著者

広田 知保

出版者

北海道大学理学部地球物理学教室

雑誌

北海道大学地球物理学研究報告 (ISSN:04393503)

巻号頁・発行日

vol.21, pp.33-43, 1969-02-15

著者

Hatori Tokutaro

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.48, no.3, pp.399-412, 1970-08-31

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A tsunami was generated off Shikotan Island, in eastern Hokkaido, at 21 h 28m (GMT) on August 11, 1969. According to JMA, the epicenter of the main shock was at 42°42'N, 147°37'E, with a depth of 30km and the earthquake magnitude 7.8. Tsunami height observed at the coast of eastern Hakkaido was the largest among tsunamis generated recently in the vicinity of the South Kuril Islands. At Hanasaki, the maximum height of 1.5 m was recorded. Waveheights in northeastern and southwestern Japan are in the ranges of 40~60 cm and 20~30 cm, respectively. The initial motion of the tsunami was in an upward direction at most stations, but at Hanasaki, the initial disturbance began with a conspicuous downward motion, suggesting the subsidence of the sea bottom in a part of the tsunami source. The source area estimated by means of an inverse refraction diagram lies on the continental slope, extending about 170km parallel to the Kuril Arc. Judging from the attenuation of the initial wave height with distance, the total wave energy seems to be equal to that of the 1958 Iturup tsunami. The predominant period of tsunami incident to the shelf is inferred to be about 30min by comparing the spectrum of tsunami with that of the records at the ordinary time near Miyagi-Enoshima.|1969年8月12日6時28分(JST),北海道色丹島沖の地震に伴ない津波が発生した.気象庁の地震月報によると,震央は42°42'N,147°37'E,深さ30km,地震のマグニチュードはM=7.8である.この津波は,本震が起った約30分以後から各地の検潮所で観測された.津波の第1波は,本州とオホーツク海に面した北海道沿岸では押し波で始まつた.しかし,波源に近い花咲では明瞭な引き波が記録され,波源域の1部分が沈降したことを暗示している.各地の津波の到達時間をもとにして作図した逆伝播図によると,津波の波源域は色丹島沖合の水深2000~4000mの陸棚斜面上にあつて,等深線に沿つて伸び,その大きさは約170kmと推定される.この程度の規模を持つ浅い地震に対して,この推定値は統計的に標準の大きさである.なお,推定源域は余震域とほぼ合致した位置にある.

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.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

大邑 潤三

出版者

立命館大学歴史都市防災研究所

雑誌

歴史都市防災論文集 = 歴史都市防災論文集 (ISSN:18821766)

巻号頁・発行日

vol.8, pp.63-70, 2014-07

著者

Barrows Jason S.

出版者

北海道大学教育学部教育方法学研究室

雑誌

教授学の探究 (ISSN:02883511)

巻号頁・発行日

vol.16, pp.123-134, 1999-03-05

著者

酒井 昭

出版者

北海道大学低温科学研究所

雑誌

低温科學. 生物篇 (ISSN:04393546)

巻号頁・発行日

vol.22, pp.29-50, 1964-10-20

著者

都司 嘉宣 佐竹 健治 石辺 岳男 楠本 聡 原田 智也 西山 昭仁 金 幸隆 上野 俊洋 室谷 智子 大木 聖子 杉本 めぐみ 泊 次郎 Heidarzadeh Mohammad 綿田 辰吾 今井 健太郎 Choi Byung Ho Yoon Sung Bum Bae Jae Seok Kim Kyeong Ok Kim Hyun Woo

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.86, no.3-4, pp.29-279, 2012-03-16

