岩手火山，一本木原岩屑なだれ堆積物の¹⁴Cウィグルマッチング年代と崩壊堆積物の特徴：活火山における小規模な表層崩壊堆積物

• 伊藤 順一

  国立研究開発法人 産業技術総合研究所 地質調査総合センター 活断層・火山研究部門

書誌事項

タイトル別名

• Radiocarbon Wiggle-matching Age and Depositional Characteristics of the Ippongihara Debris Avalanche Deposit, Iwate Volcano: An Example of a Small-scale (<0.1km³) Debris Avalanche Deposit Induced by Flank Collapse on an Active Volcano
• 岩手火山,一本木原岩屑なだれ堆積物の¹⁴Cウィグルマッチング年代と崩壊堆積物の特徴 : 活火山における小規模な表層崩壊堆積物
• イワテ カザン,イッポン キハラ ガンセツナダレ タイセキブツ ノ ¹ ⁴ Cウィグルマッチング ネンダイ ト ホウカイ タイセキブツ ノ トクチョウ : カッカザン ニ オケル ショウキボ ナ ヒョウソウ ホウカイ タイセキブツ

抄録

Hazard evaluation of the Ippongihara Debris Avalanche Deposit (Di), which is the most recent slope failure deposit at Iwate Volcano, NE Japan, requires a careful and precise assessment of the age and characteristics of the deposit. Geological and geomorphological investigations have yielded a volume of ca. 4.6×10⁷m³, a travel distance of ca. 8km, and an elevation change of ca. 1.6km. AMS radiocarbon dating was carried out on a buried tree trunk sample that was recovered from the deposit. The trunk displayed 83 annual tree-ring layers, which allowed eight ¹⁴C ages for the outer 3 annual layers of the tree trunk. Using the IntCal 13 calibration curve, the wiggle-matching method was applied to the age data and provided a suitable and consistent age of cal. AD 1333-1346 (95.4%), with the exclusion of the sample for the outermost sample. While the hummocky surface is not observed for Di, a block facies composed of unconsolidated tephra and paleosol units is recognized for this deposit. Internal facies of the debris avalanche blocks include 1) minor normal-faults observed as offset tephra layers caused by stretched deformation during sliding on the volcano slope, and 2) repetitions of tephra layers caused by compressional deformation during the depositional processes. The features indicate that Di is a ridged and extensional type of debris avalanche deposit. Di was formed by the flank collapse of a wide area of the volcano, but the trigger of this avalanche remains unclear.

収録刊行物

• 火山

  火山 64 (3), 153-167, 2019-09-30

  特定非営利活動法人 日本火山学会

キーワード

• Iwate Volcano
• Ippongihara
• ¹⁴C Wiggle matching
• slope failure
• debris avalanche
• rockslide avalanche

詳細情報

• CRID: 1390001277368952192
• NII論文ID: 130007728677
• NII書誌ID: AN10512786
• DOI: 10.18940/kazan.64.3_153
• ISSN: 21897182
• ISSN: 04534360
• NDL書誌ID: 029999470
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I029999470
• 本文言語コード: ja
• データソース種別:
  • JaLC
  • NDL
  • CiNii Articles
• 抄録ライセンスフラグ: 使用不可