A new study reveals that a groundwater system, found in sediments deep in West Antarctica, likely in the form of a wet sponge, is revealing an unexplored part of the region and could have implications for how the frozen continent reacts to the climate crisis.
“People have assumed there may be deep groundwater in these sediments, but so far no one has done any detailed images,” said lead study author Chloe Gustafson, a postdoctoral researcher at the Scripps Institute at UCLA. Oceanography, in a press release.
Antarctica has 57 meters (187 feet) of sea-level rise potential, so we want to make sure we incorporate all the processes that control how ice flows from the continent into the oceans. Ice Flow Models,” added via email.
The ice sheet covering Antarctica is not completely solid. In recent years, researchers in Antarctica have discovered hundreds of interconnected liquid lakes and rivers contained within the ice itself. But this is the first time that large amounts of liquid water have been found in sediments under the ice.
The authors of this study, which was published in Science on Thursday, focused on a width of 60 miles (96.6 kilometers wide) Whillans Ice Stream, one of six streams feeding the Ross Ice Shelf, the largest in the world, the size of the Canadian Yukon Territory.
Gustafson and his colleagues spent six weeks in 2018 mapping the sediments under the ice. The research team used geophysical instruments placed directly on the surface to implement a technique called magnetic imaging.
This technology can detect the different degrees of electromagnetic energy generated by ice, sediment, rocky freshwater, and saltwater and create a map from these different information sources.
“We shot from the ice sheet about five kilometers (3.1 miles) away. Co-author Kerry Kee, associate professor of Earth and Environmental Sciences at Columbia University, said in a separate statement.
The researchers calculated that if they could extract groundwater from the sediments in the 100 square kilometers they drew on the surface, it would be a lake with a depth of 220 to 820 meters.
“The Empire State Building to the antenna is approximately 420 meters (1378 feet) high,” Gustafson, who conducted the research as a graduate student at Columbia University’s Lamont-Doherty Earth Observatory, said in the statement.
“At the shallow end, our waters will rise halfway over the Empire State Building. In the deepest part, there are approximately two Empire State Buildings stacked on top of each other. This is significant because subglacial lakes in this area range from 2 to 15 meters (6.6 to 49 metres). ft.). This is like one to four stories of the Empire State Building.”
how do we get there?
The maps revealed that the water became more saline with depth as a result of the formation of the groundwater system.
Ocean waters likely reached the area during a warm period 5,000 to 7,000 years ago, saturating the sediments with salty seawater. As the ice progressed, freshwater melting from pressure from the top and friction at the base of the ice was pushed into the upper sediments. Key said it may continue to percolate and mix with groundwater today.
The researchers said there is more work to be done to understand the implications of the groundwater discovery, particularly in relation to the climate crisis and rising sea levels.
The slow draining of water from the ice into the sediment would have prevented water from accumulating at the base of the ice – preventing the ice from moving into the sea.
However, if the surface ice layer is thin, the pressure drop can allow these deeper waters to rise. This upward movement will soften the base of the ice and speed up its flow.
Winnie Chou, assistant professor at Georgia Institute of Technology, wrote in a commentary on the research, published in the journal Science. She did not participate in the study.
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