382 



L. MARTIN ^ALASKAN EARTHQUAKES OF 1899 



llie great Earthquake of September 10, 1899 



Place of observation. 



Commeiioe- 

 ment of 



preliminary- 

 tremors. 



Maximum. 



Amplitude in milli- 

 meters or seconds 

 of arc. 



Total duration. 



Yakutat (Disenchant- 

 ment) Bay. 



Cape W h i t s h e d , 

 Alaska. 



Atlin British Colum- 



h. m. s. 



21 40 13 » 



21 42 11 



21 39 20 



21 40 



" Splendid s 

 lost in the 



20 42 14 



21 1.6 

 21 23.0 



21 3.9 



22 0.0 



21 56.8 



22 14 



h. m. s. 





h. m. s. 















bia. 

 Eau'le Alaska 









Victoria, British Co- 

 lumbia. 

 Toronto, Canada 



Kew, England 



Shide, England 



San Fernando, Spain.. 

 Bombay (Colaba), 

 India. 



Batavia, Java 



Cordoba, Ary^entina. . . 



eismogram 

 mails." 

 22 3 6 



22 20.21^ 

 22 23.5 

 22 24.9 

 22 38 9 



22 56.3 



23 2.8 



23 1 ^-2 

 ^-^ I 15.0 



r 0.4 1 



1 42 

 23^ 9.1 

 1 13.3 i 

 121.5 J 



" Over an inch." 



Vibrations across 



paper. 

 10.8 inches 



5 36 55 

 3 



14.62 inches.. 



1.78 inches 



4 11.8 



9.3 inches 



5 millimeters . . . . 



2 11 



Mauritius, Indian) 

 Ocean. " / 



1.47 inches 





1.44 inches 





Capetown, South Af- ) 

 rica. 1 



2.4 inches 



3 30 



a The apparent anomaly of the shock being felt at Toronto, etcetera, before 

 it was recorded at the origin is probably due to the fact that the extremely 

 delicate first movements which separate into the preliminary tremors were 

 well started on the way before the more severe motion, perceptible to the 

 senses of persons nearer the origin, was recorded. Doctor Oldham computes 

 this same origin as 21h. 39m. 30s. 



b First maximum, 22h. 20.21m. 

 Second maximum, 22h. 25.6m. 



cAir tremors marked beginning and end. 



MAGNETOGRAPH RECORDS 



Instruments for the measurement of terrestrial magnetism also re- 

 corded the Yakutat Bay earthquakes. The optical registration and the 

 accurate time observation make these valuable as earthquake records. So 

 far as reported, the magnetographs recorded these shocks at Toronto, 

 Canada ;^^ Utrecht, Holland, and Wilhelmshaven, Germany, but not at 



98 Fifth Report of the Seismological Committee of the British Association for the Ad- 

 vancement of Science, 1900, p. 83. 



