Abstract
To elucidate the conduit processes controlling the amplitude of air pressure waves (A pw ) 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 A pw 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.
| Original language | English |
|---|---|
| Pages (from-to) | 1-13 |
| Number of pages | 13 |
| Journal | Bulletin of Volcanology |
| Volume | 75 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - Jan 9 2013 |
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All Science Journal Classification (ASJC) codes
- Geochemistry and Petrology
Cite this
Conduit process in vulcanian eruptions at Sakurajima volcano, Japan : Inference from comparison of volcanic ash with pressure wave and seismic data. / Miwa, T.; Toramaru, Atsushi.
In: Bulletin of Volcanology, Vol. 75, No. 1, 09.01.2013, p. 1-13.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Conduit process in vulcanian eruptions at Sakurajima volcano, Japan
T2 - Inference from comparison of volcanic ash with pressure wave and seismic data
AU - Miwa, T.
AU - Toramaru, Atsushi
PY - 2013/1/9
Y1 - 2013/1/9
N2 - To elucidate the conduit processes controlling the amplitude of air pressure waves (A pw ) 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 A pw 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.
AB - To elucidate the conduit processes controlling the amplitude of air pressure waves (A pw ) 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 A pw 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.
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U2 - 10.1007/s00445-012-0685-y
DO - 10.1007/s00445-012-0685-y
M3 - Article
VL - 75
SP - 1
EP - 13
JO - Bulletin of Volcanology
JF - Bulletin of Volcanology
SN - 0258-8900
IS - 1
ER -