Seismicity and Tectonics of the Northern Gulf of California Region, Mexico. Preliminary Results

Abstract

Three new seismographic statioms have been established· in the
\nnorthern Gulf of California region; Mexico. Seismicity ,during a
\nrepresentative period in April and May of 1969 was concentrated
\non the Imperial, San Jacinto, Sierra Juarez, .and San Miguel
\nfaults, and the spread of epicentral locations was m\\!Ch less than
\nhad previously been indicated. An intense earthquake swarm in
\nMarch of· 1969 occurred near Consag Rock in the northern Gulf,
\nand its study contributes to our understanding of the regional
\ntectonics. In the northern Gulf of California and adjacent Salton
\ntrough, the tectonic framework may be. approximated by a series
\nof six transform faults connected by five spreading centers (ridge,
\nsegments) evidenced by geothermal areas, recent .. volcanic activity,
\nearthquake swarms, and submarine topographic depressions. Complexities
\nin the fault pattern may be related to a northward decrease
\nin spreading rates along the ridge segment,s. Five new high;
\nquality seismographic stations around the •Gulf of California are
\nnow under construction in order to understand in more detail the
\npattern of sea-floor spreading in this unique, and important region.