 With the San Jacinto Fault Zone to the northwest , the Elsinore fault to the south @-@ southwest , and the Imperial fault centered directly under the Imperial Valley , the area frequently encounters seismic activity , including moderate and damaging earthquakes . Other events in 1852 , 1892 , 1915 , 1940 , 1942 , and 1987 have impacted the region . More small to moderate events of less than 6 @.@ 0 ( local magnitude ) have occurred in this area than any other section of the San Andreas fault system . 
