What is hidden under the ice of Antarctica?

2024 Author: Seth Attwood | [email protected]. Last modified: 2023-12-16 15:55

Antarctic subglacial lakes stretch in pitch darkness and in complete isolation from the outside world, and therefore can harbor unique ecosystems. Scientists do not exclude that there may be life under the ice. Why lakes don't freeze and how they will help us in space exploration.

Hundreds of lakes may have been sealed from sunlight for a very, very long time.

Although the Antarctic continent is covered with ice several kilometers thick, it hides a landscape of hundreds of large and small lakes with non-freezing water.

The most famous among them is Vostok, the largest lake that scientists have discovered under a layer of ice at a depth of more than 4 thousand meters. Its length is 250 kilometers and its depth is 900 meters.

Some of these lakes stretch in pitch darkness and in complete isolation from the outside world, and therefore can harbor ecosystems that have not been in contact with those known to us for a very long time. There are about 250 lakes lurking between ice and rock in Antarctica, according to a new study published in Science Advances.

These lakes are of great interest to scientists who are exploring the possibility of life elsewhere in our solar system. For example, there may well be liquid seas under the ice on Jupiter's frozen moon Europa, and NASA recently decided to send a probe there in 2024.

Two researchers from the University of Cambridge have theoretically estimated how likely it is that these lakes, with their extreme conditions, could give rise to and sustain life.

Life under the ice?

Several lakes have already been investigated for the presence of microorganisms, and although there are no definite conclusions yet, it seems that in some places there may be microscopic life - for example, bacteria.

According to Nature, the bacteria were found in Lake Mercer, 1000 meters below the ice. But this lake is less isolated than possibly other subglacial lakes.

At the same time, it is quite possible that there are still undiscovered bacteria in Lake Vostok. But according to a 2016 study, it is very difficult to get perfectly clean water samples from there without contaminating them with microorganisms along the way.

As reported on the Internet resource Livescience, in 2017, several types of microorganisms were found in Lake Vostok.

Whether more complex life forms can exist in these lakes is not yet clear.

But where does liquid water come from?

Pressure and heat

From above, ice presses with all its weight on these lakes. Meanwhile, ice has the property of melting under pressure - this phenomenon is called rejection.

Thus, the outermost layer of ice melts, but the pressure remains so strong that the water in the under-ice lakes does not freeze back, although its temperature drops much below zero.

In addition, lakes are located deep in the earth's crust, and they are heated by the bowels of the planet. For example, Lake Vostok is located 500 meters below sea level.

This heating from below creates currents that can carry nutrients around the lake. According to a new study in Science Advances, the nutrients come from the ice that melts from above.

Currents may well create sufficient circulation for the distribution of nutrients and oxygen. Probably enough of it to keep the microorganisms alive.

New research is providing clues on where to look for potential life in these lakes. Lakes located under a layer of ice less than 3, 1 thousand meters will have a rather stagnant upper layer of water directly in contact with the ice. It mixes little with the rest of the water. Therefore, scientists recommend taking samples from the layer at least a meter below.

There are still many questions about what is happening in these subglacial lakes. In the future, perhaps scientists will drill wells to one of them - Lake CECs, named after the Research Center in Chile (Centro de Estudios Cientificos i Chile), whose employees discovered it.