Using a twenty-five-year record of satellite observations of the Getz region in western Antarctica, scientists have discovered that the pace at which glaciers are flowing toward the ocean is accelerating. This new research, which includes data from the Copernicus Sentinel-1 mission and ESA’s CryoSat mission, will help determine if these glaciers could collapse in the next few decades and how this will affect future global sea level rise.
Ice lost from Antarctica often makes headlines, but this is the first time that scientists have studied this area in detail.
Led by scientists from the University of Leeds in the UK, new research shows that between 1994 and 2018, all 14 glaciers in the Getz accelerated, on average, almost 25%, and three glaciers accelerated by over 44%.
The results published today in Nature Communications, also reported that glaciers lost a total of 315 gigatons of ice, adding 0.9 mm to the global mean sea level – the equivalent of 126 million Olympic pools.
Heather Selley, lead author of the study and a glaciologist at the Center for Polar Observation and Modeling at the University of Leeds, said: “The Getz region of Antarctica is so far away that people have never set foot on most of it.
“However, satellites can tell us what’s going on and the high rates of increased glacier speed, along with ice thinning, now confirm that the Getz basin is in ‘dynamic imbalance,’ meaning it is losing more ice than it gains through snowfall.”
The scientists used two different types of satellite measurements.
Radar data from the Copernicus Sentinel-1 mission, inherited data from the ERS mission through ESA’s climate change initiative, and NASA’s MEaSURE data allow them to calculate glacier movement speeds over a 25-year study period.
To measure how much ice was thinning, they used altimetric data from ESA’s ERS, Envisat and CryoSat missions via IMBIE assessment.
“By combining observations and modeling, we show highly localized acceleration patterns. For example, we observe the largest change in the central Getz area, with one glacier running 391 meters faster in 2018 than in 1994. This is a significant change because it now flows at a speed of 669 meters per year, an increase of 59% in just two and a half decades, ”Heather continued.
The research, funded by the Environmental Research Council and ESA’s Science for Society program, reports that the general thinning and acceleration observed on neighboring glaciers of the Amundsen Sea now extends over 1,000km along the coast of West Antarctica to the Getz.
Anna Hogg, co-author of the study, said: “The pattern of glacier acceleration shows a highly localized response to ocean dynamics.
“High-resolution satellite observations from satellites such as Sentinel-1, which collects a repeated image every six days, mean we can measure localized speed changes with increasing detail.
“Consistent and extensive sampling of ice speed and ocean temperature is needed to further understand dynamic ice loss, which now accounts for 98.8% of Antarctica’s contribution to sea level rise.”
By examining 25 years of ocean measurements, the research team was able to show complex and annual differences in ocean temperatures. These results suggest that ocean water warming is largely to blame for this dynamic imbalance.
ESC’s Marcus Engdahl added: “Without satellites, we know very little about remote polar regions, so it is vital that we continue to plan missions for the future. For example, the upcoming Biomass Earth Explorer satellite will be able to make measurements with a completely new instrument operating in P-belt for deep penetration into ice. Other missions relevant to the polar regions include the Copernicus Expansion CRISTAL missions, which will have a two-band altimeter, and the ROSE-L, which will carry an L-band radar with a synthetic aperture. “
This activity contributes to the efforts of the ESA Polar Science Cluster to improve our ability to observe, understand and predict dramatic changes affecting the polar regions and consequent impacts worldwide.
Picture: Laguna San Rafael National Park, Chile
Heather L. Selley et al. Widespread increase in dynamic imbalance in the Getz region of Antarctica from 1994 to 2018, Nature Communications (2021). DOI: 10.1038 / s41467-021-21321-1
Provided by the European Space Agency
Citation: Getz Glaciers on the Run (2021, February 23) retrieved February 23, 2021 from https://phys.org/news/2021-02-getz-glaciers.html
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