On the Proper Oscillations of the Surface Layer and the Area of Abnormal Intensity

[摘要] By applying Takahashi's method the present author analysed the proper oscillation of the surface layer in Tokyo. Moreover he analysed the coda X, which appears in case of the deep seated earthquake, and discussed the reflection waves from the discontinuous layer. If we assume that the seismic waves travels perpendicularly to the discontinuous layer, there should occur several reflection waves and the interval T of their waves is given by the following relation: T=2H/V where H is the depth of discontinuous layer, V the velocity of S wave. From this relation we calculated the depth of layer and obtained approximately the value as 45km and it is found that the depth of the discontinuous layer in the region of abnormal intensity seems smaller than that in the normal region. From this relation we can explain qualitatively the several characteristics of the area of abnormal intensity.

[学科分类] 大气科学