Self-Potential Studies in Volcanic Areas (5)

• Main Authors: White Isl, Takeshi Hashimoto, Tohru Mogj, Yasunori Nishida, Yasuo Ogawa, Naoto Ujihara, Mitsuhiro Oikawa, Masaki Saito, Shoei Mizuhashp
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2004
• Subjects: New Zealand; White Island
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.492.8217; http://eprints.lib.hokudai.ac.jp/dspace/bitstream/2115/8876/1/12(2)_p97-113.pdf

We performed SP profiling or mapping in three volcanic fields, Rishiri (northern Hokkaido), Kusatsu-Shirane (central Honshu) and White Island (northern New Zealand). The SP profile on the western flank of Rishiri volcano showed a remark-able high in the summit side, which is similar to many other active volcanoes. Assuming a negative s-potential, it is likely that Rishiri volcano has a large hydroth-ermal circulation system, and therefore, still has enough thermal energy to maintain this circulation. Kusatsu-Shirane volcano inversely showed a decreasing trend toward the summit. It is a contradictive result to the previous knowledge that a volcano with remarkable hydrothermal system shows negative SP on the top. We suspect that the low pH of ground water in this area makes s-potential null or positive, resulting in the reversed surface SP profile to ordinary cases. This idea