著者
石本 巳四雄 高橋 龍太郎
出版者
東京帝国大学地震研究所
雑誌
東京帝國大學地震研究所彙報 = Bulletin of the Earthquake Research Institute, Tokyo Imperial University (ISSN:00408972)
巻号頁・発行日
vol.8, no.4, pp.427-458, 1930-12-16

Du 14 Fevrier 1930 an 22 Avril de la meme annee, an grand nombre de seismes ont eu lieu dans la region d'Ito, ville d'eaux situee au bord oriental de la presqu'ile d'Idu. Dans le but d'etudier le mouvement de la croute terrestre a l'occasion de ces seismes, on a installe un paire de pendules horizontaux (clinographes de silice fondu, inventees par le Prof. M.Ishimoto) a Ito afin d'observer les variations de l'inclinaison de la surface terrestre; les observations ont etc effectuees a, partir du 12 Mars. De plus, le 19 Mars une installation iclentique a ete faite a Kawana et les deux observations ont ete poursuivies jusqu'au 30 Juiri. La sensibilite du clinographe a Ito etait reglee de facon a donner 1 cm. de deviation pour 1 seconde d'inclinais-on, tandis que la sensibilite du clinographe a Kawana et les deux fois plus grande que celle du clinographe d'Ito. Les clinographes etaient installees dans des caves creusees dans la masse de scorie volcanique.
著者
石本 巳四雄
出版者
東京帝国大学地震研究所
雑誌
東京帝國大學地震研究所彙報 = Bulletin of the Earthquake Research Institute, Tokyo Imperial University (ISSN:00408972)
巻号頁・発行日
vol.13, no.3, pp.592-607, 1935-09-30

Les observations accelerometriques ont etc continuees encore pendant 1934 aux memes stations dans les deux villes. A cette annee nous avons reussi a enregistrer 15 seismes de degree II et 2 seismes de degree III. L'acceleration maxima corresponded a chaque seisme a etc determinee et montree dans le tableau II. D'une part elle est superieur a la partie haute de la ville quand la distance epicentrale reste moins que 50 km. D'autre part la periode predominante dans les secousses sismiques est comparativement petite ii la partie haute de la ville. Nous constatons que la periode predominante corresponde a celle d'oscillation propre de la couche superficielle du terrain et elle a un rapport serre avec des dommages sismiques. De plus, nous avons essaie de trouver quelque relation entre la periode des secousses provoquees artificiellement et la periode predominante dans les secousses sismiques, mais nous n'avons pu constater aucune coincidence entre eux.
著者
石本 巳四雄
出版者
東京帝国大学地震研究所
雑誌
東京帝國大學地震研究所彙報 = Bulletin of the Earthquake Research Institute, Tokyo Imperial University (ISSN:00408972)
巻号頁・発行日
vol.6, pp.127-147, 1929-04-23

Il est certain qu'un grand tremblement dc terre se produit avec accompagnemeiit de changemeiits topographiques: Ics changemciits out ete particuliereinent remarquables Jors des trois dernicrs grands trembleinents de terre surveiius au Japon. Les etudes nous out conduit a considerer que le cliangenieut topographique n'est pas celui qui correspond a des ondes sismiques rayonnaut dans toutes les directions.
著者
石本 巳四雄 飯田 汲事
出版者
東京帝国大学地震研究所
雑誌
東京帝國大學地震研究所彙報 = Bulletin of the Earthquake Research Institute, Tokyo Imperial University (ISSN:00408972)
巻号頁・発行日
vol.14, no.4, pp.534-542, 1936-12-21

Nous avons execute certaines experinces sur le sol, dont la propriete mecanique est connue, avec deux appareils construits dernierement, et obtenu les resultats suivants : 1) La viscosite et l'elasticite du sol changent avec le contenant d'eau : les deux diminuent assez rapidement quand de l'eau augumente.
著者
森本 良平 村井 勇 松田 時彦 中村 一明 恒石 幸正 吉田 鎮男
出版者
東京大学地震研究所
雑誌
東京大學地震研究所彙報 = Bulletin of the Earthquake Research Institute, University of Tokyo (ISSN:00408972)
巻号頁・発行日
vol.44, no.1, pp.423-445, 1966-07-25

