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The tale of the mantle-plume thermal anomaly and the lost landscape 14 July 2011

Posted by admin in current research, geoscience.
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Using three-dimensional seismic reflection data, UK scientists have recovered the topography of a landscape that has been buried beneath the sea-floor sediments of the North Atlantic for 55 million years. The researchers, from the Bullard Laboratories and the BP Institute in Cambridge, have traced the coast, drainage patterns and contours of a landform that emerged north of what is now Scotland some 57-55 Myr ago, and have reconstructed the sequence through which the land was uplifted and, after about 1 million years of exposure, reburied. Their results are published in Nature Geoscience (see references below). They conclude that the driving force behind the rapid rise and fall of this large landmass was a thermal anomaly in the Icelandic mantle plume flowing beneath the lithospheric plate. The uplifted mass was located ~600 km from the centre of the Icelandic plume: a short-period thermal anomaly in the plume produced pulses of hot mantle material that spread out radially and caused the elevation of the landmass at the rapid rate of ~1km over two million years, and then its equally rapid subsequent disappearance.

The power of convective mantle processes is demonstrated once again. The result: a lost landscape sunk beneath the waves, just like Atlantis.

References
Ross A. Hartley, Gareth G. Roberts, Nicky White & Chris Richardson, ‘Transient convective uplift of an ancient buried landscape’, Nature Geoscience 2011 (advanced online publication, link to abstract only) doi:10.1038/ngeo1191
Heather Poore, Nicky White & John Maclennan, ‘Ocean circulation and mantle melting controlled by radial flow of hot pulses in the Iceland plume’, Nature Geoscience 2011 (advanced online publication, link is to abstract only) doi:10.1038/ngeo1161

News
A lost world? Atlantis-like landscape discovered – Live Science, 10 July 2011
Lost landscape discovered off the Scottish coast – BBC News, 14 July 2011

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