著者

羽鳥 徳太郎

出版者

東京大学地震研究所

雑誌

東京大学地震研究所彙報 (ISSN:00408972)

巻号頁・発行日

vol.58, no.2, pp.433-437, 1983-10-22

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1982年12月28日三宅島近海に発生した群発地震で,八丈島八重根検潮所において全振幅40cmの小津波が観測された.しかし,それ以外の伊豆諸島の検潮記録では風浪による顕著な副振動と重なり,津波は検知できなかった.

著者

羽鳥 徳太郎

出版者

公益社団法人 日本地震学会

雑誌

地震 第2輯 (ISSN:00371114)

巻号頁・発行日

vol.42, no.4, pp.467-473, 1989-12-24 (Released:2010-03-11)

参考文献数

33

被引用文献数

3

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The Pacific coast of Japan has often suffered severe damage by distant tsunamis propagated from the circum Pacific regions (Chile-Peru, Kurile-Kamchatka and Aleutian-Alaska). Based on the historical documents or tide-gauge records observed in Japan during the period of about 400 years, 1586-1988, the geographic distribution of cumulative tsunami energy, ∑H2 for each 150km segment along the coast is investigated. The energy distribution for the distant tsunamis is compared with that of the near tsunamis which were generated in the vicinity of Japan. The obtained results are as follows:1) The amount of cumulative energy, ∑H2=51m2 from the Chile-Peru tsunamis is largest at the Sanriku region, northeastern Japan.2) The tsunami energy from the Kurile-Kamchatka reaching East Hokkaido and Sanriku regions is large, but the amount of energy is about one-third of that of the Chile-Peru tsunamis.3) The energy from the Aleutian-Alaska and Philippine-Indonesia tsunamis is relatively small because of the effect of directivity.4) The pattern of energy distribution for the distant tsunamis is different from that for the near tsunamis generated around Japan. Percentage of the energy from the distant tsunamis reaching SW. Hokkaido, Fukushima, Ibaraki and Okinawa is about 50% of the total tsunamigenic energy.

著者

羽鳥 徳太郎 相田 勇 岩崎 伸一 日比谷 紀之

出版者

東京大学地震研究所

雑誌

東京大学地震研究所彙報 (ISSN:00408972)

巻号頁・発行日

vol.56, no.1, pp.245-263, 1981-08-31

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Owase located on the east side of Kii Peninsula has been hit by many tsunamis. Sources of most tsunamis were off Tokaido along the Nankai Trough. The 1960 Chile tsunami that propagated across the Pacific Ocean also hit Owase City. There remain even now traces of the inundated level on many houses in Owase caused by the 1944 Tonankai and 1960 Chile tsunamis. Based on these traces, the inundation heights of the two tsunamis run-up on land were surveyed, using the automatic level from Nov. 4 to 7, 1980. The relation between the geographical distribution of the inundation heights and the damage to houses was investigated. The results of the present surveys are as follows: 1) The inundation heights of the 1944 Tonankai tsunami at the harbor were 5.0-5.5 m above M.S.L. Ground about 3.0 m above M.S.L. was inundated. The inundated area stretched along the Kita River. The water level decreased in height as it moved inland. The topography of the ground controls the damage to houses. Fifty percent of the ordinary Japanese wooden type houses were damaged when the water reached 1.5 m above the ground. From the inclination of the water surface along the Kita River, the mean water velocity is calculated as 3.5 m/sec. 2) The inundation heights of the 1960 Chile tsunami at the harbor were 3.0-3.5 m above M.S.L. Although the water reached 1.0-1.5 m above the ground, hardly any houses were washed away. The traces of the inundated level into land are nearly flat, suggesting that the velocity of the incident flow was small. 3) Based on old documents, the inundation height of the Ansei Tokai tsunami (Dec. 23, 1854) is estimated as 6.5 m above M. S. L. The heignt is 0.7-1 m higher than that of the 1944 Tonankai tsunami. Ground above 4 m high was inundated.

