{"created":"2021-03-01T06:51:46.072906+00:00","id":33031,"links":{},"metadata":{"_buckets":{"deposit":"778abcce-acae-409e-9e9e-4e5ff3f5f421"},"_deposit":{"id":"33031","owner":"1","owners":[],"pid":{"revision_id":0,"type":"depid","value":"33031"},"status":"published"},"_oai":{"id":"oai:repository.dl.itc.u-tokyo.ac.jp:00033031","sets":["80:4535:4817:4825","9:504:4538:4819:4826"]},"author_link":["128784","128783"],"item_4_alternative_title_1":{"attribute_name":"その他のタイトル","attribute_value_mlt":[{"subitem_alternative_title":"1980年伊豆半島東方沖の群発地震の活動様式"}]},"item_4_biblio_info_7":{"attribute_name":"書誌情報","attribute_value_mlt":[{"bibliographicIssueDates":{"bibliographicIssueDate":"1981-08-31","bibliographicIssueDateType":"Issued"},"bibliographicIssueNumber":"1","bibliographicPageEnd":"24","bibliographicPageStart":"1","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":"An earthquake swarm activity which occurred in an area off the east coast of the Izu Peninsula during the period from June 24 to July 28, 1980 was studied on the basis of the waveform analysis. This swarm contained many bursts of activity usually lasting for about one hour. The earthquakes which occurred within a certain time interval, e. g. about 15 minutes, exhibit similar waveforms, suggesting that they belong to one \"\"earthquake family\"\". The epicenters of earthquakes in a family are located within a spatial dimension of a few hundred meters with the same mechanism. When the activity of the first family is finished, the second family appears in an adjacent area separated by 1.5 km at most. Four families are usually observed for the activity of about one hour, except for the activity triggered by the M6.7 earthquake. The earthquakes in a given family distribute over the magnitude range from 2.0 to 4.9. The corner frequency of the source spectrum in a given family is almost constant within a range of 15 per cent, and its value depends on the size of the largest earthquake in a family. The largest earthquake usually occurs in the later stage of its sequence. Continuous monitoring of the spectrum therefore will give us some information useful for the prediction of the size of largest earthquake in an earthquake family.","subitem_description_type":"Abstract"},{"subitem_description":"1980年6月24日頃より7月末にかけ,伊豆半島東方沖で最大M6.7を含む顕著な群発地震が発生した.前回の群発地震(1978年,11月-12月)に続き,今回の群発地震についても,活動の活発な時間帯を選び,それらの地震についての波形並びにスペクトル解析から,その活動様式についていくつかの特徴ある結果を得た。主な結果は次の通りである.(1)震源域を囲む5個所のテレメーター観測所の早送り記録(25mm/sec)の重ね合わせにより波形について調べた結果,ある限られた時間帯(例えば15分)に発生する地震は,S-P時間を含め非常に似かよった波形を示し,所謂\"\"相似地震\"\"の集合(Earthquake family)であることが解った.この様な傾向は5個所の観測所すべてについて共通である.(2)一連の相似地震の活動が終ると震源域の移動がみられ,別の相似地震群が得られる.更に活動の継続と共に別の震源域へ移動し,約1時間続いた活動から4種類の相似地震群が得られた.但し,M6.7を持つ最大地震,並びにその直後の地震の活動様式は本震-余震型を示し,相似地震は現われない.(3)S波についてのスペクトル解析から,相似地震のCorner frequencyはM=2.0-4.6の間で略一定であり,その値はその地震群に含まれる最大地震の大きさに依存する.集中した活動をもつ時間帯11組の地震について調べた結果,M6.7の地震系列を除き,約80%のものがいずれかの組に属する相似地震であることが解った.(1),(2),(3)の結果からみて,夫々の相似地震は,ある限られたせまい範囲(数百米),おそらく同じ断層面上で繰返し発生したことが推定される.","subitem_description_type":"Abstract"}]},"item_4_full_name_3":{"attribute_name":"著者別名","attribute_value_mlt":[{"nameIdentifiers":[{"nameIdentifier":"128784","nameIdentifierScheme":"WEKO"}],"names":[{"name":"辻浦, 賢"}]}]},"item_4_identifier_registration":{"attribute_name":"ID登録","attribute_value_mlt":[{"subitem_identifier_reg_text":"10.15083/0000033031","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":"Tsujiura, Masaru"}],"nameIdentifiers":[{"nameIdentifier":"128783","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":"ji0561001.pdf","filesize":[{"value":"1.3 MB"}],"format":"application/pdf","licensetype":"license_note","mimetype":"application/pdf","url":{"label":"ji0561001.pdf","url":"https://repository.dl.itc.u-tokyo.ac.jp/record/33031/files/ji0561001.pdf"},"version_id":"789eae4f-5651-48f5-9d9a-f70b3baeed9a"}]},"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":"Activity Mode of the 1980 Earthquake Swarm Off the East Coast of the Izu Peninsula","item_titles":{"attribute_name":"タイトル","attribute_value_mlt":[{"subitem_title":"Activity Mode of the 1980 Earthquake Swarm Off the East Coast of the Izu Peninsula","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":"33031","relation_version_is_last":true,"title":["Activity Mode of the 1980 Earthquake Swarm Off the East Coast of the Izu Peninsula"],"weko_creator_id":"1","weko_shared_id":-1},"updated":"2022-12-19T04:08:40.822000+00:00"}