DEVELOPMENT OF SEISMOLOGY IN JAPAN 299 



the barometric data and winds, he attributes the principal part of the 

 secular change thus analysed to the actual upheaval or depression of 

 the crust. According to his results, the secular subsidence has been 

 most remarkable in Kusimoto, Aburatnbo and Hanasaki. These stations 

 lie on the Pacific coast of Central Japan and Hokkaido respectively. 

 On the contrai-y, a conspicuous upheaval has been found at Hososima, 

 situated on the Pacific coast of KyusyCi. An upheaval was shown only 

 in the latter station and at Ivvasaki on the Japan Sea coast, the 

 remaining six stations giving depressions. Besides, it seems that the 

 Japan Sea side and the western side of Kyusyu show generally a less 

 amount of vertical movements, positive or negative. R. Sekiguti, in 

 his discussion of the above results, appended to this paper, computed 

 the secular acceleration of the rate of depression at Aburatubo, the 

 station lying near the origin of the recent great earthquake, and 

 obtained a positive value which is not in accord with the retardation 

 to be expected from the traditional depression of this district. ^^^ 

 Sekiguti also gives a vectorial representation of the 19-year tide, and 

 remarks that the Japan Sea stations form a quite distinct type or 

 group in this respect. 



It need not be remarked that for the njareographic studies of the 

 crustal movements, the careful investigations of the influences of 

 meteorological elements, especially of the barometric pressure and winds 

 are of primary importance. Omori frequently touched on this matter 

 in his papers on allied subjects. Saem. Nakamura^^^ also made some 

 studies on this problem. Kawakami's result has just been cited. 

 S. Ogura*^'^ recently made an elaborate investigation ot the effect of 

 the atmospheric pressure on the sea-level, especially in the island-stations 

 in the western part of the Northern Pacific. Isolated island-stations 

 were chosen in order to make evident the pure pressure effect undis- 

 turbed by winds. The daily mean level was compared with the daily 

 mean pressure, and the pressure- factor as well as the time of retarda- 

 tion was estimated. On the other hand, T. Terada and S. Yamaguti^^^ 

 made an investigation into the combined effect of pressure and wind 

 upon sea level in a few stations, in 1923 and 1924. From the results 



(1) Compare result of Imamura's investigation on the level change at Aburatubo, 

 loc. cit., Ho. lOOA (1925). 



(2) Jap. J. Astr. Geophys., 3 (1925), 115; Kisyozassan, 1 (1918), No. 3. 



(3) Jap. J. Astr. Geophys., 2 (1925,\ 209. 



(4) To be publiohed in Jap. J. Astr. Geophys., 4 (1926). 



