Seismic Tomography of the Earth's Interior

The concept of plate tectonics, introduced nearly twenty years ago, unified many fields of earth science by providing a global framework for large-scale geological processes. Seismology played an important role in the formulation of this theory by supplying maps of global seismicity, delineating plate boundaries, producing evidence for deep subduction of the lithosphere, and determining the direction and nature of forces acting at plate boundaries.