April 23, 2010 - Present
- Hugh Roy and Lillie Cranz Cullen Distinguished University Chair in Physics
- Professor, Dept. of Physics
- Professor, Dept. of Earth and Atmospheric Sciences
- University of Houston, Houston, Texas.
September 1, 2002 – April 23, 2010
- Hugh Roy and Lillie Cranz Cullen Distinguished Professor in Physics
- Professor, Dept. of Physics
- Professor, Dept. of Earth and Atmospheric Sciences
- University of Houston, Houston, Texas.
January 1, 2001 - Present
- Director
- Mission-Oriented Seismic Research Program
- University of Houston, Houston, Texas.