Newly discovered lake may hold secret to the rise and fall of the Antarctic ice sheet – Rise for it?
UNIVERSITY OF TEXAS IN AUSTIN
CREDIT: SHUAI YAN / UT JACKSON SCHOOL OF GEOSCIENCES
Scientists investigating the underside of the world’s largest ice sheet in East Antarctica have discovered a city-sized lake whose sediments may contain the ice sheet’s history dating back to the earliest times. its first day. That would answer questions about how Antarctica was before it froze, how climate change has affected it throughout its history, and how the ice sheet may behave as the world warms. .
Discovered by powerful instrumented polar research aircraft, Snow Eagle Lake is covered by 2 miles of ice and lies in a mile-deep canyon in the highlands of Princess Elizabeth Land in Antarctica, off the coast several hundred miles.
“This lake has the potential to document the entire history of the East Antarctic Ice Sheet, its beginning more than 34 million years ago, as well as its development and evolution through the glacial cycles since then. ,” said polar expert Don Blankenship, one of the paper’s authors and a senior research scientist at the University of Texas at Austin’s Institute for Geophysics. “Our observations also suggest that the ice sheet changed dramatically about 10,000 years ago, although we don’t know why.”
Because it is located relatively close to the coast, the researchers suggest that Snow Eagle Lake may contain information about how the first East Antarctic Ice Sheet began and the part that played the role of the Antarctic Current, a ring of cold water surrounding the continent that scientists think is responsible. to keep it cool.
The study appears May 9 in the journal Geology.
The first hint that the lake and its host canyon existed when scientists discovered a flat depression in satellite images of the iceberg. To confirm it was there, the researchers spent three years flying systematic surveys of the site with ice-penetrating radar and sensors that measure small changes in Earth’s gravity and magnetic fields. land.
The paper’s lead author, Shuai Yan, a graduate student at UT Austin’s Jackson School of Geosciences, who planned the flight for the field study investigating the lake.
What Yan saw was the lake’s water, which, unlike ice, reflected radar like a mirror. Along with surveying gravity and magnetic fields, unraveling the underlying geology of the area as well as water and sediment depths, Yan built a detailed picture of the jagged highland terrain with Snow Lake Eagle nestles at the foot of a canyon.
The newly discovered lake is about 30 miles long, 9 miles wide and 650 feet deep. The sediments at the bottom of the lake are 1,000 feet deep and may include river sediments older than the ice sheet itself.
Going forward, the researchers say, taking a sample of the lake’s sediments by drilling into it will fill a huge gap in scientists’ understanding of Antarctic glaciation and provide important information. about the collapse of the ice sheet due to climate change.
“This lake has been accumulating sediment for a very long time, potentially taking us through a period when Antarctica was completely ice-free until it was deep-frozen,” said co-author Martin Siegert, the bank study at Imperial College London, said. “We don’t have a record of all of those events in one place, but this lake bottom sediment could be ideal.”
Snow Eagle Lake is named after one of the planes used in its exploration. It is one of many features discovered by ICECAP-2, an international collaboration to map the last unknown regions of East Antarctica by polar research groups from the US, UK, China, Australia, Brazil and India. The research team for this paper included scientists from UTIG, the Scripps Institute of Oceanography, Imperial College London, the Australian Antarctic Division and the China Polar Research Institute. The research was supported by the G. Unger Vetlesen Foundation and funded by the governments and organizations of the countries involved.
JOURNEYS
Geology
DOI
RESEARCH METHODS
Observational research
RESEARCH SUBJECTS
Do not apply
ARTICLE TITLE
A newly discovered sub-glacial lake in East Antarctica likely holds a valuable sedimentary record on ice and climate change
ARTICLE PUBLICATION DATE
May 9, 2022
Related
