Скачать или смотреть The Mysterious Continent at the Edge of the World: What Lies Beneath Antarctica?

The Mysterious Continent at the Edge of the World: What Lies Beneath Antarctica?
Scientific Research
The Antarctic ice sheet is melting more each year due to global warming. In the coming decades, it is likely that parts of the continent will be ice-free. This prompts scientists to investigate, "What's beneath the ice?"

Around 34 million years ago, Earth experienced significant climate change, resulting in an entire continent being buried under ice. However, the exact nature and location of this change remained unknown. Additionally, why is West Antarctica melting faster than East Antarctica? Scientists from the Alfred Wegener Institute and the Helmholtz Polar and Marine Research Center decided to investigate these questions.

A recent study published in the journal Science suggests that the underlying cause may be the different periods during which the ice sheets formed. Surprisingly, during the early phase when Antarctica began turning into a snowy land, there were no signs of ice in West Antarctica.

The seabed off Pine Island and Thwaites Glaciers in West Antarctica is so hard that traditional drilling methods couldn't reach the deep sediments. The MARUM-MeBo70 seabed drilling device, with its rotating and cutting head, made it possible to drill about 10 meters into the seabed and collect samples.

The findings confirm that permanent ice formation in Antarctica began around 34 million years ago but was limited to the eastern parts, not covering the entire continent as previously assumed. According to researchers, the climate conditions necessary for permanent ice formation existed only in East Antarctica, particularly in the northern coastal regions of Victoria. Moist air masses rose to the Transantarctic Mountains, creating conditions for heavy snowfall and thick ice sheet formation. The ice sheet then spread inland, quickly covering East Antarctica. However, it took at least 7 million years for the ice to reach West Antarctica, which was still largely forested and had a cool-temperate climate preventing ice formation.

Dr. Johann Klages, a geologist at AWI and leader of the research team, stated, "Even slight warming is sufficient to melt the ice in West Antarctica, and we are currently at that point." This inevitably raises the question: What does Antarctica look like without ice?

Antarctica is covered by an ice sheet with an average thickness of 2.2 kilometers, concealing rugged mountains, volcanoes, and large canyons. Over 97% of the continent has been ice-covered for millions of years, with the thickest ice reaching about 4.9 kilometers.

Decades of satellite data and radar research have allowed for an incredibly detailed view of this hidden geography. One of the most detailed maps of the southernmost continent was created in 2019 as part of the BedMachine Antarctica project.

BedMachine Antarctica was a major project involving 19 research institutions from around the world, including NASA, the University of California, the National Natural Science Foundation of China, and the British Antarctic Survey.

The map is astonishing, providing an X-ray-like view of the ice-covered continent. It is also of scientific importance, helping researchers use the data to gain insights into Antarctica's topography and the future of its ice sheets.

One of the map's biggest surprises is the size of the canyon beneath Denman Glacier. The Denman Trough, at 3,500 meters below sea level, is the deepest point on Earth. However, ice is only one part of this extreme geography. Antarctica's lesser-known feature is its volcanic activity. Paradoxically, this frozen continent has a significant number of volcanoes. A 2017 study identified 138 volcanoes in West Antarctica alone. While most are inactive, eight or nine are known to be active.

Mount Erebus, at 3,794 meters, is the highest active volcano in Antarctica. Interestingly, scientists discovered in 1991 that the gas emitted by the volcano contained tiny metal gold crystals. It is estimated that the volcano releases about 80 grams of gold daily.

You might think of Antarctica as a cold, boring ice mass at the world's edge. However, a closer look reveals a land of ice filled with secrets and fascinating stories.

Sources: phys.org, IFL Science, and New Scientist archives.