{"created":"2023-02-22T08:49:26.863565+00:00","id":2006042,"links":{},"metadata":{"_buckets":{"deposit":"9c9b1843-2243-41d0-85c0-804fe91a1f8c"},"_deposit":{"id":"2006042","owner":"1","owners":[1],"pid":{"revision_id":0,"type":"depid","value":"2006042"},"status":"published"},"_oai":{"id":"oai:repository.dl.itc.u-tokyo.ac.jp:02006042","sets":["80:4535:1674793582205","9:504:4538:1674793533804"]},"author_link":[],"control_number":"2006042","item_4_biblio_info_7":{"attribute_name":"書誌情報","attribute_value_mlt":[{"bibliographicIssueDates":{"bibliographicIssueDate":"2023-03","bibliographicIssueDateType":"Issued"},"bibliographicPageEnd":"32","bibliographicPageStart":"13","bibliographicVolumeNumber":"97","bibliographic_titles":[{"bibliographic_title":"東京大学地震研究所彙報","bibliographic_titleLang":"ja"},{"bibliographic_title":"Bulletin of Earthquake Research Institute, the University of Tokyo","bibliographic_titleLang":"en"}]}]},"item_4_description_5":{"attribute_name":"抄録","attribute_value_mlt":[{"subitem_description":"Microgravity measurements have been conducted in Izu-Oshima volcano by Earthquake Research Institute (ERI), the University of Tokyo and Meteorological Research Institute (MRI), Japan Meteorological Agency in order to investigate subsurface volcanic processes. In 2018, ERI and MRI launched a cooperative observational study to better understand these processes and to apply the data to evaluation of volcanic activity. In the cooperative observation, hybrid absolute and relative gravity measurements were conducted to obtain the absolute gravity changes for the whole island. Further, it was intended for the data to be utilized for constraining instrumental properties such as the scale factor of relative gravimeters. The reading-dependent scale factor for the CG-5#033 relative gravimeter obtained in a previous study was checked using gravity values from the two absolute gravity sites at the volcano as well as additional calibration measurement data from sites of the Japan Gravity Standardization Net 2016. We verified that the scale factor correction worked effectively, so that apparent gravity changes of uncorrected data are sufficiently suppressed, and that the corrected gravity differences coincide well with the reference gravity differences obtained at the absolute gravity sites. The hybrid absolute and relative gravity measurements conducted in November every year from 2018 to 2021 revealed the absolute gravity changes for the whole island. The observed yearly gravity changes reached a maximum of 39 μGals. Relative gravity changes obtained by the CG-5#033 since 2008 show large gravity disturbances of about 80 μGals, particularly between sites with larger altitude differences. Such observed yearly absolute gravity changes and large relative gravity disturbances cannot be explained solely by the free-air effects predicted by GNSS ellipsoidal height changes and －0.3086 mGal/m of vertical gradient of the normal gravity, and are probably caused by infiltration of meteoric water into the volcanic edifice. At the central cone, Mt. Mihara, where continuous subsidence is observed by GNSS, a continuous gravity increase has also been observed. The rate of the observed gravity increase is 6.6-11.1 μGal/year, which is higher than 3.5-3.6 μGal/year, the value predicted by free-air effects. Currently, the cause of such large residual gravity changes is uncertain. Possible causes include gravitational effects by a continuous contractive deformation and mass relocation due to frequent collapses of the crater wall, which occurred at Mt. Mihara, as well as mass addition at depth: specifically, magma intrusion into subsurface void spaces as often reported in basaltic