論文

査読有り
2013年

Conduit process in vulcanian eruptions at Sakurajima volcano, Japan: Inference from comparison of volcanic ash with pressure wave and seismic data

Bulletin of Volcanology
  • T. Miwa
  • ,
  • A. Toramaru

75
1
開始ページ
1
終了ページ
13
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.1007/s00445-012-0685-y
出版者・発行元
Springer Science and Business Media LLC

To elucidate the conduit processes controlling the amplitude of air pressure waves (Apw) from vulcanian eruptions at the Sakurajima volcano, Japan, we examine ash particles emitted by eruptions preceded by swarms of low-frequency B-type earthquakes (BL-swarms). We measure the water content of glassy ash, an indicator of shallow magma storage pressure, and vesicle textures, such as vesicle number density (VND). These data allow us to reconstruct the shallow conduit by comparing vesicularity with inferred pressure, and therefore depth, of magma storage. The results show that VND increases with depth, implying formation of a dense, outgassed magma cap underlain by more-vesicular, less-outgassed, magma. The VND and water content in the glassy ash positively correlate with the duration of BL-swarms, suggesting that such seismic signals reflect upward migration of deep gas- and vesicle-rich magma. Finally, it is determined that Apw positively correlates with VND, suggesting that the amplitude of the air pressure waves is controlled by the amount of accumulated gas- and bubble-rich magma below the dense magma cap. © 2013 Springer-Verlag Berlin Heidelberg.

リンク情報
DOI
https://doi.org/10.1007/s00445-012-0685-y
URL
http://link.springer.com/content/pdf/10.1007/s00445-012-0685-y.pdf
URL
http://link.springer.com/article/10.1007/s00445-012-0685-y/fulltext.html
URL
http://link.springer.com/content/pdf/10.1007/s00445-012-0685-y

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