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.44, no.4, pp.297-303, 1991-12-24 (Released:2010-03-11)
参考文献数
13

Based on an epicentral distance dependence of tsunami amplitude observed at tide stations, the tsunami magnitudes were obtained to be m=-2 and m=-1 for the Oshima-Kinkai tsunami of Feb. 20, 1990 and the Tokaido-Oki tsunami of Sept. 24, 1990, respectively. The locality on magnitudes of the tsunamis generated along the Izu-Mariana Island-Arc since 1900 are discussed in relation to earthauake magnitude. According to the statistical relation, the magnitude values (Imamura-Iida scale) of the tsunamis generated near the trench triple junction off Boso Peninsula are one to two grades larger than the average tsunami magnitude. Such tsunamis were mostly caused by low-frequency earthquake with the high-angle dip-slip fault. While, the magnitudes of the tsunamis generated off the west side of Oshima Is. are one grade less than the average value, with caused by earthquakes of the strike-slip type. The magnitudes of a few tsunamis generated on the ridge were larger than the average value. Especially, the 1984 Torishima-Kinkai tsunami had an abnormal magnitude. The regional difference of seismic mechanisms were found by the deviation of tsunami magnitudes.
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.62, no.2, pp.133-147, 1987-10-23

日本海側に発生した元禄7年(1694)能代地震・宝永元年(1704)岩館地震・寛政4年(1793)鯵ケ沢地震および文化7年(1810)男鹿地震について,新史料を加えた震度分布図を示し,地震の規模を検討した.一方,史料をもとに各地の津波の高さを現地調査し,津波の規模を考察した.1939年男鹿地震(M=7.0)の震度分布と比べると,鯵ケ沢地震の規模はM=7.2,能代地震・岩館地震・男鹿地震はいずれもM=7.0と推定される.これらのマグニチュード値は,従来のものより0.1~0.2大きい.鯵ケ沢地震では鯵ケ沢~深浦間で3~5mの波高が確められ,津波マグニチュードはm=1と推定される.岩館地震の潮位記録は,深浦~滝ノ間間で0.6~1.4mの津波が伴ったことを示唆しており,津波マグニチュードはm=Oとみなせる.また,能代地震・男鹿地震では20~30cmの津波があったと考えられる.震度・津波および地殻変動のデータを考え合せると,震源域は西津軽~男鹿沿岸にそって並び,震源の大きさは30~50kmと推定される.
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.55, no.2, pp.505-535, 1980-11-15

There are many old monuments of the Nankaido tsunamis of Hoei (Oct. 28, 1707) and the 2nd Ansei (Dec. 24, 1854) along the Osaka and Wakayama coasts, Western Japan. Most of these monuments were built just after the earthquakes to pray for the repose of the tsunami victims or to sound a warning to inhabitants. In this paper, the tsunami monuments are illustrated. Based on descriptions on the monuments, adding new data collected from the present field investigation, inundation heights of the 1707 Hoei and 1854 Ansei tsunamis along the Wakayama coast are surveyed by hand-level. Behaviors (inundation height and area) of the two historical tsunamis are compared with those of the 1946 Nankaido tsunami (Dec. 21, 1946). Inundation heights of the 1854 Ansei tsunami along the Wakayama coast, the west side of the Kii Peninsula, are 4.8 meters on the average and are 1.2 times as large as those of the 1946 Nankaido tsunami. The estimated heights of the 1707 Hoei tsunami are 5 meters with the localized run-up maximum of 6 to 7 meters. Along the Wakayama coast, the patterns of height distribution of the two historical tsunamis are similar to that of the 1946 Nankaido tsunami. However, the inundation heights of the 1707 Hoei and 1854 Ansei tsunamis along the coast in Osaka Bay are three times as large as those of the 1946 tsunami. Osaka suffered severe damage and many persons were drowned by the two tsunamis of 1707 and 1854. Estimated heights were about 3 meters. It suggests that the wave periods of the two historical tsunamis were longer than those of the 1946 tsunami. Although the source dimensions of the two historical tsunamis are similar to the 1946 tsunami (The source areas of three tsunamis extend 250 km along the Nankai trough), the rise times of crustal deformation for the two historical earthquakes differ significantly from the 1946 earthquake.
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.61, no.1, pp.143-157, 1986-08-04

