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...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2022-02-01
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| Series: | Earth System Science Data |
| Online Access: | https://essd.copernicus.org/articles/14/535/2022/essd-14-535-2022.pdf |
| Summary: | <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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| ISSN: | 1866-3508 1866-3516 |