著者

高橋 龍太郎 羽鳥 徳太郎

出版者

東京大学地震研究所

雑誌

東京大学地震研究所彙報 (ISSN:00408972)

巻号頁・発行日

vol.39, no.3, pp.561-577, 1961-12-15

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At 3 h 10m 59.1s (J.S.T.), Feb. 27, 1961, there occurred a remstrong earthquake off the south-east coast of Kyushu, Japan. According to the Japan Meteorological Agency (JMA), the magnitude of the earthquake was 7.2, depth 17km and the position of the epicenter 31°.7 N, 131°.7E. Accompanying this earthquake, a moderate tsunami was observed on the coasts of Kyushu and Shikoku.

著者

相田 勇 梶浦 欣二郎 羽鳥 徳太郎 桃井 高夫

出版者

東京大学地震研究所

雑誌

東京大学地震研究所彙報 (ISSN:00408972)

巻号頁・発行日

vol.42, no.4, pp.741-780, 1965-03-15

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A tsunami accompanying the Niigata Earthquake of June 16, 1964 is described on the basis of mareograms collected in the vicinity of the source area and a field survey, carriedout immediately after the earthquake by the members of the Earthquake Research Institute, along the coast of the Japan Sea from Akita to Naoetsu. The generating area of the tsunami, estimated by means of an inverse travel chart of the wave front based on the arrival time of the initial motion of the tsunami to the coastal station, is located in the sea on the continental shelf, extending about 90km in an elongated shape roughly parallel to the coast line from the northern part of Niigata Prefecture to Yamagata Prefecture.

著者

羽鳥 徳太郎

出版者

海洋出版

雑誌

月刊地球 (ISSN:03873498)

巻号頁・発行日

vol.35, no.4, pp.180-190, 2013-04

著者

羽鳥 徳太郎

出版者

東北大学

雑誌

津波工学研究報告 (ISSN:09167099)

巻号頁・発行日

vol.29, pp.1-6, 2012-03-30

著者

羽鳥 徳太郎 小山 盛雄

出版者

東京大学地震研究所

雑誌

東京大学地震研究所彙報 (ISSN:00408972)

巻号頁・発行日

vol.49, no.1/3, pp.127-142, 1971-09-30

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For the tsunamis which were generated off the Pacific coast of Japan during the last 76 years (1894-1969), the tsunami travel times observed at 12 tide stations are listed in Table 1. Features of the frequency distribution of travel time for NE Japan are different from those for SW Japan, because of the difference of the geographic characteristics of the tsunami source (Fig. 1). In the former region, a large frequency is found in the range of 30~40min, in contrast to 10~20m in the latter region. Starting from 19 tide stations indicated in Fig. 2, the inverse refraction diagrams of long waves are drawn on bathymetric charts (Figs. 3-12). Wave fronts are shown at 2min intervals. The uncertainty of the diagrams may be within ±2min for most of the regions considered.

著者

羽鳥 徳太郎

出版者

公益社団法人 日本地震学会

雑誌

地震 第2輯 (ISSN:00371114)

巻号頁・発行日

vol.55, no.1, pp.51-57, 2002-07-25 (Released:2010-03-11)

参考文献数

27

著者

羽鳥 徳太郎

出版者

東北大学

雑誌

津波工学研究報告 (ISSN:09167099)

巻号頁・発行日

vol.31, pp.325-328, 2014-03-30

著者

羽鳥 徳太郎

出版者

東京大学地震研究所

雑誌

東京大学地震研究所彙報 (ISSN:00408972)

巻号頁・発行日

vol.58, no.3, pp.723-734, 1984-01-14

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多数の検潮記録を用い,日本海中部地震による津波の波源域,規模などを調査した.波源域は水深2,000mの海域を中心に,津軽・男鹿沖間長さ140km,幅90kmと推定される.津波マグニチュードは,Δ-H曲線からm=2.5と格付けされる.日本海全域の津波伝播図を示し,伝播についての特徴を述べた.また,歴史津波を加え,日本海側でおきた津波の波源域分布を示し,波源域の配列・津波の空白域などを考察した.

