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JOUIiNAL OF THE COLLEGE OF SCIENCE. TOKYO IMPERIAL tTNIVERSITT. \}~' . 



VOL. XLIV., ART. 6. 





On Some Remarkable Relations between the Yearly 



Variations of Terrestrial Phenomena and 



Solar Activities. 



By 

 Torahiko TeRADA, 



With 17 text figures. 



I. Frequency of Earthquakes. 



Id a previous communication! it was shown that the distri- 

 bution of the barometric pressure in our region is apparently in- 

 fluenced, not only by the total area of faculse passing the central 

 meridian of the sun's disc, but also by the difïerence of the areas of 

 those situated on the northern and southern solar hemispheres re- 

 spectively. On the other hand, the present author has been long 

 since engaged with the investigation of the barometric gradient as 

 one of the important secondary causes determining the seismic fre- 

 quency and already published some results obtained^\ If the solar 

 activities afïect the barometric condition to a sensible degree, we 

 will not be surprised, if they also would show some correlations 

 with the frequency of occurrence of earthquakes. As a first step 

 for testing this idea, the yearly frequency of earthquakes observed 

 in different Japanese stations, were compared with the areas of 

 sunspots and faculse for an interval of thirty years, 1886-1916. 



1) Japanese Journal of Astronomy and Geophysics, 1 (1922), No. 2 ; also in Papers 

 dedicated to Prof. H. Nagaoka to commemorate the twenty-fifth anniversary of his professor- 

 ship. 



2) Proc. Tokyo Phys.-Math. Soc, [1] 5, p. 454. See also H. Nagaoka, ibid. 6, p. 208; K. 

 Hasegawa, ibid. 7, p. 181 ; Saem. îsakamura, ibid. 8, p. 69 ; T. Terada and S. Masuzawa, ibid. [2] 

 1, p. 343. 



