52.Notes on the Origins of Earthquakes.
スポンサーリンク
概要
- 論文の詳細を見る
1) The author has made a theoretical study of the initial motions of dilatational waves generated from a seismic origin, in which the normal pressure on the surface of the spherical cavity can be expressed by the sum of two zonal harmonics P0(cosθ) and P2(cosθ). It is shown that so long as the wave length exceeds the dimension of the focus, we only observe the push and the pull waves according as the single source is the source or the sink, respectively. If the wave length becomes comparable with the diameter of the seimic origin, the displacements of the dilatational waves due to the single source turn out to be of the same order of magnitudes as those due to the quadruple source, so that we observe both pull and push waves. 2) It is shown that it is not unreasonable to assume that the mechanisms above stated can be applied to the origins in the case of actual earthquakes. If so, then in order to be consistent with the observed distributions of the initial motions, we shall have to assume that the dimensions of the seismic origins are comparable with the wave lengths of the seismic waves radiated from these origins. Our next object for study should be the polarizations in the propagations of very short seismic waves that accompany earthquake sounds, and which cause anomalies in the distributions of the felt areas, owing probably to the short wave lengths compared with the dimensions of the seismic origins. Finally, the author's cordial thanks are due to Prof. M. Ishimoto, Prof. K. Sezawa, Dr. N. Nasu, Dr. G. Nishimura, Prof. F. Kishinouye, and Prof. R. Takahasi for their kind advices.1. 石本所長はその｢地震初動方向分布より震源に四重源の推定｣ なるエポツクメイキングの論文中に於て,初動方向の分布は帯球函數のP0(cosθ)とP2(cosθ)の和で現はし得る事を示されてゐる.然し此の初動方向分布から電源の發震機構は一義的には定まらぬものである.
- 東京帝国大学地震研究所,Earthquake Research Institute, Tokyo Imperial University,Earthquake Research Institute.の論文
- 1936-12-21
東京帝国大学地震研究所,Earthquake Research Institute, Tokyo Imperial University,Earthquake Research Institute. | 論文
- 26.Geophysical Studies of Volcano Miham, Oosima Island; Topographic Survey of the Crater of Mihara and the Magnetic Survey of Oosima.
- 63.Geophysical Studies of Volcano Mihara, Oosima Island : the General Aspect of Physical Conditions in the Crater.
- 43.Some Physical Properties of the Lava of Volcanoes Asarna and Mihara. : I. Electric Conductivity and Its Temperature-Coefficient.
- 39.On the Elastic Waves due to Pressure Variation on the Inner Surface of a Spherical Cavity in an Elastic Solid.
- 25.The Vibration due to Obliquely Incident Waves of a Surface Stratum Adhering Closely to the Subjacent Medium, and the Properties of its Resonance Condition.