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.p143-157, 1986-08

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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

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.3, pp.297-309, 1988-01-29

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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

相田 勇 羽鳥 徳太郎 村井 勇 広井 脩

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.1, pp.p207-242, 1983

被引用文献数

2

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北海道浦河町および浜中町で,津波予報に対する自治体や住民の対応行動の実態を明らかにするため,防災担当者からの実情聴取,住民へのアンケート調査を実施した.昭和57年3月浦河沖地震で,地震災害を受けた浦河町では,地震に対する処理で津波が念頭になかった人が約16%あり,また停電によって情報を得るのに大へん困った人も9.7%という結果が出た.また過去に大きな津波によって,家屋に被災した体験者が過半を占める浜中町では,津波に対する不安感が強く,津波防災意識が高いことがアンケート結果にあらわれている.避難に要する最少限度の時間は,数分乃至10分という結果で,これは津波が100~200m水深の地点から海岸へ到達する時間に見合っている.警報下の船舶の取扱いについては,船のトン数によってかなりはっきりわかれ,小舟は陸へ上げ,大きい船は港外へ避難するという結果が得られている.津波警報は船舶関係老を含めて一般に十分信用して受入れられ,たとえ小津波でも発令することが支持されている.しかし一面では従来の体験をふまえて,各自の判断を加えて行動する自助の意識も強くあらわれている結果となった.In order to investigate the social responses to the tsunami warnings, we conducted letter questionnaires in the towns of Urakawa and Hamanaka in Hokkaido and interviewed officials of the local administrative organs. The results of the questionnaires are as given below. In Urakawa, which was damaged by the 1982 Urakawa-Oki earthquake, about 16 percent of the respondents were so busy settling their damaged houses and furniture that they could not be concerned about the danger of the tsunami. A total of 9.7 percent of the people did not get the news owing to an electrical failure. These results suggest that should a great tsunami immediately follow an earthquake, it might hit the community inhabitants before they can take refuge on the hilltops. In Hamanaka, the majority of the people replied that their houses had suffered some damage from the great tsunamis in the past, while in Urakawa only one percent of the respondents mentioned this. So the people of Hamanaka felt more uneasy about being hit by the tsunami and were more eager about tsunami disaster prevention. But as for the tsunami warnings, the residents of both towns trust them and hope that the Meteorological Agency announces tsunami predictions even though their scale is estimated to be small. They also desire proper measures to make warnings more useful to the local residents. The respondents replied that it takes them five to ten minutes to arrive at the refuge. This is about the same amount of time it takes a tsunami to reach the shore from a point 100 to 200 meters deep after the earthquake occurs. Therefore, it is suggested that if a tsunami off the shore is observed with the tele-meter, we can know in advance when it will hit the shore and quickly work out some countermeasure for it. There are two ways to deal with ships when the tsunami warnings are issued; ships less than 3 tons will be beached, and larger ships will leave the harbor. Our surveys make the fact clear that the inhabitants in general behave properly based on tsunami warnings and their past tsunami experiences.

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.48, no.2, pp.229-233, 1995-08-25 (Released:2010-03-11)

参考文献数

22

被引用文献数

1

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Ten years after the 1983 Nihonkai-Chubu tsunami, the 1993 Hokkaido Nansei-Oki tsunami (magnitude, m=3) hit Okushiri Is., Oshima Peninsula and other regions, Killing 231 people by tsunami and landslide. The distribution pattern of tsunami hfeights is different from that of the 1741 Oshima-Oki tsunami (m=3.5). This paper presents the distribution of cumulative energy, ∑H2, for each 150km segment alomg the Japan Sea coast for the time intervals of the recent 100-year (1894-1994) and of 1600 to 1893 (historical tsunamis). The amount of cumulative energy for the recent and historical tsunamis is largest at the Akita and Oshima-Tsugaru regions, respectively. The cumulative energy at the Akita, Shakotan and other regions for the recent 100-year tsunamis exceeds that of the historical tsunamis. On the contrary, the cumulative energy in the Oshima-Tsugaru and Niigata-Ishikawa regions for the recent tsunamis are small compared with those of the historical tsunamis. Precaution must be paid to these regions for seismic gap may exist there. The total tsunamigenic energy in the Japan Sea comprises 24% of that due to tsunamis in the whole Japan.

