The deepest point on land has been found in East Antarctica -- underneath the Denman Glacier. The ice-filled canyon goes down 3,500 meters (or 11,500 feet) below sea level. In fact, the only other places on Earth where the valleys are deeper are found solely in the ocean.
Researchers analyzed the amount of ice that flows through Denman trough every year and found out that it would have to be at least 11,000 feet below sea level in order for all of the ice to pass through.
For comparison, the deepest point on land prior to this discovery in Antarctica was located at the Dead Sea Shore and measured 432 meters (or 1,419 feet) below sea level. There are actually land canyons located on Earth that have taller sides but their floors are still above sea level (like the Yarlung Tsangpo Grand Canyon located in China). As for the lowest point in the ocean, Mariana Trench in the western Pacific Ocean is around 11 km below the surface of the water.
Researchers were able to illustrate a map, called BedMachine Antarctica, with great detail of the continent that shows the shape of the bedrock that’s underneath the ice, as well as seismic measurements, ice movement measurements, and radar points. By doing this, they’ll have a better understanding of the future climate changes that could affect the polar south. For example, they discovered previously unseen ridges that could delay the retreat of the glaciers. On the other hand, they noticed several smooth sloping terrains that could speed up the process.
Dr. Mathieu Morlighem, who is an Earth system scientist at the University of California, Irvine, and the lead author of a paper about the map, said, “This is undoubtedly the most accurate portrait yet of what lies beneath Antarctica's ice sheet.” In a statement (which can be read in full here), he explained that, “Using BedMachine to zoom into particular sectors of Antarctica, you find essential details, such as bumps and hollows beneath the ice that may accelerate, slow down or even stop the retreat of glaciers.”
The map, which was published in the journal Nature Geoscience (and can be read here), shows different topographical features that have never been seen before. The authors explained that the previously unknown features have “major implications for glacier response to climate change,” adding, “For example, glaciers flowing across the Transantarctic Mountains are protected by broad, stabilizing ridges.” Several pictures of the map can be seen here.
Dr. Emma Smith, who is from Germany’s Alfred Wegener Institute, used an interesting analogy, “Imagine if you poured a bunch of treacle on to a flat surface and watched how it flowed outwards. Then pour the same treacle on to a surface with a lot of lumps and bumps, different slopes and ridges - the way the treacle would spread out would be very different. And it's exactly the same with the ice on Antarctica,” she told BBC News.
This is definitely an interesting discovery, as Antarctica is a fascinating continent that has been the subject of many studies over the years.