書誌事項
- タイトル別名
-
- Proximal Deposits of the Usu 2000 Eruption(＜Special Section＞The 2000 Eruption of Usu Volcano (3))
- 有珠火山2000年噴火の火口近傍堆積物
- ウス カザン 2000ネン フンカ ノ カコウ キンボウ タイセキブツ
この論文をさがす
抄録
Events of the March 31, 2000 phreatomagmatic eruption at Usu Volcano can be subdivided into two stages: (1) large-scale black plume stage having 6 major events from 13:07 to 15:28, and (2) relatively small-scale, black plume and jet-type plume stage having 5 major events from 15:28 to 17:07. The total thickness of the March 31 deposit are 100 cm at a site 90 m north from the vent, 9 cm at 550 m NNE from the vent, and 2.5 cm at 1,030 m NE from the vent. The March 31 deposit at the proximal site (90 m north) comprises 10-70 mm thick 20 layers, consisting of sandy coarse 11 layers and sandy to silty matrix-supported 9 layers. The 20 layers at the proximal site can be correlated with each eruption event observed from 13:07 to 17:25 on March 31. In the proximal deposit, essential white pumice ratio is high in the early stage (42%), then the ratio decreases toward the final stage (up to 21%). Essential pumice fragments are white and subrounded, and contain many 0.05-0.2 mm vesicles. The pumice is relatively poorly vesiculated. Grain-size distributions of all layers in the proximal deposit show bimodal distributions, with peaks at -0.5φ to 1φ and 6.5φ to 7.5φ. Poorly-sorted muddy layers are observed in post April 1 deposits. These layers formed during repeated phreatic explosions associated with abundant mud-clast spattering. The proximal area data show that the discharged mass of the March 31 deposit was 2.2×108 kg in total and 1.0×108 kg in the proximal area to 8 mm isopach.
収録刊行物
-
- 火山
-
火山 47 (5), 645-661, 2002
特定非営利活動法人 日本火山学会
- Tweet
詳細情報 詳細情報について
-
- CRID
- 1390001204304604032
-
- NII論文ID
- 10010428817
- 110003041289
-
- NII書誌ID
- AN10512786
-
- ISSN
- 21897182
- 04534360
-
- HANDLE
- 2298/36962
-
- NDL書誌ID
- 6398517
-
- 本文言語コード
- ja
-
- データソース種別
-
- JaLC
- IRDB
- NDL
- CiNii Articles
-
- 抄録ライセンスフラグ
- 使用不可