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.52, no.1, pp.43-50, 1999-06-30 (Released:2010-03-11)

参考文献数

19

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The Noto Peninsula coast has been suffered from the tsunamis originated along the eastern margin of the Japan Sea. According to the old documents, the 1833 Yamagata-Oki tsunami reached 5.3m at Wajima (tip of Noto Peninsula), and killed 47 persons. Inundation heights of the 1964 Niigata, 1983 Nihonkai-Chubu and 1993 SW. Hokkaido tsunamis were 2-4m at Wajima and its neighboring area. These tsunami heights are more than 2-3.5 times larger than the ones expected from the average tsunami magnitude. Based on the refraction diagrams and the shoaling-refraction factors around the peninsula, amplification factors estimated by the Green's formula are 3.0-4.0 at the north coast, 1.5 at the west coast and 1.0 at the east coast. The distribution patterns of the calculated factors nearly agree with those of the inundation heights for each tsunami. In case of the 1964 Niigata tsunami having the period of about 20min, the seishe of Nanao Bay (east side of peninsula) may be excited, because the maximum wave occurred 2.7 hour late from the initial wave. Tsunamis generated off Yamagata and SW. Niigata are strongly affected by the shoaling-refraction.

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.50, no.4, pp.385-395, 1976-03-31

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.2, pp.329-338, 1986-12-10

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ソ連沿海州・北朝鮮および韓国沿岸からの津波伝播図を作図し,1983年日本海中部地震津波において,波源から射出された津波が大陸から反射して日本沿岸に到達する時間を調べた.そして各地で観測された検潮記録の波形との対応を検証した.その結果,発震時から2~5時間の間に,各地で顕著な振幅が発現した時刻が,大陸からの反射波の到達時間と±10分以内で合致しており,積丹半島・能登半島周辺および山陰地方に,波向線が集まることが認められた.将来,日本海に発生する津波の予報にあたっては,大陸からの反射波の動向も注目する必要がある.

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.28, no.4, pp.461-471, 1975-12-10 (Released:2010-03-11)

参考文献数

14

被引用文献数

6

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Adding mareographic data at the Kuril Islands, the source areas of the 1973 Nemuro-oki tsunami and the 2nd tsunami accompanying the largest aftershock on June 24, 1973 are reanalyzed. The result is the same as shown in the preliminary report: The source length of the 1973 Nemuro-oki tsunami is 130km long parallel to Nemuro Peninsula and the area is 7.2×103km2. The source length of the 2nd tsunami is 100km which is longer than the aftershock area reported by NOAA, and the western half of the source area seems to overlap with the source area of the first tsunami.The 3rd tsunami of Sept. 27, 1974 was observed with small amplitude at Hanasaki. The estimated source area of this tsunami is within the source area of the 1973 tsunami. The 4th tsunami of June 10, 1975 was generated by an earthquake with the magnitude of about 7 (JMA), but the tsunami magnitude was relatively large. According to the author's method based on the attenuation of tsunami height with distance, the tsunami magnitude (Imamura-Iida scale) is m=1.5. This magnitude is the same grade to that of the 1973 Nemuro-oki tsunami. The estimated source area falls inside the source area of the 1969 Shikotan tsunami. The source length is about 100km long and its area is 6.3×103km2. The sea-bottom of this area may be uplifted, judging from the initial motion of the tsunami observed at Hokkaido and Sanriku.The source areas of the tsunamis generated after the 1973 Nemuro-oki tsunami moved to the north-eastern direction along the continental slope. Within the source area of the 1969 Shikotan tsunami, many tsunami sources are located. On the contrary, there is a remarkable gap of the tsunami source area between the 1952 Tokachi-oki and the 1973 Nemuro-oki tsunamis. The source area of the 1973 tsunami occupies only the eastern half of the 1894 tsunami source. The area to the south-west of the 1973 tsunami may be considered a region of relatively high tsunami risk.

