2021-08-02T15:28:19Zhttps://repository.dl.itc.u-tokyo.ac.jp/oaioai:repository.dl.itc.u-tokyo.ac.jp:000350672021-03-01T21:14:45Z表面層及び局面に伝播する弾性波の分散Dispersion of Elastic Waves propagated on the Surface of Stratified Bodies and on Curved SurfacesSezawa, Katsutada135218453application/pdf地震波が震源から遠ざかるに従て繰替の振動性が増加する傾向は弾性波の分散によって可なり説明出来るが、其には種々の原因がある。この論文では境界面の状況によるものを主として取扱ひ、其を表面の層に起因するものと、表面の曲率によるものとに分類して考へた。The earthquake motion at a distant point from the origin is oscillatory, though it is not necessarily oscillatory in the neighbourhood of the source. The farther the epicentral .distance, the more grows the oscillation. This is due to the fact that a shock is composed of an aggregate of simple harmonic trains of waves, each travelling with different velocity corresponding to its wave length. The proper velocity of each train of waves depends not only on the surface conditions of the solid, but on the physical nature of the medium, such as the effect of gravity or of heterogeneity of elastic and dissipation constants. In this paper- only the former will be dealt with. The investigation of the effect of the surface conditions on the velocity of propagation is limited to two simple cases, namely the effect of surface layers on the propagation of Rayleigh-type waves and the other the propagation of waves on curved surfaces. Although special problems on the propagation of waves on a stratified surface have already been taken up by eminent mathematicians such as Bromwich and Love, yet the general relation between the thickness of the layers and the velocity of waves has not completely been studied. As to the propagation of waves on curved surfaces, it seems that it has not yet been much studied, excepting those on a spherical surface, in spite of its importance. The present investigation consists of two parts : the first part relates to the dispersion of elastic waves on a solid body with surface layers and the second to the waves propagated over a curved surface.departmental bulletin paper東京帝国大学地震研究所1927-09-20application/pdf東京帝國大學地震研究所彙報 = Bulletin of the Earthquake Research Institute, Tokyo Imperial University3118AN0002969900408972https://repository.dl.itc.u-tokyo.ac.jp/record/35067/files/ji0030001.pdfeng