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