Mercer Subglacial Lake is a

subglacial lake A subglacial lake is a lake that is found under a glacier, typically beneath an ice cap or ice sheet. Subglacial lakes form at the boundary between ice and the underlying bedrock, where gravitational pressure decreases the pressure melting point ...

Antarctica Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean, it contains the geographic South Pole. Antarctica is the fifth-largest contine ...

covered by a sheet of ice thick; the water below is hydraulically active, with water replacement times on the order of a decade from the

Ross Sea The Ross Sea is a deep bay of the Southern Ocean in Antarctica, between Victoria Land and Marie Byrd Land and within the Ross Embayment, and is the southernmost sea on Earth. It derives its name from the British explorer James Clark Ross who vi ...

. Studies suggest that Mercer Subglacial Lake as well as other subglacial lakes appear to be linked, with drainage events in one reservoir causing filling and follow-on drainage in adjacent lakes.

Exploration

Helen Amanda Fricker from the

Scripps Institution of Oceanography The Scripps Institution of Oceanography (sometimes referred to as SIO, Scripps Oceanography, or Scripps) in San Diego, California, US founded in 1903, is one of the oldest and largest centers for oceanography, ocean and Earth science research ...

discovered Mercer Subglacial Lake in 2007, while using satellite laser altimetry to search for the grounding line of a glacier. The lake is named after

Mercer Ice Stream Mercer Ice Stream (), formerly Ice Stream A, flows west to Gould Coast to the south of Whillans Ice Stream, Antarctica. It is the southernmost of several major ice streams draining from Marie Byrd Land into the Ross Ice Shelf. The ice streams were ...

(formerly Ice Stream A), beneath which the lake is located. Mercer Ice Stream is named after the late

Ohio State University The Ohio State University, commonly called Ohio State or OSU, is a public land-grant research university in Columbus, Ohio. A member of the University System of Ohio, it has been ranked by major institutional rankings among the best publ ...

glaciologist John Mercer. On 28 December 2018, the Subglacial Antarctic Lakes Scientific Access (SALSA) Project, for which she serves on the project's executive committee, announced they had reached Mercer Subglacial Lake after two days of melting their way through of ice with a high-pressure hot-water drill. The drill water is run through filters that catch 99.9% of bacteria and particles, followed by UV light exposure and

pasteurization Pasteurization or pasteurisation is a process of food preservation in which packaged and non-packaged foods (such as milk and fruit juices) are treated with mild heat, usually to less than , to eliminate pathogens and extend shelf life. The ...

. The team obtained water samples for chemical and biological analyses, as well as samples of basal ice, and sediment cores as deep as .

Preliminary results

The lake water samples contains enough oxygen to support aquatic animals, and bacteria are present with a density of at least 10,000 cells per millilitre. Other ancient organisms retrieved from the sediments include shells of

diatom A diatom (Neo-Latin ''diatoma''), "a cutting through, a severance", from el, διάτομος, diátomos, "cut in half, divided equally" from el, διατέμνω, diatémno, "to cut in twain". is any member of a large group comprising sev ...

s (a photosynthetic algae) and thread-like plants or fungi. The sediment cores will also be analysed by geobiologists to study how relict organic matter deposited during marine incursions influences contemporary

biodiversity Biodiversity or biological diversity is the variety and variability of life on Earth. Biodiversity is a measure of variation at the genetic (''genetic variability''), species (''species diversity''), and ecosystem (''ecosystem diversity'') l ...

and

carbon cycling The carbon cycle is the biogeochemical cycle by which carbon is exchanged among the biosphere, pedosphere, geosphere, hydrosphere, and atmosphere of the Earth. Carbon is the main component of biological compounds as well as a major component ...

References

External links

Subglacial Antarctic Lakes Scientific Access
(SALSA) home page. {{DEFAULTSORT:Mercer Subglacial Lake (Antarctica) Subglacial lakes Lakes of Antarctica

Exploration

Preliminary results

See also

References

External links