SUMMARY OF CONCLUSIONS 229 



tion was made that the next shock would take place 

 in Southern California, and, inferentially, at Los An- 

 geles. One occurred in the sea off Alaska and two 

 in Northern California. One of the latter was along 

 the northern section of the San Andreas Rift in the 

 Cholume Valley of San Benito County, and the other 

 was along the Santa Ynez Rift, near Lompoc. All of 

 these were shocks of relatively great severity and of 

 the kind predicted to next occur in Southern California. 

 Each was far north of Los Angeles. 



The records of seismic disturbances that have taken 

 place in Southern California in times past are incom- 

 plete and unsatisfactory, inasmuch as they omit on the 

 one hand the mention of many shocks that have taken 

 place and on the other hand greatly exaggerate the 

 intensities of those that have taken place. They are 

 certainly not sufficient to permit deductions, as have 

 been attempted, concerning periodicity or future 

 severity. 



The geology of Southern California shows that the 

 great stresses and strain of the movements have been 

 largely relieved in past times. There is no scientific 

 reason for the anticipation of greater shocks in the 

 future than have occurred within the memory of man. 

 Southern California is a region in which the fractures 

 are broadly distributed, so that intense accumulations 

 and releases of strain are not so strongly probable as 

 where the fractures are closely spaced, as along the 

 Northern California coast. Likewise, the region is one 

 where long accumulations of strain are probably pre- 

 vented by frequent, slight releases. 



Without admitting that any fault line is ever a 

 dead one, I have shown that most of the great 