著者

高橋 龍太郎 羽鳥 徳太郎

出版者

東京大学地震研究所

雑誌

東京大学地震研究所彙報 (ISSN:00408972)

巻号頁・発行日

vol.40, no.4, pp.873-883, 1963-03-10

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1. There are many theoretical studies on the generation of gravity waves due to an initial surface elevation or to a surface impulse. As to model experiments, however, very few studies have been made on this subject. Recent investigations of after-shocks and the propagation of tsunami waves have revealed that most of the generating area of a tsunami seems to be strongly elliptical in shape. The present experiment has been undertaken to clarify experimentally the characteristics of waves generated by a sudden dislocation of the bottom of elliptic shape. The experiment was carried out in a model basin (25m×40m×0.6m), in Chiba Prefecture, belonging to the Earthquake Research Institute. (Fig. 19). 2. The wave generator is an iron box, 94 cm × 56 cm × 4 cm in size, placed at the bottom level of the basin. It has an elliptic opening on the top covered with a rubber membrane, 2 mm thick, 90 cm × 30 cm (Fig. 20). This elliptic rubber membrane is made to swell out suddenly by compressed air as shown in Figs. 1 and 21. The wave-height gauge is of the parallel-wire type, consisting of 2 stainless steel triangular plates (Fig. 2). The sensitivity of the recorder is such that a deflection of 10mm on the record corresponds to 5.0mm in the water level change. No remarkable effect of capillarity exists in the records. The wave-heights were recorded by a 12-channel portable optical oscillograph. Eleven wave-height gauges were used, the remaining channel of the oscillograph being reserved for recording the motion of the center of the rubber membrane. The oscillograph chart was driven at a speed of either 10 or 30 mm/sec. 3. Records of waves due to the upheaval of the membrane were obtained at every foot from the center of the origin up to 4m and for a water depth of 5.0 cm and 17.3 cm. Details of experimental runs are shown in Table 1 and Fig. 5. A record in Fig. 6 shows the displacement of the center of the rubber membrane when the paper speed is 100 mm/sec. The time of the displacement was fixed at about 1/40 sec for all runs in the experiments. Figs. 7 and 8 show the final forms of the rubber membrane when expanded under certain pressures. Forms may be considered to be nearly a part of a paraboloid. 4. Figs. 22 and 23 are wave-height records for the water depths of 5.0 cm and 17.3 cm respectively. In these records, Nos. 1, 2 and 7 show wave-heights, respectively, just above the center of the origin and at the ends of the short and long axes of the elliptic rubber membrane. No. 12 is a record of the displacement of the centre of the origin. The front of a wave train is propagated roughly with the velocity √gh, except in the immediate neighbourhood of the origin, where a considerably larger velocity is observed. (Fig. 9) Wave trains have a dispersive character as shown in Fig. 11. 5. The initial surface elevation of water above the origin is about half of the displacement of the bottom itself. (Fig. 12). The ratio of the wave-heights at the ends of the long and short axes of the origin area is one-third, but for the positions distant from the origin, this ratio decreases. This result is interesting because the height ratio coincides with the length ratio of the elliptical axes (Fig. 13). The amplitude of an initial crest seems to decrease as r-0.5 and r-0.74 when the depths are 5.0cm and 17.3cm respectively (Fig. 14). Energy of the long-wave can be expressed as follows: E∝rη2L r: distance, η: wave-height, L: length of wave. Then we have EB/EA=(ηB/ηA)2 LB/LA EA, ηA and LA are energy, wave-height and wave length respectively along the long axis. EB, ηB and LB are corresponding quantities along the short axis. At the elliptic margin of the origin we have ηb/ηa = 3, Lb/La = 0.42, therefore Eb/Ea = 3.8, in the case of a water depth of 5 cm. For the distances 1m ≧ r ≧ 4m ηB/ηA = 1.8, LB/LA = 0.40, EB/EA = 1.3 Fig. 16 shows the azimuthal distribution of energy obtained by Run 8. The relation between the wave-length of the waves emitted into a certain direction and the radius of the ellipse in that direction seems to indicate that these two lengths are roughly proportional in the case of shallow water. (Fig. 17).

