News

Scientists seek to unravel the Earth's mysteries

(1 March 2007)

A Durham academic is leading a major international research voyage to find out more about the Earth's structure.

Professor Roger Searle, a marine geophysicist, will head up a team of scientists on the inaugural research cruise of the new UK research ship RRS James Cook, which sets sail on Monday from Tenerife. Prof Searle is working with co-investigators at Cardiff and Southampton Universities. Scientists have previously found a large area hundreds of square kilometres in the middle of the Atlantic where the Earth's crust seems to be missing entirely. Instead, the mantle - the deep interior of the Earth, normally covered by crust many kilometres thick - is exposed on the seafloor, 3000m below the surface. The research cruise will attempt to answer some of the questions posed by this discovery by sailing to this area, which lies mid-way between the Cape Verde Islands and the Caribbean. The team intends to use sonars to image the seafloor and then take rock cores using a robotic seabed drill. The samples will provide a rare opportunity to gain insights into the workings of the mantle deep below the surface of the Earth. Professor Searle, from Durham University's Department of Earth Sciences, commented: "This is probably the first area where the mantle has been observed extensively on the seafloor. It gives us a unique opportunity to study this enigmatic part of the Earth in detail." "Our current theories suggest that as the tectonic plates separate, the mantle rises to fill the gap and, in doing so, partly melts." "The molten rock or magma is then emplaced on the seafloor through volcanoes to build new crust. It looks as though the melting may not be occurring here, and we may be looking at a wholly different way of creating and spreading the plates." The RRS James Cook was named by Princess Anne at the National Oceanography Centre in Southampton in January. Progress of the cruise can be monitored via a live web link to the ship and the public, and especially school children, are encouraged to ask questions of the scientists on board during the expedition via the on-line e-mail link. To monitor the progress of the cruise ship, please go to: http://www.noc.soton.ac.uk/gg/classroom@sea/JC007/