MAGNETIC SURVEY OF JAPAN FOR THE EPOCH 1895.0. 171 



Fig:. 15. 



The disturbance of the vertical field at the epicenter is 



2.06 X 10'' 

 1918" X 10'" =-Q56 C.G.S. unit upward. 



or if we take the image to vary as the cube of the distance of 

 the stations 



1.16xlO-"xl918xlO^ = .022 C.G.S. unit upward. 



From the five Austro- ^ 



Hungarian stations only, we get | / 



the epicenter at 



Longitude 7.°3 E, 

 Latitude 57.°9 N. 



The mean value of m is 

 .732x10^5 C.G.S. unit at a 

 mean depth of 1328 kilometers, 

 giving disturbance at the epi- 

 center .042 or .014 C.G.S. 

 units upward, according as the 

 strength of the image is taken 

 to be constant or to vary as 

 the cube of distance of stations. 



The four British stations 

 give epicenter at 



Longitude 16.°6 W. Latitude 73.°3 K 



The mean of five values of image is 4.02 x 10^^ C.G.S. at a mean 

 depth of 2634 kilometers, giving vertical disturbance at the epicen- 

 ter .058 or .033 C.G.S. units upward, according as the strength of 

 the image is taken to be constant, or to vary as the cube of dis- 

 tance of stations. 



