flexure agree well with the most recent differential synthetic aperture radar interferometry (DInSAR) observations in 2018, with a mean absolute separation and standard deviation of 0.02 and 0.02 km, respectively. By comparing the ICESat-2-derived grounding zone with the previous grounding zone products, we find a grounding line retreat of up to 15 km on the Crary Ice Rise of Ross Ice Shelf and a pervasive landward grounding line migration along the Amundsen Sea embayment during the past 2 decades. We also identify the presence of ice plains on the Filchner–Ronne Ice Shelf and the influence of oscillating ocean tides on grounding zone migration. The product derived from this study is available at <span class="uri">https://doi.org/10.5523/bris.bnqqyngt89eo26qk8keckglww</span> (Li et al., 2021) and is archived and maintained at the National Snow and Ice Data Center.</p>
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spelling doaj.art-660e9c55572d4f049a3ad59d9aea1d852022-12-22T00:04:41ZengCopernicus PublicationsEarth System Science Data1866-35081866-35162022-02-011453555710.5194/essd-14-535-2022A high-resolution Antarctic grounding zone product from ICESat-2 laser altimetryT. Li0G. J. Dawson1S. J. Chuter2J. L. Bamber3J. L. Bamber4Bristol Glaciology Centre, School of Geographical Sciences, University of Bristol, Bristol, BS8 1SS, UKBristol Glaciology Centre, School of Geographical Sciences, University of Bristol, Bristol, BS8 1SS, UKBristol Glaciology Centre, School of Geographical Sciences, University of Bristol, Bristol, BS8 1SS, UKBristol Glaciology Centre, School of Geographical Sciences, University of Bristol, Bristol, BS8 1SS, UKDepartment of Aerospace and Geodesy, Data Science in Earth Observation, Technical University of Munich, 85521 Ottobrunn, Germany<p>The Antarctic grounding zone, which is the transition between the fully grounded ice sheet to freely floating ice shelf, plays a critical role in ice sheet stability, mass budget calculations, and ice sheet model projections. It is therefore important to continuously monitor its location and migration over time. Here we present the first ICESat-2-derived high-resolution grounding zone product of the Antarctic Ice Sheet, including three important boundaries: the inland limit of tidal flexure (Point F), inshore limit of hydrostatic equilibrium (Point H), and the break in slope (Point I<span class="inline-formula"><sub>b</sub></span>). This dataset was derived from automated techniques developed in this study, using ICESat-2 laser altimetry repeat tracks between 30 March 2019 and 30 September 2020. The new grounding zone product has a near-complete coverage of the Antarctic Ice Sheet with a total of 21 346 Point F, 18 149 Point H, and 36 765 Point I<span class="inline-formula"><sub>b</sub></span> locations identified, including the difficult-to-survey grounding zones, such as the fast-flowing glaciers draining into the Amundsen Sea embayment. The locations of newly derived ICESat-2 landward limit of tidal flexure agree well with the most recent differential synthetic aperture radar interferometry (DInSAR) observations in 2018, with a mean absolute separation and standard deviation of 0.02 and 0.02 km, respectively. By comparing the ICESat-2-derived grounding zone with the previous grounding zone products, we find a grounding line retreat of up to 15 km on the Crary Ice Rise of Ross Ice Shelf and a pervasive landward grounding line migration along the Amundsen Sea embayment during the past 2 decades. We also identify the presence of ice plains on the Filchner–Ronne Ice Shelf and the influence of oscillating ocean tides on grounding zone migration. The product derived from this study is available at <span class="uri">https://doi.org/10.5523/bris.bnqqyngt89eo26qk8keckglww</span> (Li et al., 2021) and is archived and maintained at the National Snow and Ice Data Center.</p>https://essd.copernicus.org/articles/14/535/2022/essd-14-535-2022.pdf
spellingShingle T. Li
G. J. Dawson
S. J. Chuter
J. L. Bamber
J. L. Bamber
A high-resolution Antarctic grounding zone product from ICESat-2 laser altimetry
Earth System Science Data
title A high-resolution Antarctic grounding zone product from ICESat-2 laser altimetry
title_full A high-resolution Antarctic grounding zone product from ICESat-2 laser altimetry
title_fullStr A high-resolution Antarctic grounding zone product from ICESat-2 laser altimetry
title_full_unstemmed A high-resolution Antarctic grounding zone product from ICESat-2 laser altimetry
title_short A high-resolution Antarctic grounding zone product from ICESat-2 laser altimetry
title_sort high resolution antarctic grounding zone product from icesat 2 laser altimetry
url https://essd.copernicus.org/articles/14/535/2022/essd-14-535-2022.pdf
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