秋田県南部の象潟・金浦海岸に顕著な地殻変動と地震・津波被害をもたらした文化元年(1804年)象潟地震について,新史料を加えて震度分布を調べ,地震の規模を検討した.一方,津波史料をもとに各地の津波の高さを現地調査し,津波の規模および発生機構を考察した.震度6の範囲が本荘~酒田間60kmに及んだことは,今村の報告(1921)と変わりはないが,震度4の地域は青森・宮城県および新潟県下にまたがつた.その広がりから地震のマグニチュードはM=7.3と推定される.海岸の地盤高をふまえて津波の被害状況をみると,津波の高さは象潟付近で平均海面上4~5m,酒田では3~4mと推定される.そのほか周辺の波高分布から判断すれば,津波マグニチュード(今村・飯田スケール)はm=1.5と格付けできる.震度・地殻変動の分布を考え合せると,波源域の長径は本荘~酒田沿岸南北方向に,60kmと推定される.津波の規模は地震の規模に対して標準以上に大きく,この津波は高角の逆断層で起こされたものと考えられる.
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.27, no.4, pp.321-337, 1974-12-30 (Released:2010-03-11)
参考文献数
51
被引用文献数
6

Source areas of the tsunamis generated in northeast Japan since 1896 are compiled on a bathymetric chart (Newly estimated: 14; Reanalyses: 14). Sources of large tsunamis lie on the steep continental slope off the Sanriku coast. Most of small tsunami sources are located in the sea shallower than the depth of 2000m. Source dimensions are closely related with earthquake magnitude; the Utsu formula for the relation between the earthquake magnitude and aftershock area can be applied well for the tsunami source area. Generally speaking, the magnitudes of tsunami correspond to earthquake magnitude. However, a few tsunamis generated in the vicinities of the west Aomori and Miyagi regions are especially small in comparison with those at other regions.Judging from the initial motion on tsunami records, most of tsunamis off the Sanriku coast seem to be generated by the reverse fault type earthquake. The sense, up or down, of the initial motion of the 1896 Sanriku tsunami is opposite to that of the 1933 tsunami which is caused by a normal fault earthquake. This suggests that the 1896 tsunami was generated by the reverse fault earthquake. Source dimension of the 1933 tsunami is newly revised and found to be about 300km. This area is smaller than the former estimations, because arrival times at the tide stations of Hokkaido were read too early by misunderstanding a noise as the first motion.
著者
羽鳥 徳太郎
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.3, pp.439-459, 1986-02-07

寛文・明和日向灘津波および宝永・安政南海道津波について,史料をもとに大分・宮崎県沿岸各地を現地調査し,津波の高さ,浸水域の広がりを考察した.寛文津波は宮崎平野に広く浸水し,津波の高さは4~5mと推定される.明和津波は大分県沿岸で2~2.5mの波高があり,津波よりむしろ地震災害が上回った.津波マグニチュードは,それぞれm=2と1に格付けできる.両津波の震度・波高分布および地殻変動の記録を近年の日向灘津波と比べると,波源域はいずれも沿岸付近にあったとみなされる.一方,宝永南海道津波は大分・宮崎県沿岸各地の集落に溢れ,津波の高さは3~4.5mに達している.また,熊本・長崎県沿岸にも浸水記録があり,30分程度の長周期波が卓越したことを暗示する.安政南海道津波は宝永津波よりやや小さく,大分・宮崎県沿岸の波高は2~3mと推定される.両津波の規模および震度が1946年南海道津波を上回り,予想以上に九州各地に強い影響を与えていることから,波源域が1946年津波のものより四国の南西沖に伸びていたことを考えさせる.
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.56, no.3, pp.547-570, 1982-01-08

The west coast of Kii Peninsula and Shikoku, western Japan, suffered severe damage from the three Nankaido tsunamis of 1707, 1854 and 1946. There are many old monuments of the 1854 Ansei tsunami along the Kochi coast. Old documents on the Hoei (Oct. 28, 1707) and Ansei (Dec. 24, 1854) tsunamis along the southwest coast of Kochi Prefecture were collected during the present field investigation and illustrated in this paper. Based on the documents, the inundation heights of the 1707 Hoei and 1854 Ansei tsunamis were surveyed by handlevel and compared with those of the 1946 Nankaido tsunami (Dec. 21, 1946). The inundation heights (above M. S. L.) of the 1854 Ansei tsunami along the southwest coast of Kochi averaged 5.5 meters. Those of the 1707 Hoei tsunami averaged 7.7 meters with maximums of 10 meters at places. Although the inundation heights of the 1946 tsunami along the entire Pacific side of Shikoku were nearly uniform, the patterns of height distribution along the west coast of Shikoku for the 1707 and 1854 tsunamis differ significantly from those of the 1946 tsunami. The inundation heights of the 1854 Ansei and 1707 Hoei tsunamis on the western Shikoku coast were 1.5 and 2.1 times respectively, higher than those of the 1946 tsunami. This suggests that the rise times and/or the amount of the slip displacements on the west part of the fault might be different.
著者
羽鳥 徳太郎 相田 勇 坂下 至功 日比谷 紀之
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.58, no.1, pp.187-206, 1983-07-28

