GENERALIZATIONS CONCERNING EARTHQUAKES 17 



set forth, but that after so following it from the north- 

 west to the northeast end of the San Gabriel Moun- 

 tains near Cajon Pass, it branches therefrom in a still 

 more southeasterly course along the San Jacinto Rift, 

 passing into Mexico near Calexico and Mexicali. 



The combined San Andreas-San Jacinto Rift may 

 now be called the chief path of seismxicity and, so far as 

 the purposes of this paper are concerned, this line 

 will be meant when we speak of the San Andreas 

 earthquake line in general. 



A most important fact about the location of the com- 

 bined San Andreas-San Jacinto Rift in Southern Cali- 

 fornia is that it does not pass near or in dangerous 

 vicinity to Los Angeles at all, but passes widely around, 

 the nearest point being thirty miles distant. It is not 

 just, therefore, to this city to be placed within its zone 

 of danger as has been done. 



The northern section of the San Andreas Rift has 

 attained notoriety for seismicity because the San 

 Francisco earthquake of 1906 occurred along it, and 

 the rift as a whole has been justly or unjustly assigned 

 the reputation of being the line of greatest seismicity 

 in California, along which severe earthquakes have 

 taken place in the past and have been predicted for 

 the future. The reputation of this line located many 

 miles from Los Angeles has even been spread by care- 

 less usage to include Southern California and Los 

 Angeles. 



It was along the northern portion of the greater line 

 that the San Francisco disaster of 1906 occurred. It is 

 alleged that the earth moved a horizontal distance 

 of twenty-one feet in forty seconds, to the northwest 

 on the west side of the fault line and to the southeast 



