March 28, 2013
Source Of Seafloor-Forming Magma Uncovered In New Seafloor Image
redOrbit Staff & Wire Reports - Your Universe Online
By using electromagnetic technology to map a large area of seafloor near Central America and the northern East Pacific Rise, researchers from the Scripps Institution of Oceanography report that they have a better idea of the origin of the erupted magma that eventually becomes new seafloor.Scientists have known for several decades that the seafloor is formed throughout the major ocean basins at the linear chains of volcanoes known as mid-ocean ridges. Now researchers at the institute, which is located at the University of California, San Diego, have captured an image of a location deep in the earth where the magma is generated.
Details of the image, which was captured using technology developed at the Scripps Institution, have been published in Thursday´s edition of the journal Nature. The information for the study was obtained during a 2004 expedition at the northern East Pacific Rise — a region where new seafloor is created as the Pacific and Cocos tectonic plates are spreading apart from one another — that was conducted onboard the US Navy research vessel Roger Revelle.
“Our data show that mantle upwelling beneath the mid-ocean ridge creates a deeper and broader melting region than previously thought,” Kerry Key, lead author of the study and an associate research geophysicist at Scripps, said in a statement. "This was the largest project of its kind, enabling us to image the mantle with a level of detail not possible with previous studies."
“We have been working on developing our instruments and interpretation software for decades, and it is really exciting to see it all come together to provide insights into the fundamental processes of plate tectonics,” added co-author Steven Constable, a professor at the UC San Diego Institute of Geophysics and Planetary Physics. “It was really a surprise to discover that melting started so deep in the mantle — much deeper than was expected.”
The electromagnetic technology used in the discovery was developed at Scripps back in the 1960s, and has been upgraded by Key and Constable over the past several years. Key said he believed that the technology will provide greater insight as it is further refined and the analysis techniques associated with it improve. He added that his team has plans to eventually use the technology to map subglacial lakes and groundwater in the polar regions.
In addition to Key and Constable, Lijun Liu of the University of Illinois and Anne Pommier of Arizona State University were co-authors of the study. The research was supported by the National Science Foundation (NSF) and the Scripps Seafloor Electromagnetic Methods Consortium.