28o 



PHYSICAL GEOLOGY 



extends from Spain through the Himalayas to eastern China and 

 from which 53 per cent, of the recorded earthquakes originated ; and 

 the Pacific belt, which borders the Pacific Ocean and from which 

 41 per cent, of the recorded earthquakes came. Only 6 per cent, of 

 the recorded earthquakes have occurred outside of these two belts, 

 showing how rare severe earthquakes are over the greater portion 



Fig. 279. — Earthquake regions of the Western Hemisphere, shown in black. 

 (After Montessus de Ballore.) 



of the globe. The earthquake zones are shown in Figs. 278 and 279. 

 It should not be concluded from the above that all parts of the earth- 

 quake belts are equally affected. For example, along the line of the 

 proposed Nicaraguan interoceanic canal, earthquake shocks are 

 frequent and severe, while along that of the Panama Canal they have 

 been few and slight, as is shown by fragile arches which have re- 

 mained standing for many years. 