volcanoes.","subitem_description_language":"en","subitem_description_type":"Abstract"}]},"item_4_identifier_registration":{"attribute_name":"ID登録","attribute_value_mlt":[{"subitem_identifier_reg_text":"10.15083/0002006042","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","subitem_publisher_language":"ja"},{"subitem_publisher":"Earthquake Research Institute, The University of Tokyo","subitem_publisher_language":"en"}]},"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":"PISSN"}]},"item_4_text_4":{"attribute_name":"著者所属","attribute_value_mlt":[{"subitem_text_language":"ja","subitem_text_value":"気象庁気象研究所"},{"subitem_text_language":"ja","subitem_text_value":"東京大学地震研究所"},{"subitem_text_language":"ja","subitem_text_value":"気象庁地震火山部"},{"subitem_text_language":"en","subitem_text_value":"Meteorological Research Institute, Japan Meteorological Agency"},{"subitem_text_language":"en","subitem_text_value":"Earthquake Research Institute, The University of Tokyo"},{"subitem_text_language":"en","subitem_text_value":"Seismological and Volcanological Department, Japan Meteorological Agency"}]},"item_creator":{"attribute_name":"著者","attribute_type":"creator","attribute_value_mlt":[{"creatorAffiliations":[{"affiliationNames":[{"affiliationName":"気象庁","affiliationNameLang":"ja"},{"affiliationName":"Japan Meteorological Agency","affiliationNameLang":"en"}]}],"creatorNames":[{"creatorName":"鬼澤, 真也","creatorNameLang":"ja"},{"creatorName":"Onizawa, Shin’ya","creatorNameLang":"en"}]},{"creatorAffiliations":[{"affiliationNames":[{"affiliationName":"東京大学","affiliationNameLang":"ja"},{"affiliationName":"The University of Tokyo","affiliationNameLang":"en"}]}],"creatorNames":[{"creatorName":"西山, 竜一","creatorNameLang":"ja"},{"creatorName":"Nishiyama, Ryuichi","creatorNameLang":"en"}]},{"creatorAffiliations":[{"affiliationNames":[{"affiliationName":"東京大学","affiliationNameLang":"ja"},{"affiliationName":"The University of Tokyo","affiliationNameLang":"en"}]}],"creatorNames":[{"creatorName":"今西, 祐一","creatorNameLang":"ja"},{"creatorName":"Imanishi, Yuichi","creatorNameLang":"en"}]},{"creatorAffiliations":[{"affiliationNames":[{"affiliationName":"東京大学","affiliationNameLang":"ja"},{"affiliationName":"The University of Tokyo","affiliationNameLang":"en"}]}],"creatorNames":[{"creatorName":"大久保, 修平","creatorNameLang":"ja"},{"creatorName":"Okubo, Shuhei","creatorNameLang":"en"}]},{"creatorAffiliations":[{"affiliationNames":[{"affiliationName":"気象庁","affiliationNameLang":"ja"},{"affiliationName":"Japan Meteorological Agency","affiliationNameLang":"en"}]}],"creatorNames":[{"creatorName":"安藤, 忍","creatorNameLang":"ja"},{"creatorName":"Ando, Shinobu","creatorNameLang":"en"}]},{"creatorAffiliations":[{"affiliationNames":[{"affiliationName":"気象庁","affiliationNameLang":"ja"},{"affiliationName":"Japan Meteorological Agency","affiliationNameLang":"en"}]}],"creatorNames":[{"creatorName":"長岡, 優","creatorNameLang":"ja"},{"creatorName":"Nagaoka, Yutaka","creatorNameLang":"en"}]},{"creatorAffiliations":[{"affiliationNames":[{"affiliationName":"気象庁","affiliationNameLang":"ja"},{"affiliationName":"Japan Meteorological Agency","affiliationNameLang":"en"}]}],"creatorNames":[{"creatorName":"島村, 哲也","creatorNameLang":"ja"},{"creatorName":"Shimamura, Tetsuya","creatorNameLang":"en"}]},{"creatorAffiliations":[{"affiliationNames":[{"affiliationName":"気象庁","affiliationNameLang":"ja"},{"affiliationName":"Japan Meteorological Agency","affiliationNameLang":"en"}]}],"creatorNames":[{"creatorName":"平山, 康夫","creatorNameLang":"ja"},{"creatorName":"Hirayama, Yasuo","creatorNameLang":"en"}]},{"creatorAffiliations":[{"affiliationNames":[{"affiliationName":"気象庁","affiliationNameLang":"ja"},{"affiliationName":"Japan Meteorological Agency","affiliationNameLang":"en"}]}],"creatorNames":[{"creatorName":"石原, 昂典","creatorNameLang":"ja"},{"creatorName":"Ishihara,  