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We report the results of field surveys conducted by the Earthquake Research Institute, to measure tsunami heights from the 2011 off the Pacific coast of Tohoku, Japan Earthquake (M 9.0), on March 11. Measurements were taken at 296 points on the Sanriku coasts of Aomori, Iwate, and Miyagi Prefectures, and the Pacific coasts of Ibaraki and Chiba Prefectures. The data are included in the results of the 2011 Tohoku Earthquake Tsunami Joint Survey Group. We did not cover the Sendai plain in the southern Miyagi Prefecture because other parties extensively measure there, nor Fukushima Prefecture because of the accident of the Fukushima Dai-ichi nuclear power plant. The twelve surveys first sought traces indicating tsunami runup or inundation heights. Reliability was classified into A (most reliable based on clear physical evidence and eyewitness accounts), B (mostly based on natural traces), and C (least reliable based on equivocal evidence). Most physical evidence obtained after June was not significant; therefore, reliance was mostly placed on eyewitness accounts. Locations and relative heights above sea level were measured using handheld GPS receivers, auto-level, or total station. The measured heights were corrected for differences in tide level between measurement time and tsunami arrival time. The results are shown on table and four regional maps; however, the details of each measurement, including locations shown on 1:25,000 maps and photographs of evidence are shown in the Appendix. Along the northern Sanriku coast (Aomori and Iwate), most of the 141 heights range between 10m and 30m. Runup heights exceeding 30m were measured at one location in Noda Village and nine locations in Miyako City. On the southern Sanriku coast in Miyagi, most of the 76 measurements range between 4 and 20 m. On the Ibaraki coast, 36 measurements range from 2.8 to 8.1 m, and the heights generally decease toward the south. On the Chiba coast, 43 measurements range from 0.7 to 7.9 m, with the maximum height near Iioka, Asahi City.

著者

Hashimoto Naoki

出版者

Kyoto University

巻号頁・発行日

1971-07-23

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新制・論文博士

著者

關谷 清景

出版者

震災豫防調査會

雑誌

震災豫防調査會報告

巻号頁・発行日

vol.26, pp.4-8, 1899-02-08

著者

野口 和子 中村 操 津村 建四朗 大迫 正弘

出版者

東京大学地震研究所

雑誌

技術研究報告 (ISSN:13426486)

巻号頁・発行日

vol.13, pp.147-162, 2007

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<その他>

著者

Kawasumi Hirosi

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.28, no.3-4, pp.355-367, 1951-03-25

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昭和24年12月26日朝8h 16m及8h 25mに栃木縣上都賀郡今市町附近を中心とする小區城破壊的地震が起り,死者8,行方不明2,全潰住家299戸半潰住家618戸の被害を生じた.此の地震の震央附近の震度は極めて強かつたようであるが,振動週期極めて小なりし爲か石藏家屋の外は全潰(現建築費50%以上の損害)とは云へ倒潰と云ふやうなものは少かつた.從つて火事の發生を見なかったのは幸であつた.然し山崩,地辷りは極めて著しく,山地田畑の荒廢著しく,人命の損失の大部分もこれによるものであつた.余震の頻發した事,及び初動の圓錐型分布,及び所謂地震斷層と思はれる如きものの見へなかつた事も本地震の特徴と云ふべく,今市町全體に互る地震後井戸壁の變形から約6mの厚さの地層が東方に約6cm移動した事が判明したが,之は測地學上重要問題を指唆するものである.尚水準測量の結果は今市町近傍數粁の間だけ約30~40cmの隆起があつた由である.震後の火山活動との關係も興味ある問題であらう.

著者

宮村 攝三 秋間 哲夫

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.28, no.3-4, pp.421-433, 1951-03-25

