March 22, 2007
Deep-diving West Coast Plate may have triggered the massive Central U.S. quake - Scientists studying extraordinary earthquakes in the central U.S. in 1811-12 along the New Madrid seismic zone have revealed a possible new driving mechanism. Remnants of the ancient Farallon plate, a slab of crust swallowed beneath the western North American continental margin nearly 70 million years ago, continue to descend into the deep mantle under central North America. The descent induces mantle flow towards the Earth’s deep interior directly below the New Madrid seismic zone. That flow, in turn, may strain the overlying crust, causing seismic ruptures.