194 



PHYSIOGRAPHY 



in April, 1905, affected an area of 1,625,000 square miles, and killed 

 about 20,000 people. 



A series of earthquake shocks, lasting from 1811 to 1813, affected 



012 4 6 



Fig. 191. Chart showing the two centers from which the earth waves in the 

 Charleston earthquake spread. The curved lines connect points where 

 the quaking was equally strong. (U. S. Geol. Surv.) 



the Mississippi Valley just below the mouth of the Ohio. Many 

 fissures were formed in the deposits of the flood plain of the Mis- 

 sissippi, and some of them remained open for years. Parts of the 



