(CNN) – Scientists, hiding in the depths of the ice sheet covering Antarctica, discovered a huge amount of water.
The groundwater system is found in deep sediments in West Antarctica and is likely to have a spongy, moist texture. The system is revealing an unknown part of the region and may have implications for how the frozen continent reacts to the climate crisis, according to new research.
“People have assumed there might be deep groundwater in these sediments, but so far, no one has done any detailed imaging,” said study lead author Chloe Gustafson, a postdoctoral fellow in oceanography at the University of California’s Scripps Institute. California in San Diego, in a statement.
“Antarctica has 57 meters of sea level rise, so we want to make sure that we integrate all the processes that control how ice flows from the continent into the oceans. Currently groundwater is a missing process.” on our ice flow models,” he added in an email.
Searching for water in Antarctica
The ice sheet covering Antarctica is not all solid. In recent years, researchers in Antarctica have discovered hundreds of interconnected liquid lakes and rivers contained within the same ice. 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, published in Science Thursday, focused on the 60-mile-wide Whillans Ice Stream, one of six streams that feed the Ross Ice Shelf, the ice shelf the world’s largest ice cap, about 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 operate a technology called magnetic imaging.
This technology can detect the different degrees of electromagnetic energy being conducted by ice, sediment, freshwater rock, and saltwater and create a map from these various sources of information.
“We imaged from the ice layer to about five kilometers and even deeper,” 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 squeeze groundwater from the sediments in the 100 square kilometers they drew on the surface, it would be a lake 220 to 820 meters deep.
“The Empire State Building on the antenna is approximately 420 meters 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, the water will rise halfway above the Empire State Building. At the deep end, there are roughly two Empire State Buildings stacked on top of each other. This is significant because the subglacial lakes in this area are between 2 and 15 meters deep.” This is like one to four floors of the Empire State Building.”
How did they 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. It will likely continue to seep and mix with groundwater today, Key said.
The researchers said more work is needed 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 advancing toward the sea.
However, if the surface ice sheet is thin, the pressure drop may allow these deeper waters to flow. This upward movement will soften the base of the ice and speed up its flow.
“This discovery highlights groundwater hydrology as a potentially important piece in understanding the impact of water flow on Antarctic ice sheet dynamics,” writes Winnie Chu, associate professor at Georgia Institute of Technology, in a commentary on the research published in the journal. Science. She did not participate in the study.