Seismicity controlled by resistivity structure: The 2016 Kumamoto earthquakes, Kyushu Island, Japan
| Autor: | Takeshi Hashimoto, Takao Koyama, Taro Shiotani, Koki Aizawa, Yuko Tsukashima, Wataru Kanda, Yusuke Yamashita, Kanade Takashima, Makoto Uyeshima, Hiroshi Shimizu, Ryokei Yoshimura, Nobuo Matsushima, Manami Nakamoto, Shinichi Takakura, Kaori Tsukamoto, Hiroyuki Inoue, Asuma Wakabayashi, Shiori Fujita, Azusa Shito, Satoshi Matsumoto, Mitsuru Utsugi, Makoto Tamura, Kazunari Uchida, Kenichi Yamazaki, Takeshi Matsushima, Shintaro Komatsu, Kentaro Kondo, Maki Hata, Katsuaki Koike, Tohru Yoshinaga, Hisafumi Asaue, Masahiro Miyazaki |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
2016 Kumamoto earthquake
Futagawa fault 010504 meteorology & atmospheric sciences Median Tectonic Line Hinagu fault Aso volcano Tsurumi volcano Induced seismicity 010502 geochemistry & geophysics 01 natural sciences Kuju volcano Magnetotellurics Electrical resistivity and conductivity Aftershock 0105 earth and related environmental sciences Resistivity structure geography geography.geographical_feature_category Electrically conductive Geology Geophysics Volcano Space and Planetary Science Structural control Epicenter Seismology Electric resistivity |
| Zdroj: | Earth, Planets and Space. 69(No. 1) |
| Popis: | The M JMA 7.3 Kumamoto earthquake that occurred at 1:25 JST on April 16, 2016, not only triggered aftershocks in the vicinity of the epicenter, but also triggered earthquakes that were 50–100 km away from the epicenter of the main shock. The active seismicity can be divided into three regions: (1) the vicinity of the main faults, (2) the northern region of Aso volcano (50 km northeast of the mainshock epicenter), and (3) the regions around three volcanoes, Yufu, Tsurumi, and Garan (100 km northeast of the mainshock epicenter). Notably, the zones between these regions are distinctively seismically inactive. The electric resistivity structure estimated from one-dimensional analysis of the 247 broadband (0.005–3000 s) magnetotelluric and telluric observation sites clearly shows that the earthquakes occurred in resistive regions adjacent to conductive zones or resistive-conductive transition zones. In contrast, seismicity is quite low in electrically conductive zones, which are interpreted as regions of connected fluids. We suggest that the series of the earthquakes was induced by a local accumulated stress and/or fluid supply from conductive zones. Because the relationship between the earthquakes and the resistivity structure is consistent with previous studies, seismic hazard assessment generally can be improved by taking into account the resistivity structure. Following on from the 2016 Kumamoto earthquake series, we suggest that there are two zones that have a relatively high potential of earthquake generation along the western extension of the MTL. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|