Rapidly Melting Patagonian Glaciers Are Alarming for This Reason
Billions of tons of water are pouring into oceans.
by Danny PaezPatagonia, the southernmost tip of South America, is home to some of the world’s most unkempt natural beauty. Barren desserts, craggy mountains, and some of the world’s largest glaciers outside of Antarctica can all be found within this geographic wonderland. But an alarming discovery by the European Space Agency revealed how shifting climate conditions and geological features may change this region’s massive sheets of ice forever.
A team of ESA scientists used the polar-ice monitoring satellite, CryoSat to determine that some of Patagonia’s glaciers are melting away faster than any of the other glaciers in the world. In a paper published in the journal Remote Sensing of Environment, the researchers describe how they used their eye in the sky to detect complex patterns in the changing height of the ice. They then used this data to create a map depicting the rate at which it is melting.
The technique of swath processing differs from conventional radar altimetry. Using CryoSat’s novel interferometric mode, whole swaths, rather than single points, of elevations can be computed. This is yielding more detail that ever before on how glacial ice is changing.
“Using CryoSat’s novel interferometric mode, we see how the radar wavefront interacts with the surface,” says Noel Gourmelen from the University of Edinburgh in a statement. “We can then extract a whole swath of elevations rather than single elevation points. This is revolutionizing the use of CryoSat over complex icy terrains, yielding more detail than we ever thought possible.”
Data from the orbiter showed that between the years 2011 and 2017 there was widespread thinning of ice, especially in Patagonia’s northernmost ice fields. Over the six years, Patagonian glaciers receded at a rate of 21 gigatons — 21 billion tons — per year.
These figures might be difficult to picture, so consider that an average whale shark weighs 20.6 metric tons, according to National Geographic. This would mean that every year these glaciers shed off roughly a billion whale sarks worth of ice, which is the equivalent of adding 0.06 millimeters (or 2.4 thousandths of an inch) to global sea level. This flow of ice water coupled with the melting glaciers in Antarctica and Greenland can lead to drastic changes to coastal communities.
ESA’s Earth Explorer CryoSat mission is dedicated to precise monitoring of changes in the thickness of marine ice floating in the polar oceans and variations in the thickness of the vast ice sheets that blanket Greenland and Antarctica.
Aside from climate warming, many of Patagonia’s glaciers are adjacent to fjords and lakes, which can further worsen surface melting. A 2015 study from the University of California, Irving showed that ocean water surrounding these geological formations can badly undercut ice sheets.
With this study under their belts, the ESA group wants to continue using CryoSat to monitor and map as many of the world’s 200,000 glaciers as possible. Providing more accurate data on how quickly ice sheets are melting can inspire action to mitigate the detrimental effects of climate change and change the course we’re on.