Geology of the main seismic area in and around the town of Matsushiro, the northern part of Nagano Prefecture, central Japan, is investigated by field and literature surveys for the better understanding of the earthquake-swarm which is now taking place. The Matsushiro earthquake-swarm started at the beginning of August, 1965. Since then, the local seismicity has become more active with occasional rise and fall.
著者
松田 時彦 有山 智雄
出版者
東京大学地震研究所
雑誌
東京大學地震研究所彙報 = Bulletin of the Earthquake Research Institute, University of Tokyo (ISSN:00408972)
巻号頁・発行日
vol.60, no.2, pp.281-316, 1985-11-08

1984年9月14日の長野県西部地震に伴って,震央の北西約5kmの御岳山の南斜面が崩壊して岩屑流が発生した.その堆積物に対する観察結果を記述した.岩屑流はi)空気を媒質としたなだれ状の流れであった,ii)流下時に王滝川合流点付近より上流では強風を伴い岩屑をしぶき状に周辺にはねとばした(""岩屑しぶき"").iii)堆積物は中・上流部では地形の小起伏に無関係にうすく平行堆積しているが,下流部(堆積域)では,低所にむかって再移勤している.iv)この岩屑流の直後に山体から噴出した地下水によって水を媒質とした土石流が発生した.
著者
松田 時彦
出版者
東京大学地震研究所
雑誌
東京大學地震研究所彙報 = Bulletin of the Earthquake Research Institute, University of Tokyo (ISSN:00408972)
巻号頁・発行日
vol.44, no.3, pp.1179-1212, 1967-01-30

1. 地形的にその存在が推定されていた跡津川断層は,少なくとも庄川-神通川の分水嶺から北東へ常願寺川上流までたしかに存在する.長さ60km以上,部分的にゆるくを彎曲するがほぼ直線状で,その平均走向N60°E,断層面の傾斜はほぼ垂直,断層面上の断層条線はほぼ水平である. 2. この断層線に沿って,古生代の飛騨変成岩類から第四紀の河床堆積物までの地層および隆起小起伏面や段丘面などの地形面が変位している.この断層の変位の向きは多少の垂直成分を伴った右ずれである.この断層が示す変位の水平成分は断層の主部で約3km,垂直成分は,概して北側の相対的隆起でその量は1km以下である.すなわち,この断層は右横ずれ活断層である. 3. 第四紀の地層・地形面は古い時代のものほど大きく変位しているが,それ以前に生じた岩石では,時代が古くなっても変位量はそれ以上増加しない.したがって,現在この断層が示す変位量3kmは第三紀後期以後に生じはじめたと考えられる.数万年前に生成した河岸段丘が20m以上変位しているから,最近の数万年間における平均の変位速度は1~数m/1000年位と考えられる. 4. 段丘の変位や谷の喰違い現象は,この断層が最近地質時代に数十m以下を単位とする小刻みのほゞ同方向の変位を繰返してきたことを示している。また,この断層沿いにみられる断層崖などの断層地形は大地震時に生じる地形によく似ている.これらのことから,この断層の約3000mの変位量は地震時の変位の集積と考えられる.安政5年(1857)の飛騨地震はこの断層の最近の活動の1つと思われる. 5. 断層線上での谷の屈曲・転移のむきは概して右であるが,その量はその断層線から谷頭までの距離の大きな谷ほど大きい.このことは,この断層が活発な右ずれ変位を繰返していること,谷の喰違い地形は変位のむき・量を大略反映していること,谷の古さは断層線よりも上流の部分の長さにほゞ対応していること,を示唆している.このような谷の累進的転位現象の有無・程度は,未知の断層の活動性を知る1つの目安になると思われる.
著者
松田 時彦
出版者
東京大学地震研究所
雑誌
東京大學地震研究所彙報 = Bulletin of the Earthquake Research Institute, University of Tokyo (ISSN:00408972)
巻号頁・発行日
vol.40, no.2, pp.357-369, 1962-11-15