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Nach dem letzten starken Lokalbeben vom 27. Dezember 1919 bei der Stadt Imaichi(139°42′E, 36°42′N) wurde wie gewohnlich eine Expedition unseres Institutes fur die Nachbebenbeobachtungen nach dem epizentralen Gebiet gesandt, und eine Zweigstation derseben am Dorfe Hunyu(139°47′E, 36°45′N)(s. Fig.2) wurde den Verfassern aufgetragen. Die dabei verwendeten neuen Verbesserungen in Ausrustung und Methode fur Nachbebenbeobachtung im Felde waren wie folgt: 1) Gebrauch von Dreikomponentenseismographen mit gleichen Konstanten, T0=0.08, V≒200, fur jede Komponente. 2) Konstantenbestimmung an der Messtelle durch dynamische Prufung.(s. Fig.1) 3) Verwendung von einem Prazisions-registrierapparat, die eine grosse Trommel(d=195.5mm, l=740mm) fur drei-komponenten Registrierung hat und durch einen von Bifilarpendel regulierten Gleichstrommotor betrieben wird. 4) Vergrosserung von Papiergeschwindigkeit der Registrierung.(d. h. ca. 2.5mm/sec) 5) Sekundenzeitmarkierung durch einen mit Radiosignal verglichenen Chronometer. u.s.w. Folglich wurden die exakten Einsatzzeiten von P bis auf 1/10 Sekunde beinah zum ersten Mal in Feldbeobachtung der Nachbeben bestimmt. In Tabelle I ist ein Teil der Daten von 27 Beben zusammengestellt, deren Herdlagen durch P-S.Zeiten an 3 oder 4 Stationen bestimmt werden konnten. Einige Reproduktionen der Seismogrammen sind in Fig.3~8 gezeigt. Zwar man die naheren seismometrischen Studien nicht aus der Beobachtung von dieser einzigen Station(da andere Zweigstationen keine Zeitmarkierung und genugend schnelle Papiergeschwindigkeit batten) durchfuhren kann, konnen wir doch fur jetzt nur sagen, dass 1) P, S, und andere Einsatze aus einer einzigen Komponente nicht sicher bestimmt werden konnen, 2) bei gewissen Beben viele Phasen zwischen P und S bald in eine bald in andere Komponente klar festgestellt werden konnen, wahrend bei anderen Beben keine solchen Einsatzen klar gefunnden werden, 3) in gewissen Beben kurz vor dem scharfen P in Vertikalkomponente eine leichte Bewegung getroffen wird.(s. Fig.9) Leider finden diese Tatsachen 1)~3) fur jetzt noch keine genugende Erklarung. Ubrigens zeigten hier die Seismogrammen merkwurdige Bodenunruhe bei Tage besonders in O-W-Komponente. Zwar die Ursache dieser Bodenschwingung die umliegende Sagemuhle(1-9 in Fig.13) ist, gibt es keine direkte Relation zwischen der Periode der Bodenschwingungen und der der Motoren. Die Uberwiegung in O-W-Komponente wurde auch von in N-S betriebenen Muhlen klar erzeugt, und daher mussen wir es zu einer Bodenanisotropie zuschreiben.(s. Fig.14) Freier Fall einer 12 Pfund Kugel von 1m Hohe wurde auf den Boden in der Nahe 2~6m von Seismographen versucht.(s. Fig.15) Amplitudenverkleinerung mit der Herddistanz ist in Fig.16 gezeigt und dort kann man keine obengenannte Anisotropie des Bodens finden. Wenn man die Amplitude y mit Herddistanz x in der Gleichung y=Ax-n e-kx darstellen kann, kann man die Konstanten n und k aus diesem Experiment rechnen.(s. Tabelle II) Z. B. bei Vertikalbewegung sind n zwischen 1 und 1/2, und dies zeigt, dass die Wellenausbreitung wenigstens in diesem Fall sozusagen zwischen die der Oberfiachenwellen und die der Raumwellen ist.

著者

Koto Bundjiro

出版者

College of Science, Imperial University

雑誌

The journal of the College of Science, Imperial University, Japan = 帝國大學紀要. 理科

巻号頁・発行日

vol.2, pp.77-141, 1889

著者

大澤 正之 阿部 豊

出版者

北海道大學農學部演習林

雑誌

北海道大學農學部 演習林研究報告 (ISSN:03676129)

巻号頁・発行日

vol.14, no.2, pp.186-207, 1949-12

著者

福山 伍郎 川瀨 淸

出版者

北海道大學農學部演習林

雑誌

北海道大學農學部 演習林研究報告 (ISSN:03676129)

巻号頁・発行日

vol.17, no.1, pp.151-178, 1954-03

著者

南 尚貴 戸田 正憲 別府 桂

出版者

北海道大学農学部演習林

雑誌

北海道大學農學部 演習林研究報告 (ISSN:03676129)

巻号頁・発行日

vol.36, no.2, pp.479-507, 1979-07

著者

YOKOTA Shun-ichi

出版者

東京大学大学院農学生命科学研究科附属演習林

雑誌

東京大学農学部演習林報告 (ISSN:03716007)

巻号頁・発行日

vol.52, pp.165-171, 1956

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It is natural that butt rot fungi should invade healthy trees through scars on the trunk. Besides, one of the modes of infection and propagation of butt rot was discovered by dissecting in detail decayed butts and roots of Sakhalin fir (Abies sachalinensis MAST.) grown in the natural forest in the Tokyo University Forest, Hokkaido.

