The first order triangulation stations are set every 40 to 50km all over the Japanese islands. Those stations in the northeast part of Honshu surveyed in around 1898, 1962 and 1979 were analyzed in the paper. Based on the data of horizontal displacements of the neighboring three triangular stations, the divergence, rotation, maximum shear, and the direction and magnitude of principal strain axes in the triangle are calculated. The bench marks of the first-order leveling set along the main roads in the Japanese islands has been surveyed every tens years, and those data are compared with the horizontal movements. Based on the pattern of horizontal movements, the area is divided into the north, and south parts separated by the central part running in NW-SE direction from Sendai to Sakata via Yamagata, Shinjo and Yokote. In the first term (1898-1962), the north part shows extension in triangulation and upheaval in leveling in general. The south part shows contraction in triangulation and subsidence in leveling. In the central part contraction and extension parts are intermingled. In the second term (1962-1979), those movements were reversed, but the boundaries have not changed so much. Thus the analyses show that the area of expansion is correlated with the upheaval, and the area of contraction with the subsidence in general, and those horizontal and vertical movements are reversed in every tens years just like pulsation. Destructive earthquakes tend to take place in the areas greater than 10_-5 in maximum shear, where the contours of divergence run thickly. The both principal axes tend to be the extension in the upheaval areas, and the contraction in the subsidence areas. The authors think that such crustal movement must not be due to external forces but be due to the internal expansion and contraction.
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