{"created":"2021-03-01T06:50:47.072228+00:00","id":32145,"links":{},"metadata":{"_buckets":{"deposit":"fb675c34-729c-495e-b489-874702f1dd39"},"_deposit":{"id":"32145","owners":[],"pid":{"revision_id":0,"type":"depid","value":"32145"},"status":"published"},"_oai":{"id":"oai:repository.dl.itc.u-tokyo.ac.jp:00032145","sets":["80:4453:4457","9:504:4455:4458"]},"author_link":["71397","71398","71399","71400","71393","71394","71395","71396"],"item_4_alternative_title_1":{"attribute_name":"その他のタイトル","attribute_value_mlt":[{"subitem_alternative_title":"Construction of an online broadband seismic station in Okinoshima, Kochi prefecture"}]},"item_4_biblio_info_7":{"attribute_name":"書誌情報","attribute_value_mlt":[{"bibliographicIssueDates":{"bibliographicIssueDate":"2015","bibliographicIssueDateType":"Issued"},"bibliographicPageEnd":"14","bibliographicPageStart":"1","bibliographicVolumeNumber":"21","bibliographic_titles":[{"bibliographic_title":"技術研究報告"}]}]},"item_4_description_5":{"attribute_name":"抄録","attribute_value_mlt":[{"subitem_description":"To detect seismic waves from a shallow very low-frequency earthquake, we constructed an online broadband seismic station on the island of Okinoshima, Kochi prefecture. We started with a preliminary investigation on the island. From a preliminary investigation, it was recognized that an Okinoshima elementary school was well suited as the seismic station site. Because a precursory event occurred, we deployed a temporary broadband seismometer on the foundation of the gymnasium of the school. However, the observed horizontal component data included large amplitude noises at low-frequency bands under strong wind conditions. Our interpretation was that the noise was likely caused by the ground motion of soft sediment coupled with vibration of the building structure of the gymnasium. Therefore, we designed a seismic observation station for a broadband seismometer by using a sectional manhole installed in a solid concrete foundation on the base rock. This seismic station was constructed at the edge of the playground of the school. To compare recorded data between the permanent and temporary stations, we performed simultaneous observation for about 1 month. Though the new station was only 100 m away from the temporary station, the vertical and horizontal noise components under strong wind conditions had very small amplitudes at the new station compared with those at the temporary station. In particular, an FFT analysis of the noise of horizontal components at the permanent station indicated that the power across all frequency bands was less than 1/10 that of the temporary station. Therefore, the new station can detect vertical and horizontal seismic waves from shallow very low-frequency earthquakes. In the future, it will be necessary to consider the environmental conditions around the observation location for installing a broadband seismometer. One month after installing the new Okinoshima seismometer, we discovered a small amount of water leakage into the manhole due to a few gaps present at a manhole joint. We filled the gaps with thin acrylic board and strong high-strength adhesive, and no further water leakage was observed. To deal with any problems that arise, periodic inspection after the construction of a seismic station is important.","subitem_description_type":"Abstract"}]},"item_4_description_6":{"attribute_name":"内容記述","attribute_value_mlt":[{"subitem_description":"＜論説＞","subitem_description_type":"Other"}]},"item_4_full_name_3":{"attribute_name":"著者別名","attribute_value_mlt":[{"nameIdentifiers":[{"nameIdentifier":"71397","nameIdentifierScheme":"WEKO"}],"names":[{"name":"TANAKA, Shinichi S."}]},{"nameIdentifiers":[{"nameIdentifier":"71398","nameIdentifierScheme":"WEKO"}],"names":[{"name":"MORI, Takehiko"}]},{"nameIdentifiers":[{"nameIdentifier":"71399","nameIdentifierScheme":"WEKO"}],"names":[{"name":"FUJITA, Chikaaki"}]},{"nameIdentifiers":[{"nameIdentifier":"71400","nameIdentifierScheme":"WEKO"}],"names":[{"name":"OBARA, Kazushige"}]}]},"item_4_identifier_registration":{"attribute_name":"ID登録","attribute_value_mlt":[{"subitem_identifier_reg_text":"10.15083/00032136","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":"AA11602838","subitem_source_identifier_type":"NCID"}]},"item_4_source_id_8":{"attribute_name":"ISSN","attribute_value_mlt":[{"subitem_source_identifier":"13426486","subitem_source_identifier_type":"ISSN"}]},"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":"東京大学地震研究所技術部総合観測室"},{"subitem_text_value":"東京大学地震研究所観測開発基盤センター"},{"subitem_text_value":"Technical Supporting Section for Observational Research, Earthquake Research Institute, the University of Tokyo."},{"subitem_text_value":"Center for Geophysical Observation and Instrumentation, Earthquake Research Institute, the University of Tokyo."}]},"item_creator":{"attribute_name":"著者","attribute_type":"creator","attribute_value_mlt":[{"creatorNames":[{"creatorName":"田中, 伸一"}],"nameIdentifiers":[{"nameIdentifier":"71393","nameIdentifierScheme":"WEKO"}]},{"creatorNames":[{"creatorName":"森, 健彦"}],"nameIdentifiers":[{"nameIdentifier":"71394","nameIdentifierScheme":"WEKO"}]},{"creatorNames":[{"creatorName":"藤田, 親亮"}],"nameIdentifiers":[{"nameIdentifier":"71395","nameIdentifierScheme":"WEKO"}]},{"creatorNames":[{"creatorName":"小原, 一成"}],"nameIdentifiers":[{"nameIdentifier":"71396","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":"2017-06-12"}],"displaytype":"detail","filename":"21_001-014.pdf","filesize":[{"value":"7.1MB"}],"format":"application/pdf","licensetype":"license_note","mimetype":"application/pdf","url":{"label":"21_001-014.pdf","url":"https://repository.dl.itc.u-tokyo.ac.jp/record/32145/files/21_001-014.pdf"},"version_id":"b4cd7915-eafa-4b58-b4cf-2f62a5fe637c"}]},"item_keyword":{"attribute_name":"キーワード","attribute_value_mlt":[{"subitem_subject":"Broadband seismometer","subitem_subject_scheme":"Other"},{"subitem_subject":"Constructed seismic station","subitem_subject_scheme":"Other"},{"subitem_subject":"Low-frequency band noise","subitem_subject_scheme":"Other"},{"subitem_subject":"Sectional type manhole","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":"高知県沖の島におけるオンライン広帯域地震観測点の設置","item_titles":{"attribute_name":"タイトル","attribute_value_mlt":[{"subitem_title":"高知県沖の島におけるオンライン広帯域地震観測点の設置","subitem_title_language":"ja"}]},"item_type_id":"4","owner":"1","path":["4457","4458"],"pubdate":{"attribute_name":"PubDate","attribute_value":"2017-05-15"},"publish_date":"2017-05-15","publish_status":"0","recid":"32145","relation_version_is_last":true,"title":["高知県沖の島におけるオンライン広帯域地震観測点の設置"],"weko_creator_id":"1","weko_shared_id":-1},"updated":"2022-12-19T05:11:10.082695+00:00"}