Thorne Lay

Distinguished Professor of Earth and Planetary Sciences. Seismologist who contributed to our understanding of the structure of the Earth's interior, the physics of earthquakes, mantle dynamics, and verification of the Comprehensive Nuclear Test Ban Treaty. Discovered that the lowermost mantle has a shear wave velocity discontinuity that is now generally attributed to a phase change in magnesium silicate perovskite.  Participated in development of the Asperity Model for fault slip heterogeneity that is the dominant conceptual framework for earthquake faulting. Demonstrated the existence of frequency dependence of seismic radiation with depth along megathrust faults.