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.51, no.1, pp.13-28, 1976-08-31

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.3, pp.439-459, 1986-02-07

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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 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

東京大学地震研究所彙報 (ISSN:00408972)

巻号頁・発行日

vol.58, no.1, pp.187-206, 1983-07-28

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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

東京大学地震研究所彙報 (ISSN:00408972)

巻号頁・発行日

vol.59, no.4, pp.501-518, 1985-03-30

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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

東京大学地震研究所彙報 (ISSN:00408972)

巻号頁・発行日

vol.53, no.4, pp.1191-1225, 1979-03-31

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.56, no.3, pp.547-570, 1982-01-08

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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

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.26, no.2, pp.204-205, 1973-10-30 (Released:2010-03-11)

参考文献数

8

被引用文献数

1

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

地震研究所研究速報

巻号頁・発行日

vol.8, pp.58-62, 1964-09

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昭和39年6月16日新潟地震調査概報

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.51, no.2, pp.203-210, 1998-10-15 (Released:2010-03-11)

参考文献数

21

被引用文献数

1

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The generating frequency of the North-West American tsunamis is relatively lower than that of the South American region, but there are historical records of a large tsunami accompaning with the January 1700 earthquake (M 9) in the Cascadia subduction zone (SATAKE et al., 1996). In the present paper, tsunami magnitudes on the Imamura-Iida scale, m, are investigated by using the diagram of wave-height attenuation with distance. The regional characteristics of tsunami magnitudes are discussed in relation to earthquake magnitudes, Ms, during the period from 1899 to 1997. The tsunami magnitudes in the South-East Alaska to Canada region are nearly normal compared to earthquakes with similar size in the other Pacific regions, and the 1899 Yakutat tsunami being m=3 is the largest. The magnitude values in the California region are mostly m=0 or less (amplitude: 50-100cm), but those of a few tsunamis vary by the faulting mechanism. For example, the magnitude value of the 1906 San Francisco tsunami accompaning with a strike-slip earthquake (Ms=8.3) is m=-4. On the contrary, that of the 1927 Lompoc tsunami caused by a high-angle thrust earthquake (Ms=7.0) is m=1, and this tsunami was observed in Hawaii and Japan. According to the epicenter distribution of the earthquakes (Ms≥6.5) since 1812, a seismic gap exists at the segment of 700km off the Washington to Oregon states. It should be considered a region of relatively high tsunami risk.

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.50, no.4, pp.385-395, 1976-03-31

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.58, no.3, pp.683-689, 1984-01-14

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熱海・初島において,1923年関東地震津波について,地震体験者の住民から聞きとり調査を行った.熱海では当時の海岸から約200m,地盤高がT.P.上7m以下の市街地に浸水したことが分った.熱海中心部の海岸では津波の高さは7.0~8.0mと推定される.一方,初島では地盤が隆起して集落内に津波は侵入せず,津波の高さは1.8m程度であった.

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.37, no.1, pp.23-29, 1984-03-25 (Released:2010-03-11)

参考文献数

10

被引用文献数

1 1

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By applying the Greens's law, the sea-level disturbance at the source area of the Nihonkai-Chubu tsunami (May 26, 1983) is calculated from the coastal inundation heights. By means of the same method, the volumes of the displaced water at the source area, V0, for 18 tsunamis are calculated, where the tsunami source area and the shoaling and refraction factors of the coastal heights are analyzed on the inverse and refraction diagrams, respectively. It is found that V0 is closely related to seismic moment, M0.1) For the 1983 Nihonkai-Chubu tsunami, the height of the sea-level disturbance averaged over the tsunami source area is estimated to be 123cm, and the peak of 202cm seems to have disturbed in the southern part of the source area. The volume of the displaced water V0 is 12.3×1015cm3.2) The relation between V0 and tsunami magnitude (Imamura-Iida scale, m) is expressed aslogV0=0.6m+14.7, where the unit of V0 is ×1015cm3. Combining V0 and the seismic moment M0 (dyne-cm), which is empirically expressed aslogV0=0.78logM0-6.23.However, the V0 values for the 1896 Sanriku and 1946 Aleutian tsunamis such as “tsunami earthquake” and the Japan Sea tsunamis (the 1940 Shakotan, 1964 Niigata and the present tsunamis) generated by the high angle fault are three times larger then those of the obtained from the above equation.