SOME LOCAL EFFECTS OF THE SAN FRANCISCO 

 EARTHQUAKE 



STEPHEN TABER 

 Leland Stanford Junior University 



■ The principal damage done by the San Francisco earthquake 

 of April 1 8, 1906, was confined to a long, narrow area extending 

 along the Pacific coast in a northwest-and-southeast direction, with 

 the city of San Francisco near its center. The area in which the 

 greatest damage was done is a little over 200 miles in length and 

 scarcely 40 miles in width. The earthquake may be accounted 

 for by the geological structure. The principal valleys of California 

 have been formed by a system of parallel faults running in a general 

 northwest-and-southeast direction, and the disturbance occurred 

 along one of these old fault-lines. 



The particular fault which caused the earthquake is the Stevens 

 Creek fault; it has been traced across the Santa Cruz quadrangle 

 by Dr. J. C. Branner and Dr. J. F. Newsom, and is described by 

 them in the unpublished Santa Cruz folio of the United States Geo- 

 logical Survey. It runs from Crystal Springs Lake through Woodside 

 and the Portola Valley, over the saddle that joins Black Mountain 

 v/ith the crest of the Santa Cruz Range, down the Stevens Creek 

 canyon, crosses Campbell Creek about 2 miles southwest of Sara- 

 toga and continues in the same southeasterly direction toward 

 Loma Prieta. From Crystal Springs Lake the fault has been traced 

 toward the northwest by Professor A. C. Lawson through San Andreas 

 Lake and out into the ocean near Mussel Rock, about 7 miles scuth 

 of the Cliff House at San Francisco. 



The topography appears to indicate that the fault-hne continues 

 its northwesterly course through Bolinas Bay and Tomales Bay, 

 and that it finally leaves the coast near Point Arena in Mendocino 

 County. 



The present paper deals only with the movements that took place 

 along this fault-line between Crystal Springs Lake and Black Mcun- 



3°3 



