Using a 25-year record of satellite observations over the Getz region in West Antarctica, scientists have found that the speed at which glaciers are moving towards the ocean increases dramatically. This new study, which includes data from the Copernicus Sentinel-1 mission and ESA’s CryoSat missions, will help determine if these glaciers could collapse in the next few decades and how this will affect future sea level rise in the world.
Ice lost in Antarctica often makes headlines, but this is the first time scientists have deeply studied a particular area. A new study by researchers from the University of Leeds shows that between 1994 and 2018, all 14 glaciers in Goetz accelerated by an average of almost 25%, and three glaciers by more than 44%.
The results of the study show that the glaciers lost a total of 315 gigatons of ice, which raised the global average sea level by 0.9 mm, which is equivalent to 126 million Olympic swimming pools.
The Getz area in Antarctica is so remote that humans have never set foot on much of it. But satellites show a high rate of increase in glacier speed, coupled with thinning ice, now confirm that the Getz Basin is in dynamic imbalance, which means it is losing more ice than it receives from snowfall.
The scientists used two different types of satellite measurements. Radar data from the Copernicus Sentinel-1 mission, legacy data from the ERS mission from ESA’s Climate Change Initiative, and NASA data from MEaSUREs allowed them to calculate how fast glaciers moved over a 25-year study period. To measure how much the ice is thinning, they used altimetry data from ESA’s ERS, Envisat and CryoSat missions through the IMBIE assessment.
“Using a combination of observation and simulation, we show highly directional acceleration models. For example, we are seeing the biggest changes in the central region of Getz, where one glacier flows 391 meters per year faster in 2018 than in 1994. This is a significant change, as the current flow rate is 669 meters per year, which is 59% more than in just two and a half decades. “Heather Selly, Glaciologist at the Center for Polar Observation and Modeling, University of Leeds
The widely reported thinning and acceleration seen in the neighboring Amundsen Sea glaciers now extends 1,000 km along the West Antarctic coast to Getz. The glacier acceleration model shows a highly localized response to ocean dynamics.
But scientists need consistent and extensive samples of both ice velocity and ocean temperature to better understand dynamic ice loss, which currently accounts for 98.8% of Antarctica’s contribution to sea level rise. By studying 25-year measurements of the ocean, the research team was able to show complex annual variations in ocean temperature. These results suggest that the warming of ocean waters is largely responsible for this dynamic imbalance.
“Without satellites, we know very little about the distant polar regions, so it is very important that we continue to plan missions for the future. For example, the upcoming Biomass Earth Explorer satellite will be able to measure with an entirely new instrument that works in the P-band to penetrate deep into ice. Other missions related to the polar regions include the Copernicus Expansion missions: CRISTAL, which will carry a dual-band altimeter, and ROSE-L, which will carry L-band synthetic aperture radar. “Markus Engdahl, European Space Agency
These activities contribute to the efforts of the ESA Polar Science Cluster to develop our ability to observe, understand and predict dramatic changes affecting the polar regions and subsequent impacts around the world.