Institution: | Institutos de Geofisica e Ingenieria, UNAM, CU, 04510 Mexico DF;Seismological Laboratory, California Institute of Technology, Pasadena, California 91125, USA;Instituto de Ingenieria, UNAM, CU, 04510 Mexico, DF;Seismologisches Zentralobservatorium, Krankenhausstrasse 1, 8520 Erlangen, Federal Republic of Germany |