Jakarta, CNN Indonesia —
NASA reveals there are two lakes hidden under a layer of ice Antartika. The discovery was made using the advanced Ice, Cloud and land Elevation Satellite 2 (ICESat-2) tool that allows experts to get more accurate mappings.
The satellite, which is the most advanced laser device NASA has ever flown in space, measures the height of the ice surface, which, although up to thousands of meters in height, can increase or decrease as the lake water hidden beneath it dries up or increases.
ICESat-2 discovered two new lakes as it panned from space. In addition, it was also found that there is a water system that can affect the speed of ice towards the Southern Ocean, thereby adding fresh water and then potentially changing its circulation and ecosystem.
According to NASA in the site, a study on this subject, published July 7 in Geophysical Research Letters.
The water system beneath the previous Antarctic ice sheet has been a mystery for decades. But that changed in 2007, when Helen Amanda Fricker, a glaciologist at the Scripps Institution of Oceanography at the University of California San Diego, made a breakthrough that helped renew classical understanding of subglacial lakes in Antarctica.
Using data from ICESat’s predecessor satellite in 2007, Fricker found for the first time there is a fast-flowing Antarctic ice stream, and the entire lake network is connected to one another, and is actively filling and draining over time.
Previously, these lakes were thought to hold water from statically melted ice, without filling and draining water.
“The discovery of this interconnected lake system at the interface of the ice sheet moving the water, with all of these impacts on glaciology, microbiology, and oceanography—it was a major discovery of the ICESat mission,” said Matthew Siegfried, assistant professor of geophysics at the Colorado School of Mines, Golden, Colorado and lead investigator on the new study.
Scientists also hypothesize that subglacial water in Antarctica is the result of a combination of factors, including pressure fluctuations exerted by the large weight of the ice above, friction between the ice sheet, and the rock beneath, to heat coming from beneath the earth.
This is in stark contrast to the Greenland ice sheet, where lakes at the bottom of the ice are filled with meltwater that has flowed through cracks and holes in the surface.
To study areas where subglacial lakes fill and drain more frequently with satellite data, Siegfried worked with Fricker. They created the ICESat-2 mission to observe polar ice from space.
Siegfried and Fricker’s new research shows that a group of lakes, including lakes Conway and Mercer beneath the Mercer and Whillans ice flows in West Antarctica, are experiencing a period of drying for the third time since the initial ICESat mission to measure changes in elevation on the surface of the ice sheet in 2003. Two lakes newly discovered ones are also in this region.
In addition to providing important data, this study also reveals that the outline or boundaries of a lake can change gradually as water enters and leaves the reservoir.
“We’re literally mapping every elevation anomaly that exists today. If a lake is filling and draining, we’ll detect it with ICESat-2,” Siegfried said.
(ryh / fea)
– .
