Department of Geology and Geophysics, University of Wisconsin-Madison, 1215 W. Dayton St., Madison, WI 53706 United States
Department of Geology and Geophysics, University of Wisconsin-Madison, 1215 W. Dayton St., Madison, WI 53706 United States ;
Seismological Laboratory, California Institute of Technology, 1200 E. California Blvd., MS 252-21, Pasadena, CA 91125 United States ;
Instituto de Geofisica, Universidad Nacional Autonoma de Mexico, Ciudad Universitaria, Del Coyoacan, Mexico, DF 04510 Mexico ;
Departamento de Geografia y Ordenacion Territorial, Universidad de Guadalajara, Av. de los Maestros y Mariano Barcena, Planta Alta, Guadalajara, Jal 44260 Mexico ;