In this paper the crustal structure of the South Fossa Magna region, where a Tertiary geosyncline is developed, is inferred geologically under some assumptions. The method here adopted consists of two steps; 1) preparation of the stratigraphic profiles in every stage of geological devolopment of the region, and 2) modification of the stratigraphic profiles by the subsequent deformation of the crust. 1) Preparation of the stratigraphic profiles. The early Miocene Misaka and the middle to late Miocene Fujikawa series are the main conponents of the nearsurface crust of the region. They vary in thickness in different geological provinces in the region. Their geologic and tectonic maps are shown in Figs. 1 and 2. The pre-Misaka sediments are supposed geologically to have been deposited on the oceanic crust of transitional crust between the main Japanese Islands and the Pacific. These data and assumptions as well as those listed in A) of Table 2 are used for the stratigraphic profiles of the region (Fig. 3). 2) Modification of the stratigraphic profiles. After the deposition of the Misaka series, the following events took place: i) crustal warping with deposition of the Fujikawa series in the downwarping parts and with erosion of the Misaka series in the upwarping parts, ii) intrusions of quartz diorite stocks of the uplifted parts, and iii) formation of the crystalline schist along the southern limb of the Tanzawa upwarping part. (Boulders of the quartz diorite and of the crystalline schists appear in the upper part of the Fujikawa series of the subsiding belts). Until the end of the deposition of the Fujikawa series, the crustal surface was de- formed in a wavy contour as shown in curve s-s of Fig. 4. From the observations of the Tanzawa schist belt, we can assume that the wavy deformation of the crust mentioned above is due to shear fold with the shear plane inclined northward with angle about 70°. Then we get curve b-b in Fig. 4 as the bottom of the crust. Besides, it is assumed that the quartz diorite magma originated due to melting of the crust and the Mohodiscontinuity represents a boundary between two different materials (the basaltic and ultramafic), and that the volume change of the crust through the magmatic process which brought the quartz diorite stocks and through other tectonic process is negligible. Thus, we get Fig. 5 (b) as the crustal structure of the South Fossa Magna at the end of the Fujikawa time. Fig. 5(b) is here proposed as the present status of the region. If the method and data used in this paper are adequate, it is suggested that present Moho-discontinuity lies between the -15 to -20 km level with increasing depth northward. The Moho-discontinuity shows a fairly strong relief (10 km or more), whose troughs and swells correspond to the subsided belts and uplifted belts originated in Miocene. It is also suggested from Figs. 3 and 5 that the quartz diorite magma was generated from the lower crust in 15 to 20 km depth in the orogenetic epoch. The heat sufficient to melt the crust at such a shallow level might have been supplied from the mantle below.
著者
松田 時彦
出版者
東京大学地震研究所
雑誌
東京大學地震研究所彙報 = Bulletin of the Earthquake Research Institute, University of Tokyo (ISSN:00408972)
巻号頁・発行日
vol.45, no.2, pp.537-550, 1967-08-25

