THE 



POPULAR SCIENCE 



MONTHLY 



MAY, 1907 



THE JAMAICA EARTHQUAKE 1 



By Professor CHARLES W. BROWN 



BROWN UNIVERSITY 



TTT ITHIN nine months three regions in the western hemisphere, 

 * * geologically closely akin but geographically distant one from 

 the other, have been visited by earthquakes, causing an appalling loss 

 of life and property. In all cases the disasters have been preceded by 

 minor earth-shakings for years, and the areas were known to be in 

 zones of earth-unrest. No warning, however, unless the tremors that 

 occur at irregular intervals every month or two could be counted as 

 such, has characterized these last disturbances. But these tremors must 

 be regarded as the climax of a long-continued yielding to strain which 

 has resulted in a series of minor breakings. This faulting culminated 

 in a great fracturing of the earth's crust and a consequent destructive 

 earth-shaking. The kindred conditions of these different areas appear 

 to be, first, a considerable amount of differential relief only obtained 

 where mountains are associated with marine depths ; and, in the second 

 place, where newer and less compacted sediments occur upon these 

 slopes. 



For several months previous to the afternoon of January 14, 1907, 

 there had been no noticeable increase in the number or intensity of the 

 customary slight shocks that occur in the Island of Jamaica every 

 month or two. In Weather Eeport IV. of Jamaica, Mr. Maxwell Hall 



1 The writer desires to acknowledge his indebtedness to Dr. Charles D. 

 Walcott, formerly director of the U. S. Geological Survey, and to J. D'Aeth, 

 assistant director of Public \Vorks; Mr. Maxwell Hall, resident magistrate; 

 Mr. Charlton Thompson, harbor master, and to many other official and private 

 citizens of Jamaica for their cordial cooperation and aid in the prosecution 

 of the investigation. 



vol. i,xx. — 2 r ) 



