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Published online: 1 July 2009 | doi:10.1038/nchina.2009.138
Palaeogeography: Cold mountain
Felix Cheung
Abstract
Radar information reveals the landscape hidden underneath Antarctica's ice sheets
Original article citation
et al. The Gamburtsev mountains and the origin and early evolution of the Antarctic Ice Sheet. Nature doi:10.1038/nature08024 (2009).Introduction
© (2009) istockphoto.com/Alexander Hafemann
The Earth used to be a much warmer place, but about 34 million years ago, a sudden drop in atmospheric carbon dioxide levels caused the climate to cool. Ice sheets began to form on the mountain ranges of Antarctica, including the Gamburtsev Mountain Range at Dome A near the centre of Antarctica, burying beneath them rivers, peaks and valleys. An international team led by Sun Bo at the Polar Research Institute of China in Shanghai and Martin Siegert at the University of Edinburgh1 has now provided the first detailed depiction of the topography underneath the ice.
The researchers spent seasons in 2004/05 and 2007/08 conducting radar surveys of the Gamburtsev Mountain Range. The radar information revealed a landscape that looks similar to the European Alps — with features that could only have formed by glacial erosion, such as corries, steep cliffs, hanging valleys and valley steps.
The researchers estimated that for glacial erosion to occur, the region must have experienced a period in which mean summer surface temperatures reached only around 3 °C. Based on the climatic history of Antarctica, they believe the glacial erosion occurred about 14 million years ago, during the second episode of global cooling.
This latter finding is particularly important because it shows that ice at the centre of Antarctica has changed little over the last 14 million years.
The authors of this work are from:
Polar Research Institute of China, Shanghai, China; School of GeoSciences, University of Edinburgh, Edinburgh, UK; National Institute of Polar Research, Research Organization of Information and Systems, Tokyo, Japan.
Reference
- Bo, S. et al. The Gamburtsev mountains and the origin and early evolution of the Antarctic Ice Sheet. Nature doi:10.1038/nature08024 (2009). | Article |
