Scientists discover huge reservoir of magma under Pacific and Cocos plates

March 28, 2013 – CENTRAL AMERICA – Since the plate tectonics revolution of the 1960s, scientists have known that new seafloor is created throughout the major ocean basins at linear chains of volcanoes known as mid-ocean ridges. But where exactly does the erupted magma come from? Researchers at Scripps Institution of Oceanography at UC San Diego now have a better idea after capturing a unique image of a site deep in the Earth where magma is generated. Using electromagnetic technology developed and advanced at Scripps, the researchers mapped a large area beneath the seafloor off Central America at the northern East Pacific Rise, a seafloor volcano located on a section of the global mid-ocean ridges that together form the largest and most active chain of volcanoes in the solar system. By comparison, the researchers say the cross-section area of the melting region they mapped would rival the size of San Diego County. Details of the image and the methods used to capture it are published in the March 28 issue of the journal Nature. “Our data show that mantle upwelling beneath the mid-ocean ridge creates a deeper and broader melting region than previously thought,” said Kerry Key, lead author of the study and an associate research geophysicist at Scripps. “This was the largest project of its kind, enabling us to image the mantle with a level of detail not possible with previous studies.” The northern East Pacific Rise is an area where two of the planet’s tectonic plates are spreading apart from each another. Mantle rising between the plates melts to generate the magma that forms fresh seafloor when it erupts or freezes in the crust. –Science Daily