Antarctica is home to roughly four hundred subglacial lakes.
The largest of these is Lake Vostok, found beneath Russia's Vostok station; it is the
sixteenth largest lake in the world by surface area and sixth by volume.
The lake was formed while Antarctica was still tropical and subtropical, but as the continents
began breaking away from the supercontinent Pangaea the lake eventually sank below layers
of ice and snow where it now rests 4,000 meters below the surface.
The lake water, being isolated from anywhere between 15 and 25 million years, has only
recently been reached.
Before the 1800s, no one expected there to be any unfrozen fresh water below the Earth's
poles.
However, at the end of the century, Russian scientist Peter Kropotkin suggested that the
intense pressure exerted by the ice could increase the temperature to a point where
water could remain liquid.
Another Russian scientist, in the 1950s and early 1960s, proposed that there was a body
of water below the ice sheet near Vostok Station; indeed, with remote sensing technology, Lake
Vostok's existence was proven in 1991.
Airborne radar experiments later backed this in 1996.
The lake itself is divided by an underwater ridge, with one portion being significantly
shallower than the other.
It is hypothesized that the ridge may be a hydrothermal vent, not unlike the black smokers
that help sustain life on the ocean floor at extreme depths.
Furthermore, geothermal heat warms the lake to -3 degrees Celsius, with the pressure of
the above ice preventing the liquid from freezing.
While seemingly an ordinary subglacial body of water, Lake Vostok may actually contain
a unique and isolated ecosystem.
Biologist Brent Christner, along with an international team, analyzed frozen lake water, called accretion
ice, found above Lake Vostok's surface and they discovered various microbes within the
collected samples.
These microbes likely obtain energy chemicals found in rocks due to the absence of sunlight.
Christner furthers this by say that "The types of organisms we found suggested they
derived their energy from minerals present in the lake and sources from the underlying
bedrock."
Ultimately, as an isolated ecological system, the organisms within the lake likely use recycled
carbon, nitrogen, and other necessary elements.
Additional studies conducted on these microbes revealed DNA that pertains to a wide variety
of single-celled organisms, dubbed extremophiles, found in streams, lakes, and oceans.
In 2013, with more in-depth DNA and RNA sequencing, researchers discovered thousands of species
hidden below Antarctica's ice.
This discovery listed fungi, archaea, and bacteria (often found in the digestive tracts
of various aquatic creatures) as some of the species.
They also noted that both psychrophiles (organisms that live in extreme cold) and thermophiles
(that live in relatively high temperatures) appear to live in Lake Vostok, alluding to
the presence of hydrothermal vents.
Furthermore, organisms appear to be both marine and freshwater species, which backs the theory
that the lake was once connected to the ocean.
Currently, Russian scientists at Vostok Station have extracted uncontaminated samples of the
lake's water, and are now analyzing the results.
Many scientists theorize, while still remaining conservative on their hypotheses, that the
lake could hold up 3,500 species.
These various discoveries, while revealing life below Antarctica's surface, also highlight
life's adaptability in the most extreme of conditions.
If life exists in Lake Vostok, it is not entirely improbable that life could exist elsewhere
in perhaps even more intense conditions.
For more infomation >> Ability Draft Tricks: ONESHOT combo! - Duration: 5:31. 
For more infomation >> Music & The Spoken Word: Presidents' Day Special - Live Stream February 18, 2018 - Duration: 1:22:37. 
For more infomation >> Super Mospy TV para dispositivos Android - Duration: 12:51. 
For more infomation >> Liberals Come Out in Favor of Voter Suppression – They Want to Block U.S. Soldiers from Voting! - Duration: 2:14. 
For more infomation >> BREAKING: Over 102 DEAD - Duration: 2:02. 
For more infomation >> এবার শাকিব খান ওমরসানী সহ ২০০ শিল্পীর সদস্যপদ বাতিল করছেন চলচ্চিত্র শিল্পী সমিতির জায়েদ খান | shakib - Duration: 3:34. 
For more infomation >> [VIETSUB] TÂN TẦM TẦN KÝ TẬP 38 PHIM XUYÊN KHÔNG 2018 HD - Duration: 47:11. 
Không có nhận xét nào:
Đăng nhận xét