212 



MOVEMENTS AND DEFORMATIONS 



Fig. 212. Map showing in black the principal earthquake regions of the Old 

 World. (Montessus de Ballore.) 



Surface changes. During the passage of notable earthquake 

 waves the solid rock may be fractured, though the fractures are 

 rarely observable at the surface where the rock is covered by deep 

 soil. In a few instances, surface-rock has been seen to be thorough- 

 ly shattered by the passage of an earthquake, as in the Concepcion 

 earthquake of 1835. Joints which were closed before, may be 

 opened during an earthquake. Thus in northern Arizona, not far 

 from Canyon Diablo, there is a crevice traceable for a considerable 

 distance which is said to have been opened during an earthquake 

 (Fig. 214). Locally, it gapes several feet. During an earthquake 

 which shook the South Island of New Zealand in 1848, "a fissure 



