On the driest and coldest continent, scientists from Rice University in the United States have discovered streams of water flowing under the ice. The study was published in the journal Nature Geoscience.
For two years, scientists have been analyzing sediments and studying maps of the Ross Sea floor. Even 15,000 years ago, this area was covered with a thick layer of ice. Later, the glacier retreated hundreds of miles inland. The maps compiled by the Nathaniel B. Palmer National Science Foundation research vessel show ice retreat since the last ice age, showing ancient streams and subglacial lakes in several locations.
Today Antarctica is covered with ice, the thickness of which reaches 3.2 km in some places. Nevertheless, the ice layer is not static: under the influence of its own weight, it moves, and underground rivers of ice flow to the sea. According to ground-based observations, some of these streams move at a speed of several hundred meters per year. However, the ice itself can only overcome a few tens of meters per year. Based on this, scientists suggested that it moves with the help of external forces.
Since it is difficult to make observations under the ice, the authors of the study argue that the fossil river system illustrates how melt water flows out of subglacial lakes and flows into the ocean through channels. The water is melting due to the intense pressure of the glacier and due to the action of underground volcanoes, which can heat the ice from below. More than 20 lakes have been found in the subglacial river basin.
The results of the study can help hydrologists predict how modern glacial flows will behave and what their role in sea level rise is.