JAPANESE EAKTHQUAKES x 



By N. H. Heck 



[With 3 plates] 

 INTRODUCTION 



In these days of global warfare, and in anticipation of a world-wide 

 view in the future, there is need of more geographical and geophysical 

 knowledge. So outstanding a feature as earthquakes in Japan cannot 

 be disregarded. Much has been written on the subject by Japanese 

 seismologists and others, and by two Englishmen — John Milne (1850- 

 1913 ) 2 and, more recently, Charles Davison. 3 Milne, who went to 

 Japan in 1876 to aid in the establishment of that country's new educa- 

 tional system, became interested in earthquakes and began investiga- 

 tions, which were taken up by Omori and others. Many of his 

 writings were based on direct observation; otherwise, nearly all in- 

 formation, including Davison's, is from Japanese sources. Since from 

 Milne's time onward Japan has been treated as an earthquake labora- 

 tory, much material has been published, part of it in foreign lan- 

 guages, and especially in English. 4 However, nowhere is there a brief 

 comprehensive discussion of the principal Japanese earthquakes. 



There is a general impression that Japan is more subject to major 

 earthquakes than any other area of similar extent. Imamura 5 states 

 that there have been 300 great earthquakes during the period of re- 

 corded history. Of these he lists 59 from 1596 to 1935 inclusive, for 

 which statistics and at least partial descriptions are available. Some 

 of the entries may be debatable and some of the statistics may be 

 doubtful, but since they represent all kinds of earthquakes and asso- 

 ciated occurrences they are made the basis for the present discussion 

 and are listed in table 1. 



1 Reprinted by permission from the Bulletin of the Seisniological Society of America, 

 vol. 34, No. 3, July 1944. 



2 See Mrs. Lou Henry Hoover, John Milne, seismologist, Bull. Seism. Soc. Amer., vol. 2, 

 pp. 2-7, 1912. 



"The founders of seismology, Cambridge, England, 1927; The Japanese earthquake of 

 1923, London, 1931 ; Great earthquakes, London, 1936. 



4 In preparing the present paper, I have drawn upon various bulletins of the Imperial 

 Earthquake Investigation Committee, Tokyo, and of the Earthquake Research Institute 

 of Tokyo Imperial University; also The great earthquake of 1923 in Japan (in English), 

 compiled by the Bureau of Social Affairs, Home Office [Tokyo], 1926. 



* Imamura, Theoretical and applied seismology, Tokyo, 1937. 



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