Drilling to the core of Japan's Unzen Volcano

Setsuya Nakada, Kozo Uto, Sumio Sakuma, John Eichelberger, Hiroshi Shimizu

Research output: Contribution to specialist publicationArticle

Abstract

To understand the structure and growth history of Unzen Volcano in Japan and to clarify the eruption mechanisms of SiO 2-rich viscous magmas, the Unzen Scientific Drilling Project (USDP), a six-year program consisting of two phases, began in April 1999. In the first phase, two holes were drilled into the volcano's flank (USDP-1 and -2 wells). In the second phase, drilling penetrated the magma conduit that fed a lava dome at the summit during the 1991-95 eruption. Through directional drilling, samples of the lava dike believed to have fed the 1991-95 eruption were recovered. The lava dike sample was unexpectedly altered, suggesting that circulation of hydrothermal fluids rapidly cools the conduit region of even very active volcanoes. It is likely that seismic signals monitored before the emergence of lava dome reflected fracturing of the country rocks, caused by veining as volatiles escaped predominantly upward, not outward, from the rising magma.

Original languageEnglish
Pages37-39
Number of pages3
No.120
Specialist publicationGeodrilling International
Publication statusPublished - Mar 1 2006

Fingerprint

Volcanoes
Drilling
Levees
volcano
drilling
Domes
lava dome
volcanic eruption
lava
Directional drilling
dike
magma
country rock
hydrothermal fluid
Rocks
Fluids
well
history
project

All Science Journal Classification (ASJC) codes

  • Geotechnical Engineering and Engineering Geology

Cite this

Nakada, S., Uto, K., Sakuma, S., Eichelberger, J., & Shimizu, H. (2006). Drilling to the core of Japan's Unzen Volcano. Geodrilling International, (120), 37-39.

Drilling to the core of Japan's Unzen Volcano. / Nakada, Setsuya; Uto, Kozo; Sakuma, Sumio; Eichelberger, John; Shimizu, Hiroshi.

In: Geodrilling International, No. 120, 01.03.2006, p. 37-39.

Research output: Contribution to specialist publicationArticle

Nakada, S, Uto, K, Sakuma, S, Eichelberger, J & Shimizu, H 2006, 'Drilling to the core of Japan's Unzen Volcano' Geodrilling International, no. 120, pp. 37-39.
Nakada S, Uto K, Sakuma S, Eichelberger J, Shimizu H. Drilling to the core of Japan's Unzen Volcano. Geodrilling International. 2006 Mar 1;(120):37-39.
Nakada, Setsuya ; Uto, Kozo ; Sakuma, Sumio ; Eichelberger, John ; Shimizu, Hiroshi. / Drilling to the core of Japan's Unzen Volcano. In: Geodrilling International. 2006 ; No. 120. pp. 37-39.
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