Antarctic Peninsula: Satellites capture accelerating glacier movements

The Antarctic Peninsula, the northern and warmest region of Antarctica, is the largest frozen water reservoir on Earth. Around its coastlines, it is estimated that glaciers—massive blocks of moving ice—travel at an average speed of about one kilometer every year. 

Still, it has been difficult for researchers to acquire a more detailed insight into how this speed varies seasonally due to difficulties getting onto the glaciers to conduct fieldwork.

Additionally, glacier meltwater is estimated to have boosted global sea levels by 7.6 mm between 1992 and 2017. One of the main unknowns in modeling climate change is how that might evolve in the future.

Now, from space, a study published in Nature Geoscience on February 27 has tapped into the data of more than 10,000 high-resolution satellite images taken over seven years. The findings revealed a Greenland-like seasonal variation in the ice flow speed, which increased by up to 22 percent in summer when temperatures were warmer.

Observing the Antarctic Peninsula from space

"The Antarctic Peninsula has seen some of the most rapid warmings of any region on Earth. Continuing work like this will help glaciologists monitor how quickly change is occurring, enabling accurate assessments of how Earth's ice will respond to climate change," said lead author Dr. Anna Hogg in a press release, an Associate Professor at the Institute for Climate and Atmospheric Science at Leeds. 

The entire Antarctica coastline is monitored once a week by the Copernicus Sentinel-1 satellite, which the European Space Agency and European Commission operate. As the satellite has synthetic aperture radar, which can "see" through clouds, glacier measurements can be conducted both day and night.

Glaciers on the peninsula's western coast drain ice from the ice sheet into the Southern Ocean. According to the analysis of the satellite data from 2014 to 2021, the glacier speed-up occurs in the summer when the snow melts and the temperature of the Southern Ocean rises.

The water created by snowmelt is believed to work as a lubricant between the ice sheet and the rock beneath. As a result, there is less friction, and the glaciers slide more quickly.

In addition, the warmer waters of the Southern Ocean erode the front of the moving ice, which reduces the buttressing forces it exerts to resist the ice flow. 

"This study highlights how high-resolution satellite images can help us monitor how the environment is changing in remote regions," said Craig Donlon of the European Space Agency.

"Future satellites, such as the family of Copernicus Sentinel expansion missions, promise to bring enhanced continuity and capabilities that will spearhead further insight into the characteristics and processes governing ice mass balance and sea-level rise."

The complete study was published in Nature Geoscience and can be found here.