{"created":"2021-03-01T06:51:31.004147+00:00","id":32805,"links":{},"metadata":{"_buckets":{"deposit":"5d0452d4-498c-427c-8efb-11b642f00cdd"},"_deposit":{"id":"32805","owner":"1","owners":[],"pid":{"revision_id":0,"type":"depid","value":"32805"},"status":"published"},"_oai":{"id":"oai:repository.dl.itc.u-tokyo.ac.jp:00032805","sets":["80:4535:4737:4743","9:504:4538:4739:4744"]},"author_link":["127703","127704","127705","127706","127707","127698","127699","127700","127701","127702"],"item_4_alternative_title_1":{"attribute_name":"その他のタイトル","attribute_value_mlt":[{"subitem_alternative_title":"Seismological Study Based on Recently Installed Permanent Stations and a Small Eruptive Event on January 6, 1989 at Kusatsu-Shirane Volcano"}]},"item_4_biblio_info_7":{"attribute_name":"書誌情報","attribute_value_mlt":[{"bibliographicIssueDates":{"bibliographicIssueDate":"1989-09-30","bibliographicIssueDateType":"Issued"},"bibliographicIssueNumber":"2","bibliographicPageEnd":"345","bibliographicPageStart":"325","bibliographicVolumeNumber":"64","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":"火山噴火予知計画の一環として,地震研究所では,草津白根山の湯釜,涸釜,水釜火口の周囲に,6観測点からなる常設的な火山観測網を展開した.観測の中心は地震動であるが,地中温度,噴気温度,電気伝導度についても,連続観測を試行している.観測データは,無線テレメータにより,東京の地震研究所まで常時伝送される.地震研究所で受信したデータは,富士山や伊豆大島のデータと一緒に,ミニコンピュータにより,リアル・タイムで処理される.地震動のデータは,先ず振巾のレベルにより,次にノイズレベルや着震時刻も考慮して,地震かどうかの判定がなされる.更に,周辺の広域徴小地震観測網のデータと比較して,火山内部の地震かどうかが判断される.震源はオフラインで計算され,データに最もフィットするP波速度として2.5km/sが得られた.草津白根山では,1988年9月末から10月にかけて,火山性地震がやや群発的に発生した.その震源は,水釜火口南東部に集中した.その後,地震の震源は浅くなり,ほぼ同じ地点で間欠的な火山性微動が活発化した.1989年1月6日になると,連続的な微動が湯釜火口付近で起こり,24時間近くも継続した.それに伴って,湯釜火口の北西火口壁の付近の湖面下で,熱水か水蒸気(又は水蒸気を主体とする火山ガス)の急激な噴出があり,若干の火山灰が火口湖面およびその近傍に散布された.この小噴火の後には,震源が水釜火口南東部に集中する傾向は弱まった.水釜火口の南東部における火山性地震と火山性微動の活動は,マグマや水蒸気の移動と対応し,1月6日の小噴火の準備過程であったと推定される.","subitem_description_type":"Abstract"},{"subitem_description":"A permanent network system for observations of volcanic activities have been installed in the vicinity of the Yugama, Karegama and Mizugama craters of Kusatsu-Shirane volcano. The system provides seismological data as well as preliminary results of continuous observations of underground temperatures, fumarolic temperatures and underground electric conductivities. All the data are continuously transmitted to the Earthquake Research Institute by a radio-wave telemetering system. The data are subject to real time processing in a mini-computer along with data of Fuji and Izu-Oshima volcanoes. Seismic events are first picked up, based on the amplitude level of the ground motions, and then examined in more detail, taking into account the noise levels, the arrival times and whether it occurred inside or outside the volcanic area. In the calculation of hypocenters, a P-wave seismic velocity of 2.5 km/s, which is best fit to the arrival times of the seismic waves, is assumed. Swarm-like seismic activity was observed from the end of September through October, 1988 at Kusatsu-Shirane volcano. Most of the determined hypocenters during this activity were concentrated below a specific point southeast of the Mizugama crater. In the following period, hypocenters were shifted