The geological investigation of the Neodani earthquake fault clearly came into view at the occasion of the Nobi earthquake in 1891 was the first contribution to the younger tectonics in Japan (KOTO 1893). Immediately after this earthquake, the Imperial Earthquake Investigation Committee was organized. The Kanto earthquake of September 1923, which severely attacked the hearty region of Japan including the cities of Tokyo and Yokohama, called forth the mind of Japanese geologists and geographers the importance of the stratigraphical and tectonic studies in the lowland areas. The Earthquake Research Institute of the University of Tokyo was thus established for the purpose of all scientific investigations on the earthquake problems including geotectonics.
The development of the neotectonic researches in Japan since 1923 would be divided into the following three stages.
The first stage (1923-1945)-The age of the “embryonal” researches on the neotectonics, or the age of the descriptive researches. Many researches especially on the apparent or locational relations between earthquakes, geomorphology and geology were discussed. and published. Among them nearly all of the living or recent problems in progress during later stages were found, though only fragmentally or not substantially. These studies are as follows: The conception of the Kanto structural basin (YABE 1925, YABE & AOKI 1927, AOKI & TAYAMA 1930); drowned valley and the latest land connection (YABE 1929); the conception of tilted blocks with active faults (YAMASAKI 1925, 1927); relation between geomorphology and tectonics (YAMASAKI & TADA 1927, TADA 1929); distribution of geomorphologically distinct faults (TSUJIMURA 1923, 1926); elevation of raised beaches and river terraces in connection with tectonics (IMAMURA 1928, 1932, 1933); Pleistocene stratigraphy and tectonics in Kinki district (NAKAMURA 1930, 1933, 1934, TAKEYAMA 1933, IKEBE 1933, UEJI 1936); geomorphic development and neotectonics based on the detailed stratigraphy (OTUKA 1931, 1933, 1939, 1948); deformation measured by precise levelling (Earthquake Research Institute 1927-); measurement of amount of strike-slip dislocation of the Tanna fault (KUNO 1936); Quaternary movement of the Median tectonic line of SW. Japan (KAWADA 1939, KOBAYASHI 1941).
Among above-mentioned, there were many neotectonically important or suggestive conceptions or data to be expected of more detailed study. However, under the severe circumstance of the unfortunate war, many research works were obliged to interrupt.
The second stage (1946-1955)-“A phoenix stage” or the age of new development after the war. After the demobilization, revival of academic works had immediately performed by the researchers of the preceeding stage. Moreover, younger researchers educated during or after the war, had taken the place of the above-mentioned workers in the neotectonic circle of science.
The Nankaido earthquake in 1946 had served as a moment to the revival of geosciences in Japan (NAGATA 1947, WATANABE 1948). Several flood disasters caused by typhoons had stimulated the investigations on the geomorphology and geology of alluvial lowland areas, especially by using airphotographs (NAKANO 1954, MINATO et al 1950, 1953). SUGIMURA and NARUSE (1954, 1955) discussed the relation between the eustatic and crustal movements. SUGIMURA (1952), succeeding OTUKA's works, realized the parellelism of the active folding measured by the height distribution of river terraces to the structure of the basement Neogene formations. MACHIDA and OKURA (OTA) (MACHIDA 1948, 1951, OKURA 1953, 1958, OTA 1964) tried to realize the characteristics of neotectonic movement from the analytical studies of river and coast terrace deposits. Age of the Pleistocene glaciation in the central mountains in Japan were discussed by KOBAYASHI and SHIKAMA in 1949.
