| Title | Geothermal Investigations of Unzen Volcano, Kyushu, Japan |
|---|---|
| Authors | Y Fujimitsu, S. Ehara, J. Nishijima, H. Shibata, K. Sanematsu, H. Tashiro & T. Daibo |
| Year | 2000 |
| Conference | New Zealand Geothermal Workshop |
| Keywords | |
| Abstract | Geothermal investigation of Unzen Volcano was conducted in 1999 as a part of the Unzen Scientific Drilling Project (USDP). The heat disclxuge rates fkom the lava dome during 5 months obtained by the infrared imagery observation show little variation. The 1-m depth temperatures near the lava dome and the summit of Mt. Fugen are lower thaa an extrapolrrted fine of the temperatures at the stations on the flank of Unzen Volcano. Some intensity anomalies of 2'4Bi and 208Tl were detected at the stations just near the estimated conduit location by the Gmm-ray intensity investigation. In some remote obsemtion of volcanic gases by an F'TIR spectrometer, CO and C02 were detected, and the equilibrium temperature of about 880 "C was estimated from the CO/CO2 ratio. The result of the simulation using a simple 2-0 conductive model showed that non-conductive effects are associated with conduit coolhg, but that there is little possibility of extensive hydrothermal activity near the lava dome. |