Glaciers in the Antarctic Peninsula, as seen from afar. Professor Anna E. Hogg, University of Leeds
Researchers claim that melting snow and warmer ocean temperatures make glaciers – massive moving ice sheets – move faster during the summer.
A new study has shown that the ice flow speeds up by up to 22% in summer when temperatures are cooler. This gives an insight into the ways climate change might influence glaciers' behavior and the role they may play in raising sea levels.
The study of the rugged Antarctic peninsula has been limited until now due to difficulties in getting onto the glaciers to perform fieldwork. However, advances in satellite technology have given us insight into the speed at which the glaciers are moving and leaking water into the surrounding ocean.
Glaciers in the Antarctic Peninsula, captured by aerial photography. University of Leeds, Dr. Anna E. Hogg
The Antarctic Peninsula is the largest reservoir of frozen water on Earth. Between 1992 and 2017, meltwater from the glaciers has increased global sea levels by about 7.6 mm, one of the major uncertainties in forecasting climate change.
More than 10,000 satellite photographs taken above the Antarctic Peninsula between 2014 and 2021 have been used by a team of researchers led by scientists at the University of Leeds to understand how the flow of glaciers into the Antarctic suburbs changes during colder and warmer seasons.
"One of the main findings of this study is that it demonstrates how sensitive glaciers in Antarctica are to the environment."
The research will be published today (February 27, 2023) in the journal Nature Geosciences.
Ben Wallis, University of Leeds/ESA Animation shows the flow of Breguet Glacier, one of the 105 glaciers included in the research. The same techniques are used to measure how fast the ice is moving.
The Antarctic Peninsula is Antarctica's most northern and warmest region. Its 1,000 km long mountainous spine is comparable to that of Great Britain's east coast, and is home to a diverse marine ecosystem of seals, penguins, and whales.
Glaciers drain ice from the ice sheet directly into the Southern Ocean on the peninsula's west coast.
The speed-up in the glacier occurred in summer as snow melts and the temperature of the waters in the Southern Ocean rose. Water from the melting snow acts as a lubricant between the ice sheet and the underlying rock, reducing friction and increasing the speed at which the glaciers slide.
The warmer waters of the Southern Ocean erode the moving ice front, which reduces the buttressing forces it exerts to resist the ice flow.
"The Antarctic Peninsula has experienced some of the most rapid warming of any area on Earth," says Dr. Anna Hogg, an associate professor at the Leeds Institute for Climate and Atmospheric Science. Continuous research like this will help glaciologists monitor how quickly change is happening, thus enabling accurate predictions about how Earth's ice will respond to climate change.
Copernicus, International Bathymetric Chart of the Southern Ocean (IBCSO), Reference Elevation Model of Antarctica (REMA), British Antarctic Survey (BAS), Ben Wallis, University of Leeds
The Copernicus Sentinel-1 satellite, which was used in this investigation, is monitored every week along Antarctica's entire coastline.
The satellite is equipped with a synthetic aperture radar that can "see" through clouds, allowing for day and night observations of the glaciers.
"This study highlights how high-resolution satellite imagery can help us monitor how the environment in remote areas is changing." Future satellites, such as the Copernicus Sentinel expansion families, promise to provide enhanced continuity and capabilities that will provide further insight into the factors and processes that drive ice mass balance and sea level rise.
Reference: "West Antarctic Peninsula glaciers' seasonal speed-up from 2014 to 2021," 27 February 2023, Nature Geoscience. DOI: 10.1038/s41561-023-01131-4
Ben Wallis, Anna Hogg, and Ben Davison, all from the University of Leeds, have contributed to the study, which is based at the Institute for Marine and Atmospheric Research in Utrecht. Jan Melchior van Wessem and Michiel van den Broeke, both from the Institute for Marine and Atmospheric Research.
Natural Environment Research Council, European Space Agency, Nederlandse Organisatie voor Wetenschappelijk Onderzoek, and the Netherlands Earth System Science Centre are among those providing funding.