GENER.'\L1ZATI0NS CONCERNING EARTHQUAKES 1^ 



Mexico, notably near Nacosari a few years ago. That 

 well-known site of major shocks in Southern Mexico, 

 the city of Chilpancingo, in the State of Guerrero, is 

 situated in direct continuation with this line. 

 THE TRANSVERSE LINE 



Another line of relatively great seismicity which 

 runs from west to east practically at right angles to 

 the above, approximately along the line of North lati- 

 tude 34°, 30', may be termed the Santa Ynez line. This 

 is chiefly marked by a great fault of corresponding di- 

 rections, which comes on to the land from the ocean 

 near Point Arguello, and continues along the north side 

 of the Santa Ynez Valley as far east as the Topa Topa 

 Mountains. From thence on its course across the Piru 

 wilderness and on eastward has not been traced, but 

 has been inferentially suspected along the Boquet Can- 

 yon Rift and through Rabbit Springs Valley, on the 

 east, where it may be looked for on the Desert side 

 and even on into Arizona. 



THE LINE OF GREATEST SEISMICITY NOT 

 CONFINED TO CALIFORNIA 



It is a mistake to treat of the great fault lines and 

 their associated tremors of the San Andreas, San 

 Jacinto and Transverse zones of seismicity as pecu- 

 liarly Californian, when they belong to great belts of 

 such lines which pass far beyond the borders of our 

 state to the northwest and southeast, the former from 

 some unknown point at the north towards the Aleutian 

 Islands, southeastward into the West Indian regions, 

 and the later from an unknown point in the Pacific 

 Ocean, probably eastward into Arizona or beyond. 



The northern section of the San Andreas zone in 

 California is but the southern continuation of a sub- 