著者

小山 順二

出版者

北海道大学大学院理学研究院

雑誌

北海道大学地球物理学研究報告 (ISSN:04393503)

巻号頁・発行日

vol.78, pp.53-68, 2015-03-19

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After the 2011 Tohoku-oki megathrust earthquake of Mw 9.0, one of the great concern is whether or not the megathrust earthquake induces large volcanic eruptions and disastrous aftershocks in Japan. There exist 110 active volcanoes in Japan and large eruptions including historical events of each volcano have been compiled in terms of Volcanic Explosivity Index (VEI; Newhall and Self, 1982) from 0 (Non-explosive) to 8 (Mega-colossal). According to “Volcanoes of the World” by Siebert et al. (2010), we could find 50 eruptions in Japan since 600 A.D. classified as VEI 4 (Large) and 5 ~ (Very Large). Speaking about great earthquakes whose earthquake (moment) magnitude M (Mw) is equal to or larger than 8.0, there occurred 34 times since 684 A.D. in Japan. I have compared the time of occurrences of Large volcanic eruptions and large earthquakes (M&gt;7.5) at first, taking examples of Mt. Fuji, Tokachidake, Hokkaido Komagatake and Sakurajima volcanoes. Since I could not find any systematic correlation between them, I decided to compare all the Large (and Very Large) volcanic eruptions and the great earthquakes (M&gt;8.0) in Japan. In order to develop the quantitative discussion, we need to introduce cross-correlogram analysis (Perkel et al., 1967; Grun, 2009) for these two discrete point-processes. All that I could find was very poor correlation between great earthquakes and Large volcanic eruptions in Japan. It is true that many papers have been showing us the correlation between large earthquakes and volcanic eruptions. However, speaking about Large eruptions (not speaking about volcanic disasters), it is not true for the correlation between them. The reason is that some small-scale volcanic activity out of many volcanoes has been activated by great earthquakes almost all the time in the world. Even just after the 2011 Tohoku-oki megathrust, it has been reported that the volcanic activity of about 20 volcanoes in Japan has been enhanced. It is also true that some volcanoes are activated in the present, about 4 years after the megathrust. The evidences should be added, which are the eruptions of Mt. Fuji in 1707 (VEI 5), 49 days after the 1707 Hoei earthquake of M 8.6 and of Bezymianny in Kamchatka in 1956 (VEI 5), 4 years after the 1952 Kamchatka earthquake of Mw 9.2. Both of the volcanoes have spent about 900 ~ 1200 years of quiescence in the volcanic activity. All these would suggest that great earthquakes might induce Large volcanic eruptions nearby, however it is totally dependent on its own potential and preparedness to erupt of each volcano and the earthquakes just play a role of a trigger.

著者

山本 明彦 石川 春義

出版者

北海道大学大学院理学研究科地球惑星科学専攻(地球物理学)

雑誌

北海道大学地球物理学研究報告 (ISSN:04393503)

巻号頁・発行日

vol.65, pp.247-290, 2002-03-25

著者

Hatori Tokutaro

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.47, no.6, pp.1063-1072, 1969-12-20

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The wave source of the tsunami generated off West Hokkaido (Shakotan Peninsula), in the Japan Sea, on Aug. 2, 1940 is estimated by means of an inverse refraction diagram, making use of a new bathymetric chart. The source area extends 170km in the NNW-SSE direction, which is smaller than that obtained by Miyabe (1941). However, the dimension estimated by the present analysis is still large for the earthquake magnitude of M=7.0. From a comparison of the geographic distribution of the earthquake intensity with those of the other tsunamigenic earthquakes that occurred in the Japan Sea, the magnitude of this earthquake is investigated. Effective tsunami height observed on the surrounding coasts of the Japan Sea can be explained by the direction of the present source. Magnitude of the tsunami of 1940 seems to be equal to that of the Niigata tsunami of 1964 and is represented as m=2. Besides, the wave source of the tsunami generated off Rumoi, West Hokkaido, on Nov. 4, 1947 is discussed, taking the aftershock area into consideration.|1940年8月2日,北海道積丹沖に起きた津波は日本海全域に伝播し,北海道西岸をはじめソ連の沿海州と北朝詳,隠岐にも家屋,船舶などに被害を与えた,地震の規模Mは,気象庁の地震カタログ(1958)によるとM=7.0, USCGSによるとMG=7.7と示されており,両者の決定値には著しい違いがある.一方,余震は札幌において多数観測され,P-S頻度分布は10 secから33 secの範囲にあつて,余震域の長さは約190kmと推定されている(宇津,1961)