Yuasa and Hiro located on the west side of Kii Peninsula, western Japan, have been hit by many large tsunamis which were generated about every 100 to 150 years. Sources of all these tsunamis were offshore between Wakayama and Shikoku along the Nankai Trough. Traces of the inundated level on many houses in the two towns caused by the 1946 Nankaido tsunami (Dec. 21, 1946) were surveyed, using the automatic level from Oct. 18 to 23, 1982. The behavior of the 1946 tsunami run-up on land was investigated and compared with the two historical tsunamis of Hoei (Oct. 28, 1707) and Ansei (Dec. 24, 1854). The results of the present survey are as follows: (1) At Yuasa, the inundation heights of the 1946 tsunami were 3.0-3.5 meters above M.S.L. Ground about 3.0 meters above M.S.L. was inundated, so that 450 houses were inundated but hardly any were washed away. At Hiro, the sea wall strongly protected the main part of town from the 1946 tsunami (This bank was constructed just after the 1854 Ansei tsunami from Mr. Goryo Hamaguchi's personal funds). However, the tsunami energy concentrated at the head of bay along the Egami River. The inundation heights locally reached 5 meters (above M.S.L.) or more and 22 persons were killed. (2) According to old documents, the inundation area of the 1707 Hoei tsunami elongated along the Yamada, Hiro and Egami Rivers. Forty-one lives were lost at Yuasa and 192 at Hiro. Inundation heights above M.S.L. were estimated 4-5 meters at Yuasa and 5-6 meters at Hiro. (3) By the 1854 Ansei tsunami, 28 lives were lost at Yuasa and 36 at Him. The patterns of damage at Yuasa and Hiro are similar to those of the 1707 Hoei tsunami. There remain even now traces of the inundation level on a few old houses in both towns. Inundation heights above M.S.L. were 4.0-4.7 meters at Yuasa and 5.0 meters in the center of Hiro town. Ground about 4.0 meters above M.S.L. was inundated, 0.7 to 1 meter higher than that during the 1946 Nankaido tsunami.
著者
羽鳥 徳太郎
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.1, pp.87-95, 1985-09-05

1984月6年13日,鳥島近海地震(M=5.9)によって,伊豆諸島をはじめ,房総から四国に至る沿岸各地の検潮所で全振幅10~57cm,周期5~9分の津波が観測された.また,八丈島の八重根漁港では,最大波の全振幅130~150cmの津波が目撃された.検潮記録によれば,津波マグニチュードはm=0と格付けされ,地震規模に対して津波が異常に大きい“津波地震”であった.波源域は須美寿島(八丈島南方190km)西側の水深1,000mの伊豆・小笠原海嶺にあり,波源域の長さは25kmと推定される.津波初動の押し引き分布から判断して,波源の西側の海底が隆起し,東側が沈降したとみなされる.
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.62, no.3, pp.297-309, 1988-01-29

寛政5年1月7日(1793年2月17日)宮城沖に発生した地震の震度分布およびそれに伴う津波の高さを,新史料をもとに調べ,近年の宮城沖地震との比較から地震と津波の規模および波源域を考察した.各地の史料を調べた結果,震度5の範囲は岩手県中部から福島県北部に至る内陸部に分布し,震度4の範囲は東北地方から関東地方に広くまたがることが示された.1933年三陸地震・1978年宮城県沖地震などの震度分布との比較から,寛政地震のマグニチュードはM=7.8と推定された.一方,この地震に伴う津波の高さは,岩手県中部~牡鹿半島沿岸で3~5m,福島県沿岸では2~3mと推定された.筆者の方法(羽鳥,1986)によれば,津波マグュチュード(今村・飯田スケール)はm=2.5と見つもられ(1968年十勝沖津波と同じ規模),従来推定されていた値よりもやや大きい.震度および津波の高さの分布から,波源域は1897年8月の宮城沖津波の波源域を含むかたちで海溝付近にあり,長さ200km,幅80km程度の大きさであったと考えられる.
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.59, no.4, pp.501-518, 1985-03-30