著者

羽鳥 徳太郎

出版者

東北大学

雑誌

津波工学研究報告 (ISSN:09167099)

巻号頁・発行日

vol.32, pp.13-16, 2015-09-30

著者

羽鳥 徳太郎

出版者

公益社団法人 日本地震学会

雑誌

地震 第2輯 (ISSN:00371114)

巻号頁・発行日

vol.43, no.4, pp.493-498, 1990-12-24 (Released:2010-03-11)

参考文献数

16

被引用文献数

3

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Based on tide-gauge records observed at the Hokkaido and Sakhalin coasts facing the Okhotsk Sea, the characteristics of seven Kurile tsunamis (1918-1978) passing through the straits are investigated. The ratio of wave-heights at the Okhotsk Sea coast to Hanasaki located at the Pacific side was about one-half for tsunamis generating off the Urup Island, and the ratio has a tendency of decrease when the tsunami source moves to western direction toward Hokkaido. It suggests the effective tsunami energy passes into the Iturup Straits than other straits or channels. The travel time at Hanasaki becomes long when the tsunami source moves to the east direction, but that of the Hokkaido-Sakhalin region in the Okhotsk Sea is usually unchanged: For example, travel times of the Kurile tsunamis were mostly about 1.5 hours at Abashiri and 3 hours at Wakkanai. We found through the refraction diagrams that the unchanged travel times were caused by sea-bottom topography in the Okhotsk Sea. The wave rays emitted from the Iturup Straits concentrate in Sakhalin, while those from the Kunashiri Channel concentrate in Hokkaido. For future tsunamis coming-into the Okhotsk Sea, it is indispensable to take into considerations of the effect of tidal currents.

著者

羽鳥 徳太郎

出版者

東北大学

雑誌

津波工学研究報告 (ISSN:09167099)

巻号頁・発行日

vol.29, pp.71-73, 2012-03-30

著者

羽鳥 徳太郎

出版者

東京大学地震研究所

雑誌

東京大学地震研究所彙報 (ISSN:00408972)

巻号頁・発行日

vol.53, no.3, pp.855-861, 1978-12-25

著者

羽鳥 徳太郎

出版者

東京大学地震研究所

雑誌

東京大学地震研究所彙報 (ISSN:00408972)

巻号頁・発行日

vol.54, no.3, pp.543-557, 1980-03-31

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Adding tsunami data reported by the U.S.S.R. sources, tsunami magnitude and the source area of the tsunamis generated in the Hokkaido and Kurile regions during the period from 1893 to 1978 are re-examined. The source dimension and magnitude of the tsunamis generated in the Hokkaido region correspords well with the earthquake magnitude. However, the tsunamis in the Kurile region have varied behaviors. The two Kurile tsunamis of Oct. 20, 1963 and June 10, 1975 were especially abnormal in comparison with other tsunamis accompanied by similar earthquake magnitude. In most cases, the initial motion of the tsunamis was observed with upward direction, but the Kurile tsunamis of Aug. 11, 1969 and June 10, 1975 began with a conspicuous downward motion at the Hokkaido and Kurile tide stations. The source areas of the tsunamis that accompanied large earthquakes (M>8) line up along the continental slope near the Kurile trench and the 1973 Nemuro-oki tsunami was generated in the seismic gap between the 1952 Tokachi-oki and the 1969 Shikotan earthquakes. However, the source area of the 1973 tsunami occupies only the eastern half of the 1894 tsunami source. After the 1973 Nemuro-oki tsunami, the tsunami activity moves to the northeastern direction along the Kurile trench. These source areas fall in the southern part of the source areas of the 1958 Iturup and the 1969 Shikotan tsunamis. In the space-time diagram of the earthquakes having a magnitude of M≧7, remarkable gaps can be seen in the west side of the 1973 tsunami source and off Urup Island. It is possible that a future tsunami of magnitude m~2 may be generated, accompanying the release of seismic energy in the two regions.

