書誌事項
- タイトル別名
-
- Positioning of Magma Reservoir at Unzen Volcano by GPS Survey
- GPS ソクリョウ ニヨル ウンゼン カザン ノ マグマ タマリ ノ スイテイ
この論文をさがす
説明
Unzen volcano located at Shimabara Peninsula, Kyushu, Japan, has been erupted at the summit since November 1990 after 198 years dormant period. Phreatic eruption continued until middle of May 1991, and the appearance of a lava dome was confirmed on May 20, 1991. Since the end of May 1991, the lava dome has been growing, and pyroclastic flows have been frequently generated by collapses of the dome. Total volume of discharged lava as of February 1994 is estimated to be 1.86×10^8m3 by Geographical Survey Institute. GPS surveys have been repeated at several sites around the volcano since January 1991. Until the middle of 1991, the ground around the volcano indicated expansion and then turned into contraction. Applying a point source model to the data on the change in length of GPS baselines, the location of a pressure source is estimated to be approximately 5 km west from the summit and approximately 11 km in depth. Dilatation of the ground in the area which includes the pressure source region closely relates to changes in extrusion rate of lava. While the rate exceeded about 1×105 m3/day, the ground indicated deflation, and in contrast, the contractive movement came to stay when the rate decreased to less than the value. This suggests continuous supply of magma through the lower crust to the zone where the pressure source is located. These results are consistent with those derived from levelling survey. It is concluded that the location of the pressure source estimated here indicates that of the magma reservoir.
収録刊行物
-
- 火山
-
火山 40 (1), 43-51, 1995
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
- 1390001204304172288
-
- NII論文ID
- 110003041026
- 10019366230
-
- NII書誌ID
- AN10512786
-
- ISSN
- 21897182
- 04534360
-
- NDL書誌ID
- 3624077
-
- 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