Beneath the thick ice sheet that makes up West Antarctica It has a huge body of water connected by numerous underwater rivers and lakes.. This is the first time scientists have studied such systems, which exist deep within the frozen continent, with empirical evidence. to know them Key to shedding light on behavior and melting of Antarctic glaciers.
A research team from the Scripps Institution of Oceanography has become the first to map the secret underlying the Antarctic ice sheets and has published their results in the journal Science.
Scientists have been flying over the Antarctic ice sheet with radar and other instruments for decades to view underground features; but always with bad results. These tasks showed intertwined sedimentary basins between ice and bedrock, but could not predict water content or other features.. The evidence was there, but out of reach of the human hand.
However, this group of scientists has now uncovered that mystery. The researchers traveled to the western part of Antarctica, specifically the area near the Whillans Current, which is about 800 meters thick and one hundred kilometers wide and feeds the Ross Ice Shelf, considered the largest in the world. They knew that by examining this place with the right tools, they would be successful. And previous research at this place had revealed that beneath the ice there was a subglacial lake and a sedimentary basin lying beneath it. A few years ago, the outermost layer of ice was pierced and liquid water and a thriving microbe community were found. But what happened below remained a mystery..
The team used the magnetotelluric method, which measures the penetration of natural electromagnetic energy produced in the planet’s atmosphere to Earth, to obtain images of what lies deep within Antarctica. Because ice, seafloor sediments, fresh water, salt water, and bedrock all emit varying degrees of electromagnetic energy, you can measure the differences in these frequencies to create maps, just like an MRI.
The key to the behavior of glaciers
“The amount of groundwater we found was so significant that it likely affects ice flow processes.. Now we need to find more and figure out how to incorporate that into the models,” says Chloe Gustafson, lead author of the study. Many scientists say this. Liquid water is key to understanding the behavior of the frozen form found in glaciers, as meltwater is thought to lubricate the gravel and accelerate its movement towards the sea.
Additionally, these magnetotelluric signals gave researchers insight into groundwater properties, because “fresh water looks very different from salt water in our images,” Gustafson said.
In the second part of the study, the measurements were supplemented with data from seismic images collected by the study’s co-author Paul Winberry of Central Washington University. The analysis showed that, depending on location, the layer of sediment under the ice was more or less thick, from half a kilometer to almost two kilometers before reaching bedrock. A lake with a depth of 220 to 820 meters can be created with all the water in it.
It is unknown what effect these underwater lakes might have on the frozen continent’s marine dynamics, but researchers have begun to evaluate some of them. believed to be If the ice shelves were to melt due to global warming, ocean waters could re-invade the sediments and glaciers would risk raising global sea levels much more than anticipated.
The availability of subglacial groundwater also has effects on carbon stored by communities of microbes adapted to seawater, and could release “significant amounts” of this gas that were not previously thought of.
And also a lake as big as the island of La Gomera
Another different study, published in the journal Geology, made it possible to explore. Beneath three kilometers of ice in East Antarctica, specifically Princess Elizabeth Land, a 370-square-mile lake (same as the island of La Gomera) and contains a volume of 21 cubic kilometers of liquid water.
By analyzing this and other recently discovered subglacial lakes and the sediments they have at their bottom, You can learn the history of the ice sheet from its very beginning.Note the scientists from the University of Texas who are the authors of the study.
Specifically, it’s about unraveling what Antarctica was like before it froze, how climate change has affected it since the beginning of its history, and how current global warming is affecting it. The lake could hold a record of the last 34 million years of ice cover.
Reference Study: https://www.science.org/doi/10.1126/science.abm3301
……
Environment department contact address:[email protected]
Source: Informacion
