Surface Ruptures Observed at Ejido Saltillo, Baja California after the Mexicali Valley Earthquake of 9 June, 1980

Abstract

Following the 9 June 1980 earthquake near Victoria, Baja California, J. J. Lienkaemper and I briefly investigated the Imperial fault in California to determine whether a new pulse of after slip of the 15 October 1979 earthquake might have been triggered by the new seismic event. On June 12, we checked the Imperial fault in Mexico for evidence of new displacement, as well as several locations along the Cerro Prieto fault in the epicentral region (Figure 7.1). On returning by way of Ejido Saltillo, our car reported a vertical offset in the pavement of Pascualitos-Pescaderos highway with a provocative jolt. The local farmers’ knowledge of new ruptures greatly expedited our subsequent observations, which are briefly summarized here.