Electrical conductive fluid-rich zones and their influence on the earthquake initiation, growth, and arrest processes: observations from the 2016 Kumamoto earthquake sequence, Kyushu Island, Japan

Autor: Koki Aizawa, Shinichi Takakura, Hisafumi Asaue, Katsuaki Koike, Ryokei Yoshimura, Ken’ichi Yamazaki, Shintaro Komatsu, Mitsuru Utsugi, Hiroyuki Inoue, Kaori Tsukamoto, Makoto Uyeshima, Takao Koyama, Wataru Kanda, Tohru Yoshinaga, Nobuo Matsushima, Kazunari Uchida, Yuko Tsukashima, Takeshi Matsushima, Hiroshi Ichihara, Dan Muramatsu, Yoshiko Teguri, Azusa Shito, Satoshi Matsumoto, Hiroshi Shimizu
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Zdroj: Earth, Planets and Space, Vol 73, Iss 1, Pp 1-12 (2021)
Druh dokumentu: article
ISSN: 1880-5981
DOI: 10.1186/s40623-020-01340-w
Popis: Abstract Crustal earthquake ruptures tend to initiate near fluid-rich zones. However, it is relatively unknown whether fluid-rich zones can further promote or arrest these ruptures. We image the electrical resistivity structure around the focal area of the 2016 Kumamoto earthquake sequence by using 200 sites broadband magnetotelluric data, and discuss its quantitative relationship to earthquake initiation, growth, and arrest processes. The ruptures that initiated along the outer edge of the low-resistivity fluid-rich zones ( 400 °C) fluid-rich zones, whereas shallower low-temperature (200–400 °C) fluid-rich zones either promoted or arrested the ruptures. These results suggest that the distribution of mid-crustal fluids contributes to the initiation, growth, and arrest of crustal earthquakes. The pre-failure pressure/temperature gradient (spatial difference) of the pore fluids may contribute to the rupture initiation, propagation, and arrest.
Databáze: Directory of Open Access Journals
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