巻号一覧
23 巻 (1970)
- 4 号 p. 253-
- 3 号 p. 191-
- 2 号 p. 99-
- 1 号 p. 1-
前身誌
23 巻, 1 号
選択された号の論文の11件中1～11を表示しています
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Rayleigh 波の表小口 雄康, 竹内 均1970 年 23 巻 1 号 p. 1-18
発行日: 1970/04/28
公開日: 2010/03/11
ジャーナル フリーPartial derivatives of Rayleigh wave phase velocity with respect to changes of physical parameters in the Gutenberg model are tabulated over the period range from 5sec to 100sec.
Five partial derivatives, ∂c/∂ρ, ∂c/∂VP·H, ∂c/∂VSV·H, ∂c/∂φ and ∂c/∂η are shown in the tables.
We can calculate the increment of phase velocity, Δc, by knowing changes of the physical parameters Δρ, ΔVP·H, ΔVSV·H, Δφ, Δη and making use of the following formula, Δc=Σ{(∂c/∂ρ)Δρ+(∂c/∂VP·H)ΔVP·H+(∂c/∂VSV·H)ΔVSV·H+(∂c/∂φ)Δφ+(∂c/∂η)Δη}.抄録全体を表示PDF形式でダウンロード (46011K) -
Rayleigh 波の表小口 雄康, 竹内 均1970 年 23 巻 1 号 p. 19-31
発行日: 1970/04/28
公開日: 2010/03/11
ジャーナル フリーPredictions of Reyleigh wave phase velocity for the transversely isotropic CANSD and J-S-01 models are made by using the tables of partial derivatives in the previous paper IV-a.
Departures of the predicted phase verocities from the exact ones are within 0.04km/sec. So, these tables will be usefull for the calculation of Rayleigh wave phase velocity as well as of Love waves for any plausible continental models.抄録全体を表示PDF形式でダウンロード (728K) -
渡辺 邦彦1970 年 23 巻 1 号 p. 32-40
発行日: 1970/04/28
公開日: 2010/03/11
ジャーナル フリーOn February 21, 1968, a large earthquake occurred at Ebino plateau, south-west part of Miyazaki Pref. in Kyushu. Since then, Ebino earthquake swarm had been active for about one year. Abuyama Seis. Obs., Sakurajima Volcano. Obs. and Disast. Prey. Res. Inst. of Kyoto Univ. made the temporary observation at 5 stations. The main results on the nature of the Ebino earthquake swarm are as follows:
1) The epicentral region characteristically changed its shape with time.
2) The aspects of the push-pull distribution of the initial P motions appeared to be nearly the same both in large shocks and microearthquakes, showing the same focal mechanism in both cases. This phenomenon does not seem to vary throughout the whole period of this study.
3) According to the wave-period analysis, we recognized the interesting relation between the location of the epicenter and the _frequency of those shocks. It may be considered that this was caused by the difference of the properties of the crustal rocks in the hypocentral region from those outside the focal area.抄録全体を表示PDF形式でダウンロード (704K) -
島崎 邦彦, 竹内 均1970 年 23 巻 1 号 p. 41-48
発行日: 1970/04/28
公開日: 2010/03/11
ジャーナル フリーThe Chandler wobble can be considered to be a succession of free damped nutations of the earth excited by some unknown causes. Bearing this in mind, we apply a linear filtering theory of multichannel time series to the analysis of polar motions. Designing a 2-channel prediction error operator, we calculate the prediction error time series y1(t) and y2(t) corresponding to the x1(t) and x2(t) terms in polar motions. The occurrence of large earthquakes is well correlative with abrupt changes of the prediction error. To clarify this relation, prediction error changes D(t)=[{y1(t)-y1(t-1)}2+{y2(t)-y2(t-1)2}]1/2 are calculated and shown in Fig. 3. It is suggested that Earthquakes excite the Chandler wobble. In order to confirm this, we must calculate the excitation function from the occurrence mechanism of each earthquake. It will be the subject for a future study.抄録全体を表示PDF形式でダウンロード (459K) -
竹本 修三, 高田 理夫1970 年 23 巻 1 号 p. 49-60
発行日: 1970/04/28
公開日: 2010/03/11
ジャーナル フリーObservational results of far-field residual strains caused by large earthquakes and of permanent deformations in the vicinity of faults associated with destructive earthquakes can be explained well by mathematical models of faulting based on the dislocation theory. But with regard to moderate or small earthquakes, such remarkable phenomena with seismic faulting have not been observed except for a few earthquakes in the California-Nevada region.
