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Volume 8, Issue 3
Displaying 1-7 of 7 articles from this issue
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Two Dimensional CaseRyosuke SATO1956 Volume 8 Issue 3 Pages 121-137
Published: March 30, 1956
Released on J-STAGE: March 11, 2010
JOURNAL FREE ACCESSWhen elastic waves are incident to a rough surface, we must take some other disturbances in consideration in addition to regularly reflected waves (which are first approximations), in order to satisfy the boundary conditions at the free surface. In this paper, we investigated only Rayleigh waves of these excited waves when the incident waves has the form of a unit function, assuming the slope and the magnitude of the roughness small compared with the wave-length of the incident waves, which is reasonable in seismology. The main results are as follows;
(1) The Rayleigh-pulses appear in the direction of propagation of incident pulse (positive direction) and in the opposite direction (negative).
(2) These pulses are confined to the very neighbourhood of surface.
(3) The Rayleigh-pulses are generally larger in the positive direction than in the negative direction, and especially, when SV-waves are incident at an angle φ (which is larger than the critical angle), this pulse is very large in comparison with ones for the other angles of incidence.
(4) The larger is the angle of incidence, the shaper is the Rayleigh-pulse in the positive direction, but ones in the negative direction become more blunt.
(5) These pulses are excited by normal incident pulse but do not appear in the case of tangential incidence.View full abstractDownload PDF (1029K) -
Kyozi TAZIME1956 Volume 8 Issue 3 Pages 138-148
Published: March 30, 1956
Released on J-STAGE: March 11, 2010
JOURNAL FREE ACCESSAt first the practical method for eliminating the coupling effect was proposed. Next the new expression for the magnification was obtained. Then a systematic design was discussed in conformity with the above considerations. Some of the old erroneous ideas were also pointed out.View full abstractDownload PDF (778K) -
Yasuo SATÔ1956 Volume 8 Issue 3 Pages 149-154
Published: March 30, 1956
Released on J-STAGE: March 11, 2010
JOURNAL FREE ACCESSDirection of the earthquake sound was considered.
First, we denote the position of the origin O, and the observation point S. Assume that the earthquake sound was heard from the direction of X at the point S, and put φ=∠OSX (See Fig. 21). If the number of reports that give ∠OSX between φ and φ+Δφ is F(φ) Δφ, the function F(φ) is the frequency function that indicates the direction characteristic of earthquake sound, and we call the graph of F(φ) in polar coordinate as “frequency diagram”.
It seems that the frequency diagram has the following properties.
1) F(φ) has a maximum near φ=0.
2) F(φ) sometimes has a small maximum near φ=180°.
3) Frequency diagram has a form like a leaf.
4) Its shape is similar to the direction characteristic of some kind of an antenna.
5) The direction of the earthquake sound coincides with that of the epicentre. Or in other words, we may say that the direction of the earthquake sound coincides with that of the hypocentre in some meaning.
6) Therefore, there is some possibility that we can utilize the frequency diagram for the determination of the origin.View full abstractDownload PDF (441K) -
Kyozi TAZIME1956 Volume 8 Issue 3 Pages 155-157
Published: March 30, 1956
Released on J-STAGE: March 11, 2010
JOURNAL FREE ACCESSDownload PDF (264K) -
Takeshi MIKUMO1956 Volume 8 Issue 3 Pages 157-160
Published: March 30, 1956
Released on J-STAGE: March 11, 2010
JOURNAL FREE ACCESSDownload PDF (408K) -
Kazuo HOSHINO1956 Volume 8 Issue 3 Pages 160-162
Published: March 30, 1956
Released on J-STAGE: March 11, 2010
JOURNAL FREE ACCESSDownload PDF (270K) -
Haruo MIKI1956 Volume 8 Issue 3 Pages 162-164
Published: March 30, 1956
Released on J-STAGE: March 11, 2010
JOURNAL FREE ACCESSDownload PDF (270K)
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