The British Antarctic Survey has created the most extensive and intricate map of Antarctica’s subterranean environment to date, revealing that it is eminently more unstable, delicate, and perilous for rising sea levels around the world than previously anticipated.
To achieve this accomplishment, scientists used ice-penetrating radar, seismic surveying techniques, and satellite gravity observations to penetrate and map the average thickness (2 km) of the Antarctic ice sheet and analyze its internal properties. The mapped surface of Antarctica differs from that of many remote regions in that it reveals what looks like an otherworldly landscape.
Underneath the great volume of ice, which has been accumulating for approximately 34 million years in the form of snow, exists a vast hidden geographical landscape including mountain ranges, deep valleys, islands, great rivers, and approximately 700 bodies of liquid water. If the ice were to melt completely, the level of the global ocean will rise an estimated 60 meters.
A hidden world of liquid water and life
The second major finding is that there is a vast quantity of liquid water beneath the frozen surface of the coldest place on Earth.
(1) The pressure exerted on the melted ice surface by the ice sheet causes the temperature of water to drop below freezing,
(2) The geothermal flux of Earth’s interior causes temperatures to exceed the freezing point of water, and
(3) The thick insulation provided by the ice covering.
The discovery of Lake Vostok, which lay nearly two miles under the surface of the earth, changed everything. Lake Vostok is about the size of Ontario and has been sealed off for approximately 15 million years – Therefore, proving that Antarctica is not biologically dead. Further boring into the Whillans and Mercer lakes confirmed that there are living micro-organisms in these lakes living in total darkness under extreme pressure.
These sub-glacial lakes are important for more than just biology. They provide lubrication to the base of the icesheet, creating a way for the glaciers to slide more quickly to the ocean – therefore, increasing the sea level from below rather than above.
Volcanoes beneath the ice
Worse still is the volcanic action below the west Antarctic ice. The west Antarctic contains one of the largest volcanic regions on the planet. Over 100 volcanoes have already been identified as existing under kilometers of ice.
Unlike similar tectonic rift systems found in other areas of the world, the west Antarctic volcanic region is located over a rift system rather than over a subduction zone (like the pacific ring of fire). Therefore, the underground volcanic activity will melt the ice from below when the volcanoes erupt, which will lead to destabilizing the glaciers.
Models have shown that another issue resulting from climate change is that the reduction of pressure on the magma chambers due to the melting ice may cause further eruptions of the volcanoes – therefore creating a positive feedback loop that will create even more melting of the ice above it.
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Evidence from Earth’s past — and octopus DNA
Evidence of melt from Earth’s past is found in the evidence of octopus DNA; a genetic study showed that various, isolated populations of octopuses mixed about 125,000 years ago, meaning the West Antarctic Ice Sheet had to have largely collapsed at that time.
This mixing of octopus populations happened when sea levels were at least 10 meters higher than now. Geological records (Antarctica’s South Andes) show that with rapid melting of ice, there was a subsequent increase in volcanic activity.
Ice melts and volcanic eruptions are real processes, not just theories. Many scientists believe these processes contributed to the most recent “Snowball Earth” over the past hundreds of millions of years.
Why it matters now
West Antarctica has been contributing very little to the global sea level rise to date (just a few millimeters), but the evidence of melt suggests that if the West Antarctic Ice Sheet does collapse, it could happen much more quickly than was previously believed — that is, in centuries rather than thousands of years.
The potential collapse of the West Antarctic Ice Sheet should not just be seen as an interesting scientific story; it is a warning that decisions made today about climate change will determine how quickly Antarctica’s hidden world (the sea floor and ice sheets) will change our coastlines.
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