Mysteries and Legends of the Gamburtsev Mountains



by LORENZO CIOTTI

Mysteries and Legends of the Gamburtsev Mountains

For geologists, the Gamburtsev Mountains are a real mystery: they are far from contact points between tectonic plates and do not appear to have been generated by volcanic activity. Moreover they must be relatively recent, otherwise they would have been flattened by the erosion of the ice.
The Gamburtsev Mountains are a subglacial mountain range of the Antarctic continent, in one of the most inaccessible places on the planet, not far from the pole of inaccessibility.

They were discovered in 1958 by the Third Soviet Antarctic Expedition and were named Gamburtsev after the Russian geologist and seismologist Grigoriy Aleksandrovich Gamburtsev. They stretch in length of about 1200 km with peaks reaching 3,400 m above sea level.

Even the highest peaks are covered by a blanket of ice no less than 600 meters thick. It was possible to deduce its appearance only thanks to Landsat satellites with sensors that allow you to cross the thick layer of ice. The result of the 2007-2009 study has found that the Gamburtsev are very old, first forming around a billion years ago when continental drift pushed two plates together to form the super-continent of Rodinia.

This early range was eroded above the surface but left a deep cold root, which is visible today in seismic images, reaching down into the Earth's mantle. About 250-100 million years ago, the crust started to pull apart in a series of rifting events close to the east of this old root.

A forked rift valley runs along the northern side of the mountains containing lakes Sovetskaya and 90East within it. This rifting warmed and rejuvenated the root, giving it the buoyancy to be lifted up to re-establish the mountains as an 800 km long massif.

Further uplift still was achieved as deep valleys were later cut erosion lightening the overall mass of the system. Around 35 million years ago, the glaciers merged to form the East Antarctic Ice Sheet, burying the Gamburtsev Range in the process.

Scientists announced the completion of their mission on 25 February 2009. The gathered data will be analysed by researchers in the following months. Dr Fausto Ferraccioli from the British Antarctic Survey said: "We can confirm they are there; we've seen them under the ice.

Not only are they similar in dimension to the European Alps, but they are also similar in aspect: we see very sharp peaks and valleys which are remarkably similar to the Alps themselves. It all adds to the mystery, from the tectonic perspective of how these mountains were created; and from the glacial history perspective of how the East Antarctic ice sheet was formed and didn't erode these peaks."