{"_buckets": {"deposit": "7fbfe80c-eff2-4aa2-8e46-174b24c890b8"}, "_deposit": {"id": "5363", "owners": [1], "pid": {"revision_id": 0, "type": "depid", "value": "5363"}, "status": "published"}, "_oai": {"id": "oai:nied-repo.bosai.go.jp:00005363", "sets": []}, "author_link": [], "item_10001_biblio_info_7": {"attribute_name": "書誌情報", "attribute_value_mlt": [{"bibliographicIssueDates": {"bibliographicIssueDate": "1995"}, "bibliographicIssueNumber": "5", "bibliographicPageEnd": "328", "bibliographicPageStart": "311", "bibliographicVolumeNumber": "40", "bibliographic_titles": [{"bibliographic_title": "火山", "bibliographic_titleLang": "ja"}, {"bibliographic_title": "BULLETIN OF THE VOLCANOLOGICAL SOCIETY OF JAPAN", "bibliographic_titleLang": "en"}]}]}, "item_10001_description_5": {"attribute_name": "抄録", "attribute_value_mlt": [{"subitem_description": "1991年以来の雲仙岳の噴火活動中に,周期2秒より長い長周期成分を含む火山性微動,A型地震,火砕流に伴う震動,そして爆発地震が観測された.本研究では,主に5月10日の火山性微動と6月11日の爆発的噴火について波形インバージョンにより震源過程を調べた.これらの震動の等価な力源として,シングルフォースあるいは地震モーメントテンソルを用いた.これらの震動を説明する震源モデルを決定するため,震源時間関数を仮定した場合のインバージョンと震源時間関数の関数形を求めるインバージョンの両方を行った.5月10日の微動は,主としてレーリー波で構成されているが,鉛直方向のシングルフォースに比べて震源領域の収縮を表すモーメントテンソルが観測波形をより良く説明した.爆発的噴火に伴う地震もモーメントテンソルの方が観測波形と理論波形の一致が良い.推定された震源時間関数は,初めに震源領域が収縮し3-4秒後に膨張したことを示している.これは爆発が始まってから4秒後に噴火活動が激しくなったことに対応している.爆発地震の震源領域における体積変動量は傾斜変動から推定される体積変動量の約1%と推定される.", "subitem_description_language": "ja", "subitem_description_type": "Other"}, {"subitem_description": "Various types of low-frequency seismic events with predominant periods longer than 2 s have been observed at Unzen volcano since 1991. These events are, in chronological order, low-frequency tremors, A-type volcanic earthquakes, seismic events triggered by pyroclastic flows, and explosion earthquakes. In this study, the source processes of a volcanic tremor episode on May 10 and an explosive eruption on June 11 were investigated by waveform inversion. A vertical single force or a moment tensor were used as equivalent body forces for those events. To determine the appropriate source model for the events, we performed two kinds of inversions : the first is based on assumed source time functions, and the second estimates the shape of the source time functions. The tremor, which is composed mainly of Rayleigh waves, was better explained by a moment tensor representing contraction of the source than a vertical single force. The explosive eruption was also better explained by the moment source. The source time functions we derived indicate that the source first contracted and subsequently expanded about 3-4 s later. This functional dependence may be related to the mass flux of the explosion which culminated about 4 s after the event onset. The volume change of the source region of the explosion earthquake represents only about 1 % of that estimated from measurements of tilt associated with magmatic activity.", "subitem_description_language": "en", "subitem_description_type": "Other"}]}, "item_10001_publisher_8": {"attribute_name": "出版者", "attribute_value_mlt": [{"subitem_publisher": "特定非営利活動法人 日本火山学会", "subitem_publisher_language": "ja"}, {"subitem_publisher": "The Volcanological Society of Japan", "subitem_publisher_language": "en"}]}, "item_10001_relation_14": {"attribute_name": "DOI", "attribute_value_mlt": [{"subitem_relation_type_id": {"subitem_relation_type_id_text": "10.18940/kazan.40.5_311"}}]}, "item_10001_source_id_9": {"attribute_name": "ISSN", "attribute_value_mlt": [{"subitem_source_identifier": "0453-4360", "subitem_source_identifier_type": "ISSN"}]}, "item_creator": {"attribute_name": "著者", "attribute_type": "creator", "attribute_value_mlt": [{"creatorNames": [{"creatorName": "宇平 幸一", "creatorNameLang": "ja"}, {"creatorName": "UHIRA Kohichi", "creatorNameLang": "en"}]}, {"creatorNames": [{"creatorName": "山里 平", "creatorNameLang": "ja"}, {"creatorName": "YAMASATO Hitoshi", "creatorNameLang": "en"}]}, {"creatorNames": [{"creatorName": "橋本 徹夫", "creatorNameLang": "ja"}, {"creatorName": "HASHIMOTO Tetsuo", "creatorNameLang": "en"}]}, {"creatorNames": [{"creatorName": "福井 敬一", "creatorNameLang": "ja"}, {"creatorName": "FUKUI Keiichi", "creatorNameLang": "en"}]}, {"creatorNames": [{"creatorName": "武尾 実", "creatorNameLang": "ja"}, {"creatorName": "TAKEO Minoru", "creatorNameLang": "en"}]}]}, "item_language": {"attribute_name": "言語", "attribute_value_mlt": [{"subitem_language": "eng"}]}, "item_title": "1991年に観測された雲仙岳の長周期地震波動の震源過程 : 5月10日の微動及び6月11日の爆発地震", "item_titles": {"attribute_name": "タイトル", "attribute_value_mlt": [{"subitem_title": "1991年に観測された雲仙岳の長周期地震波動の震源過程 : 5月10日の微動及び6月11日の爆発地震", "subitem_title_language": "ja"}, {"subitem_title": "Source Mechanism of Low-frequency Seismic Events at Unzen Volcano, Kyushu, Japan : Volcanic Tremor on May 10 and Explosion Earthquake on June 11, 1991", "subitem_title_language": "en"}]}, "item_type_id": "40001", "owner": "1", "path": ["1670839190650"], "permalink_uri": "https://nied-repo.bosai.go.jp/records/5363", "pubdate": {"attribute_name": "PubDate", "attribute_value": "2023-03-30"}, "publish_date": "2023-03-30", "publish_status": "0", "recid": "5363", "relation": {}, "relation_version_is_last": true, "title": ["1991年に観測された雲仙岳の長周期地震波動の震源過程 : 5月10日の微動及び6月11日の爆発地震"], "weko_shared_id": -1}