| Autor: |
Satoru Tanaka, Hiroki Miyamachi, Yutaka Hayashi, Jun Oikawa, Sosuke Yamaguchi, Kiyoshi Nishi, Hiroyuki Hamaguchi, Sadato Ueki, Haruhisa Nakamichi, Teruo Yamawaki, Hiroshi Shimizu, Tomoki Tsutsui, Hitoshi Yamasato, Takeshi Nishimura |
| Rok vydání: |
2004 |
| Předmět: |
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| Zdroj: |
Journal of Volcanology and Geothermal Research. 138:267-282 |
| ISSN: |
0377-0273 |
| DOI: |
10.1016/j.jvolgeores.2004.07.010 |
| Popis: |
The three-dimensional P-wave velocity structure of the Bandai volcano has been revealed by tomographic inversion using approximately 2200 travel-time data collected during an active seismic survey comprising 298 temporary seismic stations and eight artificial shots. The key result of this study is the delineation of a high-velocity anomaly (Vp>4.6 km/s at sea-level) immediately below the summit peak. This feature extends to depths of 1–2 km below sea-level. The near-surface horizontal position of the high-velocity anomaly coincides well with that of a positive Bouguer gravity anomaly. Geological data demonstrate that sector collapses have occurred in all directions from the summit and that the summit crater has been repeatedly refilled with magmatic material. These observations suggest that the high-velocity region revealed in this study is a manifestation of an almost-solidified magmatic plumbing system. We have also noted that a near-surface low-velocity region (Vp |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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Full Text from ScienceDirect