EARTHQUAKES IN GEOLOGY 



quake shocks in Iceland, a new warm spring suddenly 

 opened to the accompaniment of loud roaring and 

 whistling, and threw water, steam, and fragments of rock 

 to a height estimated at six hundred feet. The force of 

 the new geyser was, however, soon spent, and ten days 

 later it ceased to flow. Nearly all the Icelandic geysers 

 suffered changes during this earthquake, and the famous 

 Strokkur, which had been born during the earthquake 

 of 1789, suddenly ceased its eruption and came to 

 an end. 



In steep-walled mountain valleys earthquakes nearly 

 always cause landslips, and these may completely block 

 the course of a river. The lake formed in this manner 

 during the great earthquake of January 25th, 1348, in 

 Carinthia destroyed no fewer than seventeen villages, and 

 to-day, nearly six centuries afterwards, the area is a great 

 marsh. After the earthquake near Lake Baikal in Siberia, 

 of which we have spoken and in which the ground sank, 

 the sunken area was soon after invaded by the waters of 

 the lake. Sometimes when the earthquake takes place 

 near the mouth of a great river, the channels of the 

 streams are changed. After the Californian earthquake 

 of 1857 the current of the River Kern was turned up- 

 stream ; and the San Gabriel River left its bed to follow 

 a new course offered to it by an earthquake fissure. After 

 the Japanese earthquake of 1891 a former lake was cut in 

 half by one of the earthquake displacements, and one half 

 of the lake was left high and dry. Near Flagstaff, Arizona, 

 there is an old earthquake crack along which the waters 

 of several rivers which intersect it all disappear down the 



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