New data shakes accepted models of collisions of the Earth's crust

Eric Calais, a Purdue associate professor of geophysics, shows equipment he used to track movements of the continent of Asia over a 10-year period. In his right hand, Calais holds an example of the geodetic markers he and his team drilled into the Earth's surface to track movements as small as one millimeter. The data he collected addressed the 40-year debate over how continents respond during collisions of tectonic plates. Credit: Purdue News Service photo/David Umberger