Takanori","creatorNameLang":"en"}]},{"creatorAffiliations":[{"affiliationNames":[{"affiliationName":"気象庁","affiliationNameLang":"ja"},{"affiliationName":"Japan Meteorological Agency","affiliationNameLang":"en"}]}],"creatorNames":[{"creatorName":"松田, 健助","creatorNameLang":"ja"},{"creatorName":"Matsuda, Kensuke","creatorNameLang":"en"}]},{"creatorAffiliations":[{"affiliationNames":[{"affiliationName":"気象庁","affiliationNameLang":"ja"},{"affiliationName":"Japan Meteorological Agency","affiliationNameLang":"en"}]}],"creatorNames":[{"creatorName":"金子, 祐也","creatorNameLang":"ja"},{"creatorName":"Kaneko, Yuya","creatorNameLang":"en"}]},{"creatorAffiliations":[{"affiliationNames":[{"affiliationName":"気象庁","affiliationNameLang":"ja"},{"affiliationName":"Japan Meteorological Agency","affiliationNameLang":"en"}]}],"creatorNames":[{"creatorName":"上田, 義浩","creatorNameLang":"ja"},{"creatorName":"Ueda, Yoshihiro","creatorNameLang":"en"}]},{"creatorAffiliations":[{"affiliationNames":[{"affiliationName":"気象庁","affiliationNameLang":"ja"},{"affiliationName":"Japan Meteorological Agency","affiliationNameLang":"en"}]}],"creatorNames":[{"creatorName":"谷田部, 史尭","creatorNameLang":"ja"},{"creatorName":"Yatabe, Fumiaki","creatorNameLang":"en"}]},{"creatorAffiliations":[{"affiliationNames":[{"affiliationName":"東京大学","affiliationNameLang":"ja"},{"affiliationName":"The University of Tokyo","affiliationNameLang":"en"}]}],"creatorNames":[{"creatorName":"渡邉, 篤志","creatorNameLang":"ja"},{"creatorName":"Watanabe, Atsushi","creatorNameLang":"en"}]},{"creatorAffiliations":[{"affiliationNames":[{"affiliationName":"東京大学","affiliationNameLang":"ja"},{"affiliationName":"The University of Tokyo","affiliationNameLang":"en"}]}],"creatorNames":[{"creatorName":"安藤, 美和子","creatorNameLang":"ja"},{"creatorName":"Ando, Miwako","creatorNameLang":"en"}]},{"creatorAffiliations":[{"affiliationNames":[{"affiliationName":"東京大学","affiliationNameLang":"ja"},{"affiliationName":"The University of Tokyo","affiliationNameLang":"en"}]}],"creatorNames":[{"creatorName":"坂下, 至功","creatorNameLang":"ja"},{"creatorName":"Sakashita, Shikou","creatorNameLang":"en"}]}]},"item_files":{"attribute_name":"ファイル情報","attribute_type":"file","attribute_value_mlt":[{"accessrole":"open_access","date":[{"dateType":"Available","dateValue":"2023-02-22"}],"displaytype":"detail","filename":"IHO9702.pdf","filesize":[{"value":"8 MB"}],"format":"application/pdf","mimetype":"application/pdf","url":{"objectType":"fulltext","url":"https://repository.dl.itc.u-tokyo.ac.jp/record/2006042/files/IHO9702.pdf"},"version_id":"b6822e5f-3c97-4e02-bf54-eec4ce53478e"}]},"item_keyword":{"attribute_name":"キーワード","attribute_value_mlt":[{"subitem_subject":"gravity measurement","subitem_subject_language":"en","subitem_subject_scheme":"Other"},{"subitem_subject":"Izu-Oshima volcano","subitem_subject_language":"en","subitem_subject_scheme":"Other"},{"subitem_subject":"scale factor","subitem_subject_language":"en","subitem_subject_scheme":"Other"}]},"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":"伊豆大島における火山活動の解明と活動評価への適用に向けた合同重力観測","item_titles":{"attribute_name":"タイトル","attribute_value_mlt":[{"subitem_title":"伊豆大島における火山活動の解明と活動評価への適用に向けた合同重力観測","subitem_title_language":"ja"},{"subitem_title":"Cooperative Gravity Measurements in Izu-Oshima for Revealing Subsurface Volcanic Processes and Application to Evaluation of Volcanic Activities","subitem_title_language":"en"}]},"item_type_id":"4","owner":"1","path":["1674793533804","1674793582205"],"pubdate":{"attribute_name":"PubDate","attribute_value":"2023-02-22"},"publish_date":"2023-02-22","publish_status":"0","recid":"2006042","relation_version_is_last":true,"title":["伊豆大島における火山活動の解明と活動評価への適用に向けた合同重力観測"],"weko_creator_id":"1","weko_shared_id":-1},"updated":"2023-02-27T07:56:54.313962+00:00"}