137 



All shocks, including aftershocks, from 1934 to April 1955, 

 are shown in Figure 34. The shocks are located to the nearest 

 minute of latitude and longitude, and the qualities on the chart 

 are shown by the varying style of lettering for the magnitude 

 number. 



It is difficult to make definite conclusions about the 

 relationship of esirthquakes to the geological structure of 

 Santa Monica Bay for several reasons; (1) most of the shocks 

 are poorly located (2) statistical studies of the earthquakes 

 are not possible due to the inaccuracies in location, and (3) in 

 most cases, earthquakes do not originate at the surface, but 

 at a depth of several miles. 



Most earthquakes in the California region are associated 

 with faulting. Numerous large faults and countless small faults 

 exist in the vicinity of Santa Monica Bay. The largest and 

 most important fault in the region is the Newport-Inglewood 

 fault zone, which originates in the Santa Monica Mountains 

 near Beverly Hills and continues more or less uninterrupted to 

 Huntington Beach where it goes out to sea. The faulting in 

 this zone is not one major fault, but is composed of numerous 

 short overlapping faults. Other fractures that may be of 

 importance to the geological history of Santa Monica Bay are 

 the Malibu fault and the San Pedro or Palos Verdes fault zone. 

 All of these have been discussed to some extent earlier in 

 this report. 



The Palos Verdes fault zone is known to leave the coast 

 in the vicinity of Redondo Beach, but just what happens to the 

 fault after it reaches the bay is somewhat obscure. Some 



