GREAT EARTHQUAKE OF SEPTEMBER TENTH 



357 



Mountains, two at Carmacks on the Yukon, five at Skagway, several at 

 Juneau, etcetera. Of these after-shocks, those at Dalton House, 90 miles 

 northeast of Yakutat Bay, lasted from 5 to 40 seconds; those at Cape 

 Whitshed, 220 miles west of Yakutat, lasted 100 to 180 seconds. 



THE GREAT EARTHQUAKE OF SEPTEMBER 10, 1899 



General character. — The greatest earthquake of this series began at 

 12.22 p. m., local solar time, in Disenchantment Bay, near Yakutat, or 

 21h. 40m. 13s,, Greenwich mean time.^* It is practically certain that 

 this is the shock in association with which the faulting and changes of 



Figure 4. — Map of Part of Alaska 



Showing minimum area within which the great Yakutat Bay earthquake of September 

 10, 1899, was felt. Stars at phices of known observations 



3* The time of this shock has been variously stated. In earlier papers (Bull. Geol. 

 Soc. Am., vol 17, 1905, p. 31, and Geographical Journal, July, 1906. p. 38) the time has 

 been given as 3 p. m., based on a single statement by a local observer. It has also been 

 stated by men on the ground as 12.15, 12.30, 1.20, 1.30, 1.50, 2 o'clock, etc., their time- 

 pieces varying in relation to solar time. The present figure is computed from the Coast 

 Survey observation near the Copper River delta and distant seismograph records, and 

 may be accepted as correct. 



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