Now, strain steps associated with earthquakes ranging in magnitude 3.2 to 5.6 in the northern part of Kinki district have been observed at Iwakura, Amagase and Donzurubo observatories using super-invar-bar extensometers.
The purpose of this paper is to examine whether these strain steps also can be explained by mathematical models based on the dislocation theory.
At the first step, we compared these observed values with the strain field calculated by F. PRESS in 1965.抄録全体を表示PDF形式でダウンロード (930K) -
山岸 登1970 年 23 巻 1 号 p. 61-71
発行日: 1970/04/28
公開日: 2010/03/11
ジャーナル フリーMatsushiro Seismological Observatory, Japan Meteorological Agency.
Ih this paper, the author investigated the relation between the maximum perceptible distance, Δ and magnitude, M, by use of data for Matsushiro Swarm Earthquakes and shallow earthquakes occurred in or near Japan.
According to the result derived from present study, this relation was found to depend on the value of magnitude.
Therefore, the following formulae are useful for estimating the magnitude from maximum perceptible epicentral distance, namely, for Matsushiro Swarm Earthquakes and other earthquakes of M<5.5
M=1.5logΔ+1.6
and for greater earthquakes of M>5.5
M=2.6logΔ-0.8
and for the near shock, the hypocentral distance is rather suitable than epicentral distance.
The reason is as follows;
The attenuation of the maximum trace amplitude with epicentral distance by the same characteristic seismograph depends on the value of magnitude, M, i. e. earthquakes of smaller magnitude are subject to higher attenuation with epicentral distance.抄録全体を表示PDF形式でダウンロード (740K) -
浜口 博之, 長谷川 昭, 笠原 稔1970 年 23 巻 1 号 p. 72-81
発行日: 1970/04/28
公開日: 2010/03/11
ジャーナル フリーA temporary observation of microearthquakes was carried out at Karumai, Iwate Prefecture (40°19′N, 141°32′E) after the occurrence of the Tokachi-oki Earthquake of May 16, 1968. It was made for about 100 days since 22 o'clock on May 18, about 60 hours later than the occurrence of main shock. Total number of observed earthquakes is as many as 52, 000. Most of them were, of course, the aftershocks in usual sense and their hypocenters were located within the aftershock area, of which the areal size is approximately accordant with the Utsu-Seki's law.
Besides these normal aftershocks, however, an activity of microearthquakes with the S-P times less than 5 seconds at the station was clearly observed. These earthquakes, which are evidently located outside of the aftershock area, are the main concern of the present paper. The following natures of these events are found:
a) The time distribution of these events is similar to the normal aftershock activity, and the number of shocks decreases in accordance with the hyperbolic law.
b) The activity for these events is far lower than that of the aftershocks.
c) The region of activity is estimated to lie on the northern part of Morioka-Shirakawa tectonic line, which is about 100km distant from the western boundary of the aftershock area.
A similar phenomenon was reported by KURIHARA and HIKAWA (1968) to occur at the Tokachi-dake Volcano in Hokkaido, although the volcano is far from the aftershock area. A small activity in the northern part of Iwate Prefecture was found at the time of the great Sanriku Earthquake, 1933. This region may be near the place of the present activity. At the time of the Nankaido-oki Earthquake of 1946, activities in the middle part of Kyushu and in Kyoto were also reported. It should be noted that these activities apparently accompanied the great earthquakes and that the excited regions were on the tectonic lines.
From these facts, it is concluded that the effect of a big earthquake is not limited within the so-called aftershock area but the occurrence of big shock sometimes causes the activity in the region far distant from it. It may be reasonable to consider that the microearthquake activity in the present case was resulted by the relative deformation of two crustal blocks of Kitakami mountaineous land and western area, Morioka-Shirakawa line being the boundary of the two blocks.抄録全体を表示PDF形式でダウンロード (863K) -
久保寺 章, 小林 芳正1970 年 23 巻 1 号 p. 82-84
発行日: 1970/04/28
公開日: 2010/03/11
ジャーナル フリーPDF形式でダウンロード (315K) -
竹内 均1970 年 23 巻 1 号 p. 85
発行日: 1970/04/28
公開日: 2010/03/11
ジャーナル フリーPDF形式でダウンロード (111K) -
浜田 和郎, 佐藤 泰夫1970 年 23 巻 1 号 p. 86-88
発行日: 1970/04/28
公開日: 2010/03/11
ジャーナル フリーPDF形式でダウンロード (2232K) -
丸山 卓男1970 年 23 巻 1 号 p. 89-91
発行日: 1970/04/28
公開日: 2010/03/11
ジャーナル フリーPDF形式でダウンロード (205K)
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