Widespread seawater intrusions beneath the grounded ice of Thwaites Glacier, West Antarctica.
Warm water from the Southern Ocean has a dominant impact on the evolution of Antarctic glaciers and in turn on their contribution to sea level rise. Using a continuous time series of daily-repeat satellite synthetic-aperture radar interferometry data from the ICEYE constellation collected in March-J...
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ftcdlib:oai:escholarship.org:ark:/13030/qt9q4236kr 2024-06-23T07:45:54+00:00 Widespread seawater intrusions beneath the grounded ice of Thwaites Glacier, West Antarctica. Ciracì, Enrico Scheuchl, Bernd Tolpekin, Valentyn Wollersheim, Michael Dow, Christine Rignot, Eric 2024-05-28 application/pdf https://escholarship.org/uc/item/9q4236kr unknown eScholarship, University of California qt9q4236kr https://escholarship.org/uc/item/9q4236kr public Proceedings of the National Academy of Sciences, vol 121, iss 22 Antarctica Southern Ocean hydrology interferometry sea level rise article 2024 ftcdlib 2024-06-12T00:32:25Z Warm water from the Southern Ocean has a dominant impact on the evolution of Antarctic glaciers and in turn on their contribution to sea level rise. Using a continuous time series of daily-repeat satellite synthetic-aperture radar interferometry data from the ICEYE constellation collected in March-June 2023, we document an ice grounding zone, or region of tidally controlled migration of the transition boundary between grounded ice and ice afloat in the ocean, at the main trunk of Thwaites Glacier, West Antarctica, a strong contributor to sea level rise with an ice volume equivalent to a 0.6-m global sea level rise. The ice grounding zone is 6 km wide in the central part of Thwaites with shallow bed slopes, and 2 km wide along its flanks with steep basal slopes. We additionally detect irregular seawater intrusions, 5 to 10 cm in thickness, extending another 6 km upstream, at high tide, in a bed depression located beyond a bedrock ridge that impedes the glacier retreat. Seawater intrusions align well with regions predicted by the GlaDS subglacial water model to host a high-pressure distributed subglacial hydrology system in between lower-pressure subglacial channels. Pressurized seawater intrusions will induce vigorous melt of grounded ice over kilometers, making the glacier more vulnerable to ocean warming, and increasing the projections of ice mass loss. Kilometer-wide, widespread seawater intrusion beneath grounded ice may be the missing link between the rapid, past, and present changes in ice sheet mass and the slower changes replicated by ice sheet models. Article in Journal/Newspaper Antarc* Antarctic Antarctica Ice Sheet Southern Ocean Thwaites Glacier West Antarctica University of California: eScholarship Antarctic Southern Ocean Thwaites Glacier ENVELOPE(-106.750,-106.750,-75.500,-75.500) West Antarctica |
institution |
Open Polar |
collection |
University of California: eScholarship |
op_collection_id |
ftcdlib |
language |
unknown |
topic |
Antarctica Southern Ocean hydrology interferometry sea level rise |
spellingShingle |
Antarctica Southern Ocean hydrology interferometry sea level rise Ciracì, Enrico Scheuchl, Bernd Tolpekin, Valentyn Wollersheim, Michael Dow, Christine Rignot, Eric Widespread seawater intrusions beneath the grounded ice of Thwaites Glacier, West Antarctica. |
topic_facet |
Antarctica Southern Ocean hydrology interferometry sea level rise |
description |
Warm water from the Southern Ocean has a dominant impact on the evolution of Antarctic glaciers and in turn on their contribution to sea level rise. Using a continuous time series of daily-repeat satellite synthetic-aperture radar interferometry data from the ICEYE constellation collected in March-June 2023, we document an ice grounding zone, or region of tidally controlled migration of the transition boundary between grounded ice and ice afloat in the ocean, at the main trunk of Thwaites Glacier, West Antarctica, a strong contributor to sea level rise with an ice volume equivalent to a 0.6-m global sea level rise. The ice grounding zone is 6 km wide in the central part of Thwaites with shallow bed slopes, and 2 km wide along its flanks with steep basal slopes. We additionally detect irregular seawater intrusions, 5 to 10 cm in thickness, extending another 6 km upstream, at high tide, in a bed depression located beyond a bedrock ridge that impedes the glacier retreat. Seawater intrusions align well with regions predicted by the GlaDS subglacial water model to host a high-pressure distributed subglacial hydrology system in between lower-pressure subglacial channels. Pressurized seawater intrusions will induce vigorous melt of grounded ice over kilometers, making the glacier more vulnerable to ocean warming, and increasing the projections of ice mass loss. Kilometer-wide, widespread seawater intrusion beneath grounded ice may be the missing link between the rapid, past, and present changes in ice sheet mass and the slower changes replicated by ice sheet models. |
format |
Article in Journal/Newspaper |
author |
Ciracì, Enrico Scheuchl, Bernd Tolpekin, Valentyn Wollersheim, Michael Dow, Christine Rignot, Eric |
author_facet |
Ciracì, Enrico Scheuchl, Bernd Tolpekin, Valentyn Wollersheim, Michael Dow, Christine Rignot, Eric |
author_sort |
Ciracì, Enrico |
title |
Widespread seawater intrusions beneath the grounded ice of Thwaites Glacier, West Antarctica. |
title_short |
Widespread seawater intrusions beneath the grounded ice of Thwaites Glacier, West Antarctica. |
title_full |
Widespread seawater intrusions beneath the grounded ice of Thwaites Glacier, West Antarctica. |
title_fullStr |
Widespread seawater intrusions beneath the grounded ice of Thwaites Glacier, West Antarctica. |
title_full_unstemmed |
Widespread seawater intrusions beneath the grounded ice of Thwaites Glacier, West Antarctica. |
title_sort |
widespread seawater intrusions beneath the grounded ice of thwaites glacier, west antarctica. |
publisher |
eScholarship, University of California |
publishDate |
2024 |
url |
https://escholarship.org/uc/item/9q4236kr |
long_lat |
ENVELOPE(-106.750,-106.750,-75.500,-75.500) |
geographic |
Antarctic Southern Ocean Thwaites Glacier West Antarctica |
geographic_facet |
Antarctic Southern Ocean Thwaites Glacier West Antarctica |
genre |
Antarc* Antarctic Antarctica Ice Sheet Southern Ocean Thwaites Glacier West Antarctica |
genre_facet |
Antarc* Antarctic Antarctica Ice Sheet Southern Ocean Thwaites Glacier West Antarctica |
op_source |
Proceedings of the National Academy of Sciences, vol 121, iss 22 |
op_relation |
qt9q4236kr https://escholarship.org/uc/item/9q4236kr |
op_rights |
public |
_version_ |
1802642942222925824 |