After conducting a comprehensive, seven-year survey of Patagonia, glaciologists from the University of California, Irvine and partner institutions in Argentina and Chile have concluded that the ice sheets in this vast region of South America are considerably more massive than expected.
Through a combination of ground observations and airborne gravity and radar sounding methods, the scientists created the most complete ice density map of the area to date and found that some glaciers are as much as a mile (1,600 meters) thick. Their findings were published today in the American Geophysical Union journal Geophysical Research Letters.
“We did not think the ice fields on the Patagonian plateau could be quite that substantial,” said co-author Eric Rignot, Donald Bren Professor and chair of Earth system science at UCI. “As a result of this multinational research project, we found that – added together – the northern and southern portions of Patagonia clearly hold more ice than anticipated, roughly 40 times the ice volume of the European Alps.”
Patagonia is home to the largest ice fields in the Southern Hemisphere outside Antarctica, and its glaciers are among the fastest-moving in the world. Surface elevation observations from satellite radar altimetry and optical imagery have shown that most of the ice slabs in the region have been thinning rapidly over the past four decades. The contribution to global sea level rise from their melting has increased at an accelerating pace during that time.
Study co-author M. Gabriela Lenzano, a researcher with Argentina’s National Scientific and Technical Research Council, said the results will “help the scientific community better explain the interactions and consequences of ice sheet dynamics and climate on this cold environment – and the impact on communities and ecosystems downstream.”
With more precise knowledge of the size and shape of the glaciers in this highly protected region – much of which is contained in one of the world’s largest national park systems – researchers and planners will be able to more accurately model the effects of global warming and plan for potential disruptions in freshwater resources that serve its inhabitants.
“This is why having accurate maps of the ice thickness is a priority,” said lead author Romain Millan, who was a UCI graduate student in Earth system science for the bulk of this research project and is now a postdoctoral scholar at the Institute of Environmental Geosciences in Grenoble, France. “It is fundamental to get the right contours and depth of the glacial valleys; otherwise, simulations of glacier retreat will always be wrong.”