What lies beneath Antarctica’s kilometers-thick ice sheet has remained largely unknown until now. But a new map prepared by scientists has revealed the continent’s under-ice landscape in an unprecedented level of detail.
In the study published in Science, one of the most respected journals of the scientific world, researchers calculated how the land structure under the ice was shaped by examining the ice surface of Antarctica with satellite observations and using the physics rules that explain how glaciers flow. The results revealed thousands of previously unknown peaks, ridges and subterranean mountain ranges.
The lead author of the study, Dr. Helen Ockenden describes the resulting map as “going from a blurry film camera to a high-resolution digital image.” According to Ockenden, the structure of Antarctica under the ice can now be seen more clearly than ever before.
Until now, scientists have used ground or airborne radar measurements to see beneath the ice. However, these measurements were usually made along lines tens of kilometers away from each other, and the gaps were filled with assumptions. In the new method, small shape changes on the ice surface and differences in flow speeds were analyzed and traces of the underlying rock structure were followed.
Researchers liken this situation to understanding the underlying rocks from the eddies on the surface of the water while rowing in a stream. As ice flows over rock ridges and hills, it changes both its surface shape and speed; This gives clues about the topography under the ice.
In particular, the new map reveals in detail some hidden mountainous areas in East Antarctica and a giant underground channel in the Maud Underground Basin, approximately 400 kilometers long, 50 meters deep and 6 kilometers wide. The length of this canal corresponds to the distance between London and Newcastle as the crow flies.
According to researchers, the map is not precise and final; Assumptions about the flow of ice involve certain uncertainties, and much remains unknown about the rocks and sediments beneath the ice. Despite this, the study is considered an important turning point in the scientific world.
It will allow modeling of how it will act in the future.
Experts emphasize that this level of detail will allow more accurate modeling of how Antarctic glaciers will move in the future. Because the mountains, valleys and channels under the ice directly affect the speed and retreat of the glaciers.
This may make it possible to provide clearer answers to the questions of how much the melting in Antarctica may accelerate and to what extent this will contribute to global sea level rise. The future melting rate of Antarctica is still one of climate science’s biggest unknowns, scientists say.
Source: Newspaper Oxygen