火山灰粒子組成の側方・垂直変化から見た入戸火砕流の堆積機構
スポンサーリンク
概要
- 論文の詳細を見る
The Ito pyroclastic flow was erupted from the Aira Caldera 25,000 years ago and emplaced in a wide area of the Southern Kyushu district. This one of the large-scale pyroclastic flow deposits in the late Quaternary Japanese Islands, is mostly massive with no distinct internal flow boundaries. A component analysis of the coarse ash fraction (2-0.25 mm in diameter), however, shows that lithic fragments and crystals decrease and glass fragments increase outward from the caldera center to distal areas and downward from the upper part to lower part of the single flow unit. Density differences of particles may cause the lateral variation but cannot account for the vertical variation. Provided a single steady eruption, the lateral and vertical variations probably reflects the temporal changes the proportion of the ejected components and particle-by-particle emplacement from the sustained turbulent pyroclastic flow.
- 特定非営利活動法人日本火山学会の論文
- 2001-11-20
著者
関連論文
- 凝集粒子を用いた噴煙高度の推定 : 浅間火山2004年9月23日噴火に伴う降下火砕物の堆積様式(2004年浅間山噴火(2))
- P51 火砕物粒子の気泡形態から推定するマグマの発泡・破砕機構 : 姶良カルデラ・入戸火砕流堆積物における例
- 火山灰粒子組成の側方・垂直変化から見た入戸火砕流の堆積機構