Puzzle of Antarctica’s Ice Covered Mountains has been solved
Gamburtsev Mountains are present below more than one mile of ice cover in Antarctica. They are a matter of surprise for scientists, since their discovery in 1958.
Scientists have solved the puzzle of the presence of mountains there in the depth and the role they played in the spread of glaciers over the continent 30 million years ago.
This research was funded by grants from the U.S. National Science Foundation and has been published online in the November 16 issue of the journal Nature.
An international team of researchers, in 2008-2009, flew over Antarctica’s deep interior with ice penetrating radar, magnetometers and gravity meters to get the information about the peaks and valleys hidden below the ice. The data, they gathered, helped in the information about how the mountains came into being. About one billion years ago, contents collided and the oldest rocks that make up the Gamburtsevs smashed together. Because of collision, thick crustal root formed deep in the mountain range. With the passage of time, these ancient mountains wear away but the cold dense root remained.
Within 250-100 million years ago, while the dinosaurs were the inhabitants of Earth, the supercontinent of Gondwana, which included Antarctica, moved away resulting in the old crustal to warm. Mountains were reformed because of reactivating the crustal root and the East Antarctic Rift, which pushed the land upwards again. Deep valleys and raised peaks resembling the European alps were formed by the rivers and glaciers. The East Antarctic Ice Sheet with an area of about 10 million square kilometers – about the size of Canada – formed about 34 million years ago, protected the mountains from erosion.
Robin Bell, study co-author and a geophysicist at Columbia University’s Lamont-Doherty Earth Observatory, said,
It has been almost a billion years since the Gamburtsev first formed. This work shows that very old mountains can rise again, like a Phoenix from the ashes. The Gamburtsevs rose from the long eroded East Antarctic craton.
Fausto Ferraccioli, study lead author and a scientist at British Antarctic Survey, said,
It was fascinating to find that the East Antarctic rift system resembles one of the geological wonders of the world – the East African rift system – and that it provides the missing piece of the puzzle that helps explain the Gamburtsev Subglacial Mountains. The rift system was also found to contain the largest subglacial lakes in Antarctica.
Reference:
Fausto Ferraccioli, Carol A. Finn, Tom A. Jordan, Robin E. Bell, Lester M. Anderson & Detlef Damaske, (2011). East Antarctic rifting triggers uplift of the Gamburtsev Mountains. Nature, doi:10.1038/nature10566