松代地震の進展につれて松代町東部に地震断層の性格をもつた横ずれ地割れ群があらわれたので,その地割れ付近および周辺山地の地質を調べた. 1.調査地域内には,変位量数km以上の既存の大断層は存在しない.とくに今回あらわれた横ずれ地割れ群に沿つては,変位量数m程度の既存の小断層も見出せなかつた. 2.今回の地震であらわれた個々の地割れに沿つても,また,地割れ地帯に沿つても,最近地質時代に同様の変位が生じた形跡(地形的証拠)は見出されない. 3.鮮新世中期以降変位したことのない地質断層(滝本東断層)が地割れ帯に近接して存在するが,それに沿つては今回の地震で地割れは1つもあらわれなかった. 4.既存の断層に沿つて,断層性の変位が生じたたしかな例が1つだけみつかつたが,その断層は主な地割れ地帯からはなれているし,断層面のむきも変位のむきも特異である.松代地震における上記1.と2.の事実は,濃尾・北伊豆などの大地震に伴なつた地震断層の場合と全く異なつている.その意味で松代地震では従来いわれたような「古傷(大地質断層)の再活動」という表現は妥当でない.このような特異性と,松代地震が群発型であることを組合せると,大きな活断層が発達しない所(地質区)では群発地震の方が非群発型大地震よりもおこり易いらしいといえる.上記3の事実は,たとえ大断層があつても最近地質時代(この場合鮮新世中期以後)に変位を増加させた形跡のない断層は,今回のような地震の発生やそれに伴う変位に関与しないらしいという例になる.上記4の地震断層は,松代地震による直接の地震断層ではなくて,その周辺に生じた地盤の調整的変位の結果または地塊縁辺部での強い地震動の結果,地塊境界で生じた二次的変位(いわば間接的地震断層)であると思われる.
著者
中村 一明 笠原 慶一 松田 時彦
出版者
東京大学地震研究所
雑誌
地震研究所研究速報
巻号頁・発行日
vol.8, pp.73-90, 1964-09

昭和39年6月16日新潟地震調査概報
著者
松田 時彦 山崎 晴雄 中田 高 今泉 俊文
出版者
東京大学地震研究所
雑誌
東京大學地震研究所彙報 = Bulletin of the Earthquake Research Institute, University of Tokyo (ISSN:00408972)
巻号頁・発行日
vol.55, no.3, pp.795-855, 1981-03-07

The Rikuu earthquake (M = 7. 2) occurred in the Mahiru Mountains in Tohoku district on 31 August 1896. Associated with the earthquake, reverse faults appeared on the surface along the western and the eastern feet of the Mahiru Mountains (Table 1 and Fig. 1), which are known as Senya and Kawafune earthquake faults (YAMASAKI, 1896), respectively. This was the largest on-land surface faulting of reverse fault type among events in historical time in Japan. These surface faults were re-studied.
著者
伊東 七美男
出版者
公益財団法人 史学会
雑誌
史学雑誌 (ISSN:00182478)
巻号頁・発行日
vol.100, no.8, pp.1355-1395,1505-, 1991-08-20 (Released:2017-11-29)

In the naval system in classical Athens, trierarchs used in principle state hulls and sea-going equipment. In prescription, when their services were over, users had to return them in good condition. Those did not do so were recorded in naval documents as a debtor to the State. The object of this treatise is to make clear the actual situation of debts and their collection, and to consider the historical background. In order to attain this aim, naval inscriptions (IGII^2 1604-1632) have been mainly examined. They record details of the administration of the Athenian navy over about 55 years from the 370s to the 320s B.C.. This examination suggests important points in regard to the controlling power of the State over its wealthy citizens and their social power. From an examination of the inscriptions, the following points can be infered. (1)Debts tended to reach long terms, and each debtor was inclined to have plural and long-term debts. This confirms a view generaly pointed out by many scholars; which shows both a tendency to delay repayment of debts and. inactivity of collection in the navy. (2)However, except for the concentrated collection of debts in the first half of 350s., collection seems to have become active at latest after the middle of 340s B.C., this can be thought to have been greatly influenced by external circumstances: formed the preparations at war against Macedon in the second half of 340s, and security of sea trade routes after the battle of Chaeronea, above all measures for corn supply in the face of food crises. (3)The sum of collected money at times reached more than 10 talents. With 10 talents one could supply 26-27 sets of sea-going equipment. Therefore, collections were of considerable importance for consolidating the navy as a facfor to make sea trade active. (4)It is not necessarily clear whether the intensification of collecting debts had a direct relation to the policies of Eubulus and Lykurgus. But at least there is a possibility that their policies had some influence on it. The author concludes from the above that the character of administration of the Athenian navy in the first half of the fourth century B.C. differs significantly from that of the second. And in its background there seems to have been urgent and difficult circumstances : Social War and relations with Macedon and food crises etc.. Only in the face of such situations was debt collection intensified. It also gives an interesting clue to considering the power of the wealthy citizens in those days.
著者
中川 茂樹 鶴岡 弘 川北 優子 酒井 慎一 平田 直
出版者
東京大学地震研究所
雑誌
地震研究所彙報 (ISSN:00408972)
巻号頁・発行日
vol.84, no.2, pp.107-114, 2009

