{"_buckets": {"deposit": "5096d5ad-8128-4415-b2f8-548a514ea572"}, "_deposit": {"created_by": 7, "id": "7030", "owners": [7], "pid": {"revision_id": 0, "type": "depid", "value": "7030"}, "status": "published"}, "_oai": {"id": "oai:nied-repo.bosai.go.jp:00007030", "sets": []}, "author_link": [], "item_10001_biblio_info_7": {"attribute_name": "書誌情報", "attribute_value_mlt": [{"bibliographicIssueDates": {"bibliographicIssueDate": "2021", "bibliographicIssueDateType": "Issued"}, "bibliographicPageStart": "122", "bibliographicVolumeNumber": "68", "bibliographic_titles": [{"bibliographic_title": "日本地球化学会年会要旨集", "bibliographic_titleLang": "ja"}, {"bibliographic_title": "Abstracts of Annual Meeting of the Geochemical Society of Japan", "bibliographic_titleLang": "en"}]}]}, "item_10001_description_5": {"attribute_name": "抄録", "attribute_value_mlt": [{"subitem_description": "希ガスは化学的に不活性であり、その存在量比は物理的過程のみによって変動するため、火山噴気中の組成変動は比較的単純である。また、噴気中の3Heと40Ar*(40Arの大気Arからの過剰量)はほぼ全てマグマ起源であるため、噴気の3He/40Ar*の変動はマグマ起源He/Arの変動を直接反映する。2015年から継続的に白根山北側噴気群の希ガス・CO2の濃度・同位体組成の測定を行ったところ、2018年5月以降、3He/4Heと3He/CO2が上昇し、マグマ起源ガス(高3He/4He、高3He/CO2)の供給量が増加したことが示唆された。また、噴気中の3He/40Ar*は3He/4Heと連動して顕著に上昇した。マグマから脱ガスするHe/Arはマグマ発泡度の増加に伴い上昇することから、草津白根山噴気中の3He/40Ar*の上昇はマグマ発泡度の増加を示唆する。すなわち、噴気中の3He/40Ar*はマグマ活動の状態を評価する上で重要な指標となりうる。", "subitem_description_language": "ja", "subitem_description_type": "Other"}, {"subitem_description": "Since noble gases are chemically inert and their abundance ratios vary only by physical processes, compositional variations in volcanic gases are relatively simple. Variations in 3He/40Ar* ratios (40Ar* = 40Ar excess from atmospheric Ar) of fumarolic gases reflect variations in magmatic He/Ar ratios because both 3He and 40Ar* of fumarolic gases are mostly magmatic in origin. We have measured the concentrations and isotopic compositions of noble gases and CO2 of fumarolic gases collected on the north side of Mt. Shirane since 2015. As a result, the 3He/4He and 3He/CO2 ratios increased after May 2018, suggesting an increase in the supply of magmatic gas with high 3He/4He and 3He/CO2 ratios. The 3He/40Ar* ratios of the fumarolic gases significantly increased when the 3He/4He ratios were high. It has been suggested that He/Ar ratios in gas phases of magma increase with increasing magma vesicularity. Thus, the increase in the 3He/40Ar* ratios suggests an increase in magma vesicularity at the Kusatsu-Shirane volcano. In summary, 3He/40Ar* ratios of fumarolic gases might be an important indicator to evaluate a state of magma.", "subitem_description_language": "en", "subitem_description_type": "Other"}]}, "item_10001_publisher_8": {"attribute_name": "出版者", "attribute_value_mlt": [{"subitem_publisher": "一般社団法人日本地球化学会", "subitem_publisher_language": "ja"}, {"subitem_publisher": "GEOCHEMICAL 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": "10.14862/geochemproc.68.0_122"}}]}, "item_creator": {"attribute_name": "著者", "attribute_type": "creator", "attribute_value_mlt": [{"creatorNames": [{"creatorName": "小長谷 智哉", "creatorNameLang": "ja"}, {"creatorName": "Obase Tomoya", "creatorNameLang": "en"}]}, {"creatorNames": [{"creatorName": "角野 浩史", "creatorNameLang": "ja"}, {"creatorName": "Sumino Hirochika", "creatorNameLang": "en"}]}, {"creatorNames": [{"creatorName": "外山 浩太郎", "creatorNameLang": "ja"}, {"creatorName": "Toyama Kotaro", "creatorNameLang": "en"}]}, {"creatorNames": [{"creatorName": "大場 武", "creatorNameLang": "ja"}, {"creatorName": "Ohba Takeshi", "creatorNameLang": "en"}]}, {"creatorNames": [{"creatorName": "谷口 無我", "creatorNameLang": "ja"}, {"creatorName": "Yaguchi Muga", "creatorNameLang": "en"}]}, {"creatorNames": [{"creatorName": "寺田 暁彦", "creatorNameLang": "ja"}, {"creatorName": "Terada Akihiko", "creatorNameLang": "en"}]}]}, "item_language": {"attribute_name": "言語", "attribute_value_mlt": [{"subitem_language": "jpn"}]}, "item_title": "草津白根山噴気中のマグマ起源ヘリウム・アルゴン比の時間変動", "item_titles": {"attribute_name": "タイトル", "attribute_value_mlt": [{"subitem_title": "草津白根山噴気中のマグマ起源ヘリウム・アルゴン比の時間変動", "subitem_title_language": "ja"}, {"subitem_title": "Temporal variation in the ratio of magmatic helium and argon in fumarolic gases at Kusatsu-Shirane volcano", "subitem_title_language": "en"}]}, "item_type_id": "40001", "owner": "7", "path": ["1670839190650"], "permalink_uri": "https://nied-repo.bosai.go.jp/records/7030", "pubdate": {"attribute_name": "PubDate", "attribute_value": "2025-03-31"}, "publish_date": "2025-03-31", "publish_status": "0", "recid": "7030", "relation": {}, "relation_version_is_last": true, "title": ["草津白根山噴気中のマグマ起源ヘリウム・アルゴン比の時間変動"], "weko_shared_id": -1}