{"created":"2021-03-01T06:51:46.401574+00:00","id":33036,"links":{},"metadata":{"_buckets":{"deposit":"7f9f9663-312e-47f3-a5a9-cbec671cc33e"},"_deposit":{"id":"33036","owner":"1","owners":[],"pid":{"revision_id":0,"type":"depid","value":"33036"},"status":"published"},"_oai":{"id":"oai:repository.dl.itc.u-tokyo.ac.jp:00033036","sets":["80:4535:4817:4825","9:504:4538:4819:4826"]},"author_link":["128804","128803"],"item_4_alternative_title_1":{"attribute_name":"その他のタイトル","attribute_value_mlt":[{"subitem_alternative_title":"アリューシャン・アラスカ津波の規模と波源域"}]},"item_4_biblio_info_7":{"attribute_name":"書誌情報","attribute_value_mlt":[{"bibliographicIssueDates":{"bibliographicIssueDate":"1981-08-31","bibliographicIssueDateType":"Issued"},"bibliographicIssueNumber":"1","bibliographicPageEnd":"110","bibliographicPageStart":"97","bibliographicVolumeNumber":"56","bibliographic_titles":[{"bibliographic_title":"東京大學地震研究所彙報 = Bulletin of the Earthquake Research Institute, University of Tokyo"}]}]},"item_4_description_13":{"attribute_name":"フォーマット","attribute_value_mlt":[{"subitem_description":"application/pdf","subitem_description_type":"Other"}]},"item_4_description_5":{"attribute_name":"抄録","attribute_value_mlt":[{"subitem_description":"Based on tide-gauge records of the USCGS and Japanese data, the magnitude and source area of the Aleutian-Alaska tsunamis during the past 42 years are investigated. According to the author's method based on the attenuation of wave-height with distance, the tsunami magnitude (Imamura-Iida scale) of the 1946 Aleutian and 1964 Alaska tsunamis are estimated to be m=3 and 4 respectively. The magnitudes of the 1957 and 1965 Aleutian tsunamis are m=3. According to the empirical formula, the tsunami magnitude is well correlated with seismic moment, but the seismic moment for the 1946 earthquake is considerably small. Its seismic moment may be 1.5 × 1029 dyne-cm judging from the tsunami magnitude. The source area of the 1946 Aleutian tsunami which inferred from an inverse refraction diagram is especially different from the aftershock area. The source area lies on the steep continental slope extending about 400 km between the Unalaska and Unimak Islands. The source area of the 1957 Aleutian tsunami is the largest The length of tsunami source is 900 km which agrees with the aftershockarea. The western part of the source area overlaps about 200 km of the source area of the 1965 tsunami. In the geographic distribution of the tsunami source in the Aleutian-Alaska region, a remarkable gap of the tsunami source is found between the Unimak and Shumagin Islands. Tnis significant segment of 300-400 km may be considered a region of relatively high tsunami risk having the magnitude m=2-3.","subitem_description_type":"Abstract"},{"subitem_description":"最近50年の間に,アリューシャン・アラスカ海域におこった5個の巨大地震に伴った津波について,米国のCGS記録に日本の観測データも加え,津波の規模と波源域を調べ,この海域の津波特性を検討した.まず,各津波の規模(m:今村・飯田スケール)を,震央から島弧にそった沿岸の波高データをもとに,筆者の方法で判定すれば,ハワイに大被害を与えた1946年津波はm=3と格付けされる.この地震のマグニチュードはM=7.4とみなされているが,津波データによれば地震モーメントM0は1.5×1029ダイン・cmと見積もれる.一方これとは対照的に,地震規模が上回った1938年のアラスカ半島沖地震(M=8.3)の津波は,m=2と推定される.そのほか1964年アラスカ津波はm=4,1957年・1965年のアリューシャン津波はm=3と見積もれ,それぞれ地震モーメントに見合った津波であった.各地で観測された津波の伝播時間をもとに,逆伝播図から波源域を推定すると,1964年アラスカ津波の波源域の長さは700kmで,余震域と大体合致する.