Scientists who drilled Mercer Lake, a subglacial Antarctic lake enclosed less than 3500 feet (one kilometer) in ice, discovered the ancient carcasses of small animals, including "water bears," in a discovery that scientists described as "totally unexpected".
On December 26, researchers funded by the US National Science Foundation. UU (NSF) managed to melt a hole through the thick ice in the water below. A report in the journal Nature said that the Scientific Access Equipment of the Antarctic Subglacial Lakes (SALSA) "melted through a huge frozen river with a high-pressure hot water drill."
The water below the ice sheet is hydraulically active and is connected to the Ross Sea and it has been identified that Lake Mercer has a high risk of collapsing with the West Antarctic ice sheet due to global warming. This is only the second time that humans have glimpsed the content of the lake and the massive scientific operation was carried out with technologies that include "ice penetration radar and other remote sensing techniques," according to the Nature article.
Main: cross section of an artist showing the drilling process to reach the lake (public domain). Box: Lake Mercer (CC by SA 3.0)
Rediscovering the ancient underwater life
The Guardian reported that scientists took samples of mud from the bottom of the frozen waters of the lake and found "tendrils of plants or fungi and remains of photosynthetic algae that lived and died in the area millions of years ago when Antarctica was much hotter" . the researchers later discovered crustacean-like shrimp and eight-legged tardigrades, or "water bears," which are described as smaller than poppy seeds.
David Harwood, a micro-paleontologist at the University of Nebraska-Lincoln, told reporters in Nature that discovering the animals in the ancient lake was "totally unexpected," but what really surprised the biologists at Lake Mercer was the understanding that some of the landlord beasts
Scientists know that these ancient creatures inhabited the ponds and streams of the Transantarctic Mountain when the glaciers had receded during the hot periods between 10,000 and 120,000 years ago. But one outstanding problem is that these crustaceans and beasts inhabit ponds about 80 miles (80 miles) from Lake Mercer, and it is not yet clear how they got there.
Tardígrados with a scanning electron microscope (CC by SA 2.5)
DNA could provide answers to the ancient origins of creatures
In 5 th In January, the scientists closed the well and believe that it will take several years to analyze and analyze all the samples collected. They need to analyze DNA samples from the corpses of the crustaceans to determine if they were marine or freshwater species. The SALSA team also aims to determine the age of organic material with carbon dating and will also sequence the creatures' DNA to try to answer how, when and to what extent Antarctic glaciers retreated for millennia.
In 2013, Slawek Tulaczyk, a glaciologist at the University of California at Santa Cruz, was co-leader in a drilling expedition at Lake Whillans, a subglacial lake in Antarctica, 50 kilometers (31 miles) from Lake Mercer. Tulaczyk, who has been studying sediment samples from lakes under glacial ice since the 1990s, told The Guardian that "such a thing has never been found under the ice sheet before." Filled with microbes, they had not observed any "sign of higher life," like the one discovered at Mercer Lake.
The general idea of lakes under the frozen cover of Antarctica was not really considered until the 1990s, when satellite seismic mapping technologies and ice penetration radar began to reveal evidence of subglacial lakes. Now, almost 400 are known to scientists, all fed by the base of the ice sheet that scientists estimate at a few millimeters per year. However, this is not caused by global warming, but by the omission of environmental heat from deep within the planet.
Top image: Coast of Antarctica with centenarian thickness of glaciers (sichkarenko_com / Adobe Stock )
By Ashley Cowie