We launched the Special Project for Earthquake Disaster Mitigation in the Metropolitan Tokyo area to obtain high-resolution images of three-dimensional seismic wave velocity and attenuation structures. The core item of this project is a dense seismic array called MeSO-net for making observations in the metropolitan area. MeSO-net consists of 400 seismic stations, from which data are continuously collected at the Data Center at ERI. At the Sub-Center at NIED, data are backed up and integrated with Hi-net data. Seismic data with a sampling rate of 200 Hz are transmitted to the Data Center using ACT protocol. Data from all stations are received at the Data Center at ERI. After checking the quality (including lost packets) of data received, data are automatically processed and archived using the WIN system. This observational network and the Data Center are equipped with several new functions for reliable data transmission and ease of maintenance.
著者
川北 優子 酒井 慎一
出版者
東京大学地震研究所
雑誌
地震研究所彙報 (ISSN:00408972)
巻号頁・発行日
vol.84, no.2, pp.127-139, 2009

The Special Project for Earthquake Disaster Mitigation in the Tokyo Metropolitan Area has been ongoing (2007−2012). Under this project, the Metropolitan Seismic Observation network (MeSO-net), which consists of about 400 observation sites, has been constructed. The correlations of waveform from local and teleseismic events are high because observation sites are deployed at about 2 or 3-km intervals. In addition, the later phase is easily identified although artificial noise is very intense. However, we are attempting to improve quality by characterizing the various types of noise. In the metropolitan area, various human activities are observed that generate noise such as trains, automobiles, aircrafts, factories, and electrical power. These adversely affect our observations. We recognize various types of noise from continuous records. A spectral graph and a spectrogram in each station are useful for characterizing signals and noise. We also discovered a form of system noise obtained from the relationship between sensor and electrical circuit. We named it Aurora Noise. The strength of Aurora Noise was reduced by improving the electrical circuit. Our study will lead to improving the quality of observed data, and contribute to a new assessment of seismic hazard in the Tokyo Metropolitan Area in Japan.
著者
松原 誠 小原 一成
出版者
東京大学地震研究所
雑誌
東京大學地震研究所彙報 = Bulletin of the Earthquake Research Institute, University of Tokyo (ISSN:00408972)
巻号頁・発行日
vol.84, no.4, pp.331-344, 2009

Many researchers have studied the three-dimensinal seismic velocity structure beneath the Kanto region, central Japan using seismic tomography, because the structure is very complicated due to subducting of the Pacific and the Philippine Sea plates beneath the Eurasian plate. The Tokyo metropolitan area is located in the Kanto region. Initially, the subducting Pacific and Philippine Sea plates are imaged with high-velocity zones. With many data, the oceanic crust at the uppermost part of the subducting Philippine Sea plate was imaged clearly. After construction of the NIED Hi-net, the oceanic ocrust of the Pacific plate subducting to depths over 100km was also imaged. A large low-velocity region at depths of 30-50km beneath the central Kanto region in the east-west direction was found by many researchers. The reason for the low-velocity is considered to be the existence of a serpentinied mantle wedge, curling Eurasian crust, and thick oceanic crust of the Philippine Sea plate. A low-velocity zone at depths of 40-70km beneath the eastern Kanto region with north-south direction was also found. The reason for this low-velocity is considered to be the existence of serpentinied mantle wedge and curling Philippine Sea plate. A high-density seismograph network, called MeSO-net, is under construction in this metropolitan region. The results with these data are expected to reveal a more detailed structure beneath the metropolitan area. We review former studies on the velocity structures beneath the Kanto region and note some characteristic structures beneath the Kanto region with results along arrays of MeSO-net.