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A recently digitized vintage film has doubled scientists' retreat in Antarctic ground ice history and revealed that an ice shelf on the Thwaites Glacier in West Antarctic is melting faster than it is thought before. This finding contributes to predictions of sea-level rise affecting coastal communities around the world.
A new study shows that Thwaites Glacier in Antarctica, shown here, is likely to melt further than expected inland. (Image credit: NASA)
The researchers drew their conclusions by comparing the Thwaites Glacier radar recordings with modern data entering the ice. The search appeared in Proceedings of the National Academy of Sciences September 2nd
"With this recording, we can now see the areas in which the pack ice is becoming thinner and could break through," said lead author Dustin Schroeder, assistant professor of geophysics at the Faculty of Earth Sciences, of the And the environment of Stanford University (Stanford Earth). ) who spearheaded efforts to digitize historical data from airborne surveys conducted in the 1970s. "It's a pretty hard place to reach and we're really lucky to fly over that pack ice."
The researchers digitized approximately 250,000 miles of Antarctic radar data flight originally captured on a 35mm optical film between 1971 and 1979 as part of a collaboration between Stanford and the Scott Polar Research Institute (SPRI ) from the University of Cambridge in the United Kingdom. These data have been published online. public archives through Stanford libraries, which has allowed other scientists to compare them to modern radar data to understand the long-term changes in ice thickness, glacier basic over 40 years.
Sea level forecasts
The information provided by the historical archives will help efforts like the Intergovernmental Panel on Climate Change (IPCC) in its objective of projecting climate and sea level rise for the next 100 years. By allowing 40 to 50 years to look back at subterranean conditions instead of the 10 to 20 years provided by modern data, scientists can better understand what has happened and make more accurate projections of what is happening. future, explained Schroeder.
"You can really see geometry over this long time, how these ocean currents melted the ice floe, not just in general, but exactly where and how," said Schroeder, also a faculty member at the Stanford Woods Institute. For the environment. "When we model ice cap behavior and sea level projections in the future, we need to understand the processes at the base of the icecap that have led to the changes we are seeing."
The film was originally recorded as part of an exploratory investigation using an ice-penetrating radar, a technique still used today to capture information from the surface across the bottom of the ice cap. . The radar shows mountains, volcanoes and lakes beneath the surface of the Antarctic, as well as layers inside the ice cap that reveal the history of climate and flows.
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