44 SOUTHERN CALIFORNIA GEOLOGY 



ern California in 1906, another snap was soon clue 

 here, owing to the "accumulation of strain." 



Arguments were presented at some length to show 

 that such a shock could not take place north of San 

 Francisco along this line of seismicity (which extends 

 in that direction to the Arctic Circle) ; arguments 

 which have been thoroughly refuted by the major 

 quake which took place in the sea off the Alaska Coast, 

 October 24, 1927. 



If the seismic snaps, or releases, are to take place 

 alternately between the northern and the southern 

 ends of the San Andreas alleged line of greater seis- 

 micity according to Dr. Willis' theory, and the next 

 one is to take place to the south, why should the lat- 

 ter necessarily take place in Southern California, which 

 embraces only one hundred and fifty of the two thou- 

 sand miles along which the line extends in that south- 

 erly direction? 



It is like sitting in the main offices of the great South- 

 ern Pacific Railway System in San Francisco and pro- 

 phesying where the next spike will loosen or the next 

 train will be derailed along its thousands of miles of 

 track. Especially does it now seem absurd since the 

 recent, major shocks of 1927 off the coast of Alaska, 

 at Lompoc and in the Cholume Valley. 



Since the collapse of the former, mountain-movement 

 theories, as explained on another page, there are no 

 data to establish the theory that such alternations of 

 occurrences might take place in California. 



In order to arrive at laws of alternations, periodicity 

 and recurrence of shocks along this line we must 

 not only consider the insufficient history of earth- 

 quake occurrences in California, but their occur- 



