This map shows Earths surface superimposed on a depiction of what a new University of Utah study indicates is happening 1,800 miles deep at the boundary between Earths warm, rocky mantle and its liquid outer core. Using seismic waves the probe Earths deep interior, seismologist Michael Thorne found evidence that two continent-sized piles of rock are colliding as they move atop the core. The merger process isnt yet complete, so there is a depression or hole between the merging piles. But in that hole, a Florida-sized blob of partly molten rock -- called a mega ultra low velocity zone -- is forming from the collision of smaller blobs on the edges of the continent-sized piles. Thorne believe this process is the beginning stage of massive volcanic eruptions that wont occur for another 100 million to 2100 million years.