しかし,1946年津波の波源域は余震域と著しく異なり,ウナラスカ島からウニマク島に至る長さ400kmと推定される.1957年津波の波源域は,余震域とほぼ合致して900kmにもなり,そのほかの津波も日本近海の津波と比べて,波源域は数倍も長い.1964年アラスカ津波では40分の周期が卓越したのに対し,1946年・1957年・1965年津波の周期は10～20分と短かく,波源域が海溝寄りにあったことを暗示している.解析の結果,この50年の間に,各波源域はアッツ島沖からアラスカに至る海域に,島弧にそって並んで分布しているが,アラスカ半島ぞいのウニマク島からシュマーギン島に至る400kmの間に津波の空白域が見出せる.これは,近い将来,この区間にm=2～3クラスの津波発生の可能性が大きいことを考えさせる.","subitem_description_type":"Abstract"}]},"item_4_full_name_3":{"attribute_name":"著者別名","attribute_value_mlt":[{"nameIdentifiers":[{"nameIdentifier":"128804","nameIdentifierScheme":"WEKO"}],"names":[{"name":"羽鳥, 徳太郎"}]}]},"item_4_identifier_registration":{"attribute_name":"ID登録","attribute_value_mlt":[{"subitem_identifier_reg_text":"10.15083/0000033036","subitem_identifier_reg_type":"JaLC"}]},"item_4_publisher_20":{"attribute_name":"出版者","attribute_value_mlt":[{"subitem_publisher":"東京大学地震研究所"}]},"item_4_source_id_10":{"attribute_name":"書誌レコードID","attribute_value_mlt":[{"subitem_source_identifier":"AN00162258","subitem_source_identifier_type":"NCID"}]},"item_4_source_id_8":{"attribute_name":"ISSN","attribute_value_mlt":[{"subitem_source_identifier":"00408972","subitem_source_identifier_type":"ISSN"}]},"item_4_subject_15":{"attribute_name":"日本十進分類法","attribute_value_mlt":[{"subitem_subject":"453","subitem_subject_scheme":"NDC"}]},"item_4_text_21":{"attribute_name":"出版者別名","attribute_value_mlt":[{"subitem_text_value":"Earthquake Research Institute, University of Tokyo"}]},"item_4_text_4":{"attribute_name":"著者所属","attribute_value_mlt":[{"subitem_text_value":"地震研究所"}]},"item_creator":{"attribute_name":"著者","attribute_type":"creator","attribute_value_mlt":[{"creatorNames":[{"creatorName":"Hatori, Tokutaro"}],"nameIdentifiers":[{"nameIdentifier":"128803","nameIdentifierScheme":"WEKO"}]}]},"item_files":{"attribute_name":"ファイル情報","attribute_type":"file","attribute_value_mlt":[{"accessrole":"open_date","date":[{"dateType":"Available","dateValue":"2017-06-26"}],"displaytype":"detail","filename":"ji0561006.pdf","filesize":[{"value":"864.6 kB"}],"format":"application/pdf","licensetype":"license_note","mimetype":"application/pdf","url":{"label":"ji0561006.pdf","url":"https://repository.dl.itc.u-tokyo.ac.jp/record/33036/files/ji0561006.pdf"},"version_id":"b3c59369-47bf-4dfc-886c-c2ed768f13e6"}]},"item_language":{"attribute_name":"言語","attribute_value_mlt":[{"subitem_language":"eng"}]},"item_resource_type":{"attribute_name":"資源タイプ","attribute_value_mlt":[{"resourcetype":"departmental bulletin paper","resourceuri":"http://purl.org/coar/resource_type/c_6501"}]},"item_title":"Tsunami Magnitude and Source Area of the Aleutian-Alaska Tsunamis","item_titles":{"attribute_name":"タイトル","attribute_value_mlt":[{"subitem_title":"Tsunami Magnitude and Source Area of the Aleutian-Alaska Tsunamis","subitem_title_language":"en"}]},"item_type_id":"4","owner":"1","path":["4825","4826"],"pubdate":{"attribute_name":"PubDate","attribute_value":"2008-05-30"},"publish_date":"2008-05-30","publish_status":"0","recid":"33036","relation_version_is_last":true,"title":["Tsunami Magnitude and Source Area of the Aleutian-Alaska Tsunamis"],"weko_creator_id":"1","weko_shared_id":-1},"updated":"2022-12-19T04:08:38.330830+00:00"}