to the shallower part of the same area, and the episodic volcanic tremors were more frequent. On January 6, 1989, a continuous volcanic tremor suddenly occurred and lasted for almost 24 hours. This tremor was accompanied by a silent extrusion of hot steam or water at the northwest part of Yugama crater with a small amount of volcanic ash distributed over the Yugama crater lake. After this small eruptive event, the hypocenters of volcanic earthquakes became more scattered. It is inferred that the volcanic earthquakes and tremors centered southeast of the Mizugama crater reflect the underground migration of magma or hot steam, and were precursors of the eruptive event on January 6.","subitem_description_type":"Abstract"}]},"item_4_full_name_3":{"attribute_name":"著者別名","attribute_value_mlt":[{"nameIdentifiers":[{"nameIdentifier":"127703","nameIdentifierScheme":"WEKO"}],"names":[{"name":"Ida, Y."}]},{"nameIdentifiers":[{"nameIdentifier":"127704","nameIdentifierScheme":"WEKO"}],"names":[{"name":"Osada, N."}]},{"nameIdentifiers":[{"nameIdentifier":"127705","nameIdentifierScheme":"WEKO"}],"names":[{"name":"Sawaa, M."}]},{"nameIdentifiers":[{"nameIdentifier":"127706","nameIdentifierScheme":"WEKO"}],"names":[{"name":"Koyama, E."}]},{"nameIdentifiers":[{"nameIdentifier":"127707","nameIdentifierScheme":"WEKO"}],"names":[{"name":"Kagiyama, T."}]}]},"item_4_identifier_registration":{"attribute_name":"ID登録","attribute_value_mlt":[{"subitem_identifier_reg_text":"10.15083/0000032805","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":"井田, 喜明"}],"nameIdentifiers":[{"nameIdentifier":"127698","nameIdentifierScheme":"WEKO"}]},{"creatorNames":[{"creatorName":"長田, 昇"}],"nameIdentifiers":[{"nameIdentifier":"127699","nameIdentifierScheme":"WEKO"}]},{"creatorNames":[{"creatorName":"沢田, 宗久"}],"nameIdentifiers":[{"nameIdentifier":"127700","nameIdentifierScheme":"WEKO"}]},{"creatorNames":[{"creatorName":"小山, 悦郎"}],"nameIdentifiers":[{"nameIdentifier":"127701","nameIdentifierScheme":"WEKO"}]},{"creatorNames":[{"creatorName":"鍵山, 恒臣"}],"nameIdentifiers":[{"nameIdentifier":"127702","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":"ji0642010.pdf","filesize":[{"value":"1.5 MB"}],"format":"application/pdf","licensetype":"license_note","mimetype":"application/pdf","url":{"label":"ji0642010.pdf","url":"https://repository.dl.itc.u-tokyo.ac.jp/record/32805/files/ji0642010.pdf"},"version_id":"3142d2db-2dba-44f8-ad31-01626c2b5ca4"}]},"item_language":{"attribute_name":"言語","attribute_value_mlt":[{"subitem_language":"jpn"}]},"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":"草津白根山における常設地震観測と1989年1月6日の小噴火","item_titles":{"attribute_name":"タイトル","attribute_value_mlt":[{"subitem_title":"草津白根山における常設地震観測と1989年1月6日の小噴火","subitem_title_language":"ja"}]},"item_type_id":"4","owner":"1","path":["4743","4744"],"pubdate":{"attribute_name":"PubDate","attribute_value":"2008-05-30"},"publish_date":"2008-05-30","publish_status":"0","recid":"32805","relation_version_is_last":true,"title":["草津白根山における常設地震観測と1989年1月6日の小噴火"],"weko_creator_id":"1","weko_shared_id":-1},"updated":"2022-12-19T05:29:37.974887+00:00"}