Gamburtsev Mountains problem disentangle in interior East Antarctica

The birth of the Gamburtsev Subglacial Mountains buried beneath the vast East Antarctic Ice Sheet — a puzzle mystifying scientists since their first discovery in 1958 — is finally solved. The remarkably long geological history explains the formation of the mountain range in the least explored frontier on Earth and where the Antarctic Ice Sheet first formed. The findings are published this week in the journal Nature.

A seven-nation team of scientists explored the Gamburtsev Subglacial Mountains — buried beneath up to 3km of ice — during the International Polar Year (2007–09) by using two twin-engine aircraft equipped with ice penetrating radars, gravity meters and magnetometers.

By analyzing the new data, the researchers describe the extraordinary processes — which took place over the last billion years — that created and preserved a root beneath the mountains and the East Antarctic rift system — a 3,000km long fracture in the earth’s surface that extends from East Antarctica across the ocean to India.

One billion years ago, before animals and plants evolved on Earth, several continents (or micro-continents) collided, crushing the oldest rocks of the mountain range together. This event formed a thick crustal root extending deep beneath the mountain range. Over time these ancient mountains were eroded but the cold dense root was left behind.

Around 250–100 million years ago — when dinosaurs walked the Earth — rifting paved the way for the supercontinent Gondwana to break apart, which included Antarctica, causing the old crustal root to warm. This rejuvenated crustal root, together with the East Antarctic Rift forced the land upwards again reforming the mountains. Rivers and glaciers carved deep valleys and this helped uplift the peaks to create the spectacular landscape of the Gamburtsevs, which resemble the European Alps. The East Antarctic Ice Sheet, which formed 34 million years ago and covers 10 million km2 of our planet (an area the size of Canada), protected the mountains from erosion. Source: http://www.antarctica.ac.uk/press/press_releases/press_release.php?id=1641