関東・伊豆東部沿岸を対象に,宝永・安政東海津波における各地の史料・伝承記録を集め,両津波の挙動を調査した.安政津波は,伊豆東部沿岸の集落内に遡上し,津波の高さは3~6mに推定され,半島の付け根付近が高い.また,東京湾では東京・浦安・横浜の河口付近に溢れている.1923年関東地震津波と比べると,相模湾沿岸では津波の高さは下回つたが,外房・九十九里浜では集落に溢れ2倍ほど上回った.宝永津波の高さの分布は,安政津波とほぽ似たパターンを示している,両津波の高さが予想外に大きい要因の一つとして,南海・駿河トラフで発生した津波がエッヂ波のように伊豆東海岸に伝わり,加えて波の屈折効果が作用したものと考える.
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.2, pp.505-535, 1980-11-15

There are many old monuments of the Nankaido tsunamis of Hoei (Oct. 28, 1707) and the 2nd Ansei (Dec. 24, 1854) along the Osaka and Wakayama coasts, Western Japan. Most of these monuments were built just after the earthquakes to pray for the repose of the tsunami victims or to sound a warning to inhabitants. In this paper, the tsunami monuments are illustrated. Based on descriptions on the monuments, adding new data collected from the present field investigation, inundation heights of the 1707 Hoei and 1854 Ansei tsunamis along the Wakayama coast are surveyed by hand-level. Behaviors (inundation height and area) of the two historical tsunamis are compared with those of the 1946 Nankaido tsunami (Dec. 21, 1946). Inundation heights of the 1854 Ansei tsunami along the Wakayama coast, the west side of the Kii Peninsula, are 4.8 meters on the average and are 1.2 times as large as those of the 1946 Nankaido tsunami. The estimated heights of the 1707 Hoei tsunami are 5 meters with the localized run-up maximum of 6 to 7 meters. Along the Wakayama coast, the patterns of height distribution of the two historical tsunamis are similar to that of the 1946 Nankaido tsunami. However, the inundation heights of the 1707 Hoei and 1854 Ansei tsunamis along the coast in Osaka Bay are three times as large as those of the 1946 tsunami. Osaka suffered severe damage and many persons were drowned by the two tsunamis of 1707 and 1854. Estimated heights were about 3 meters. It suggests that the wave periods of the two historical tsunamis were longer than those of the 1946 tsunami. Although the source dimensions of the two historical tsunamis are similar to the 1946 tsunami (The source areas of three tsunamis extend 250 km along the Nankai trough), the rise times of crustal deformation for the two historical earthquakes differ significantly from the 1946 earthquake.
著者
羽鳥 徳太郎
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.62, no.2, pp.133-147, 1987-10-23

日本海側に発生した元禄7年(1694)能代地震・宝永元年(1704)岩館地震・寛政4年(1793)鯵ケ沢地震および文化7年(1810)男鹿地震について,新史料を加えた震度分布図を示し,地震の規模を検討した.一方,史料をもとに各地の津波の高さを現地調査し,津波の規模を考察した.1939年男鹿地震(M=7.0)の震度分布と比べると,鯵ケ沢地震の規模はM=7.2,能代地震・岩館地震・男鹿地震はいずれもM=7.0と推定される.これらのマグニチュード値は,従来のものより0.1~0.2大きい.鯵ケ沢地震では鯵ケ沢~深浦間で3~5mの波高が確められ,津波マグニチュードはm=1と推定される.岩館地震の潮位記録は,深浦~滝ノ間間で0.6~1.4mの津波が伴ったことを示唆しており,津波マグニチュードはm=Oとみなせる.また,能代地震・男鹿地震では20~30cmの津波があったと考えられる.震度・津波および地殻変動のデータを考え合せると,震源域は西津軽~男鹿沿岸にそって並び,震源の大きさは30~50kmと推定される.
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.3, pp.429-438, 1986-02-07

津波史料をもとに別府湾沿岸を現地調査し,地盤高をふまえて各地の津波の高さ(平均海面上)や浸水域の広がりを検討した.大分市内では,流失した寺院の分布から津波の高さは4~5.5mに推定され,地盤高ぶおよそ4m以内の範囲が浸水域とみなされる.別府湾口の奈多と佐賀関ではそれぞれ7~8mと6~7mの波高に達し,湾外の上浦で4m,臼杵では3~4mと推定される.津波マグニチュードは今村・飯田スケールでm=2と格付けされる.津波・震度分布および周辺のテクトニクスから判断すれば,波源域は別府湾を包み東西方向に50km程度の長さがあったと推定される.また,瓜生島・神場洲の地盤沈降の記録は別府湾が陥没したことを暗示し,高角正断層の地震により津波が発生したと考える.