World's deepest point on land

The researchers found an abyss below the Denman Glacier located 3.5km below sea level, just below the depth of oceanic trenches.

World's deepest point on land
Denman depression. (Photo: BBC).

The team discovered the basin across the most detailed mapping project of the soil beneath Antarctica. BedMachine is a topographic map of Antarctica showing peaks, gullies, and slopes. An international team led by glaciologists at the University of California, Irvine, mapped based on more than 40 years of data from 19 institutions. The team also used radar and satellite images to calculate the thickness of the ice and underlying soil over a large area.

The map and accompanying findings are published in the journal Nature Geoscience. Mathieu Morlighem, the study’s leader, realized that if they wanted to model the ice sheet more accurately, they needed a better map of the underlying rock. Then, Morlighem devised a new technique to observe the land under the ice, using satellite data of surface changes, snow accumulation, radar data.

“The biggest challenge is that Antarctica is so big, bigger than the US and Mexico combined, so applying this method to the entire coastal area is very time-consuming. It took us five years to come up with BedMachine.” Morlighem shared.

However, after completing the map, the team was able to explore previously unknown features of the land beneath the ice. A big surprise for them was the depression of the Denman Glacier . Thanks to the new technique, the researchers were able to calculate the Denman depression 3.5km above sea level, setting a record for the deepest point on land. This depression is about 100km long and 20km wide. For comparison, the deepest point on Earth is Cape Challenger Deep in the Mariana Trench in the Pacific Ocean with a depth of nearly 11km.