EARTHQUAKES IN GEOLOGY 



many objects fell down, and it was as if the ship were 

 grounding on a reef." Another report from a locality 

 not far from this speaks of a strange submarine noise not 

 unlike distant thunder, or still more like the distant 

 firing of heavy guns. At the same time there was a 

 vibration of the ship as though the anchor had been 

 let go. 



The foregoing are representative of the large majority 

 of the reports of seaquakes. The ship quivers, vibrates ; 

 loose objects clatter and tumble. There is a strange 

 thunderous noise in the sea. The first impression is as 

 if the ship were grinding upon the bottom, and there is 

 an instinctive rush of the crew to the deck to see if the 

 ship is not on a reef. In some instances there are some 

 forcible disturbances. M. Vulet d'Aourst speaks of a 

 seaquake so severe that " the Admiral feared the com- 

 plete destruction of the corvette. 1 ' Heavy objects, 

 including cannon and their carriages, were thrown upon 

 the deck. The ship itself seemed to be hurled up- 

 wards. 



One of the explanations offered of a phenomenon such 

 as the last described is that the vessel has been near a 

 submarine volcanic eruption of great power. The places 

 where some or most of the seaquakes have been observed 

 have been charted, and certain districts of the ocean have 

 been found to produce more of these disturbances than 

 others. Among the first to be thus determined were two, 

 located in the Atlantic Ocean, very near the Equator 

 and nearly midway between Cape Palmas on the south- 

 eastern coast of Liberia and Cape St. Roque, Brazil. 



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