著者

羽鳥 徳太郎

出版者

東京大学地震研究所

雑誌

東京大学地震研究所彙報 (ISSN:00408972)

巻号頁・発行日

vol.60, no.1, pp.97-104, 1985-09-05

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小笠原父島における津波記録を収集し,その挙動を考察した.二見港の奥村では,1854年安政東海津波で集落の大部分が流失し,津波の高さは3~4mに達したとみなされる.また,1918年ウルップ(南千島)津波で全振幅2.7mを記録し,19戸が浸水被害を受けた.津波マグニチュード判定図によれば,父島ではフィリピン・ハワイなど南西・南東方向から入射する津波に対して,標準的な振幅で観測されている.しかし,日本近海でおきた津波では,いずれも顕著な波高になり,平均津波マグニチュードより1~1.5階級の偏差(エネルギーで5倍,波高にして2.3倍以上)がある.その要因のひとつとして,小笠原諸島は屈折効果で,津波エルギーが集まることが津波伝播図から認められた.東海地域の津波に対しては,さらに津波の指向性を強く受ける方向にあり,将来の東海地震においては津波に十分な警戒が必要である.

著者

羽鳥 徳太郎

出版者

東京大学地震研究所

雑誌

東京大学地震研究所彙報 (ISSN:00408972)

巻号頁・発行日

vol.46, no.2, pp.345-359, 1968-06

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Making use of data of tsunamis which occurred in the region of South America, frequencies of tsunami generation and of tsunami which propagated to Japan are investigated. Refraction diagrams and the distributions of tsunami height for seven tsunamis which propagated across the Pacific Ocean are shown. Especially, these phenomena along the coast of Japan are shown in detail with the aid of mareograms. The spectral analysis of records obtained in Japan is made for five tsunamis. The generating area of the Chilean tsunami of 1960 is estimated by means of an inverse refraction diagram. This source includes the area of aftershock activity extending about 800 km in an elongated shape.|南米太平洋沿岸で発生した歴史津波の資料によると,波源付近の波高が10m程度の津波によつて日本,ハワイは数回相当な被害を受けている.1900年以後は我が国においても検潮儀によつて7個の津波が観測された.このうち1960年11月20日のペル沖で起きた地震(M=6.75)によつて,微小な津波を観測した例もある.マグニチュードが8.3以上の地震に伴なう津波は,例外なく全太平洋沿岸地域で観観されているが,8.0以下の地震による過去の津波は,日本沿岸で波高50cm以下の微弱なものである.

著者

羽鳥 徳太郎

出版者

東京大学地震研究所

雑誌

東京大学地震研究所彙報 (ISSN:00408972)

巻号頁・発行日

vol.43, no.4, pp.773-782, 1966-03

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Some features of tsunami generated at Middle Aleutian Islands, USA, at 05h 01m(GMT), Feb. 4, 1965 are investigated on the basis of tsunami records taken along the coast of Japan. The predominant wave periods of 14 minutes in addition to seiches on the continental shelf were observed at Miyagi-Enoshima. The present tsunami contained waves of short periods as compared with the tsunamis of 1960(Chile) and 1964(Alaska). At Hachijo Island, conspicuous direct waves emitted from the source were observed. Tsunami waves along the coast of Japan were uniformly decayed with time. The decay coefficient is estimated to be approximately 0.038 per hour.1965年2月4日05時01分21.8秒(GMT),アリューシャン列島中部に大地震が起こり,これに伴なつた津波は全太平洋に伝播し,北海道では地震後3時間30分して第1波を感じ,全日本太平洋岸で波高20~40cm(平常時の潮位上)の津波が観測された.U.S.C.G.S.の観測報告によれば震央は51.3°N,178.6゜E深さ40km,M=73/4(PAS,BEK)である.日本に伝播した津波について,気象庁,水路部,国土地理院から提供された検潮記録および,地震研究所で観測した宮城江ノ島,八丈島,伊豆大島,千葉県金谷の津波計記録を用い津波の概要を紹介し,二,三の考察を行なつた.