TY - JOUR
T1 - Fault model of the 1804 Kisakata earthquake (Akita, Japan)
AU - Imai, Kentaro
AU - Okada, Shinsuke
AU - Takahashi, Narumi
AU - Ebina, Yuichi
AU - Tsuji, Yoshinobu
N1 - Funding Information:
The authors are grateful to Editor Allison Bent, Guest Editors Paola Albini and Kenji Satake, and two anonymous reviewers for their constructive and attentive comments. This research was supported by Grant-in-Aid for Scientific Research (B) Number 16H03146 from the Japan Society for the Promotion of Science. The Geospatial Information Authority of Japan (GSI) provided the authors with the aerial map, the Inozu map, and the 1 m digital elevation model (DEM) around the Kisakata area.
Publisher Copyright:
© 2020 Seismological Society of America.
PY - 2020/9
Y1 - 2020/9
N2 - The 10 July 1804 Kisakata earthquake occurred offshore Kisakata (Akita, Japan), and widespread felt shaking was reported from Matsumae (Hokkaido) to OhmiHachiman (Shiga Prefecture). The earthquake caused strong ground motions that extensively damaged areas near the epicenter, such as along the coast of Kisakata, and the resultant tsunami caused extensive damage along the coast from Kisakata to Sakata. Furthermore, Kisakata lagoon was uplifted by dislocation during the earthquake, exposing the lagoon floor. Here, we performed a field survey of the uplift distribution based on microtopographic remnants of the former shoreline of Kisakata lagoon and used historical documents to re-evaluate tsunami trace heights. Using ocean-bottom reflection profiles, we estimated a fault model for the earthquake and resultant tsunami. Our model indicates that an average of 5.6 m of slip on the fault (equivalent to an Mw 7.1 earthquake) is required to explain the observed crustal deformation and tsunami height distributions, and back correction of the modeled slip reproduced well the former shoreline of Kisakata lagoon.
AB - The 10 July 1804 Kisakata earthquake occurred offshore Kisakata (Akita, Japan), and widespread felt shaking was reported from Matsumae (Hokkaido) to OhmiHachiman (Shiga Prefecture). The earthquake caused strong ground motions that extensively damaged areas near the epicenter, such as along the coast of Kisakata, and the resultant tsunami caused extensive damage along the coast from Kisakata to Sakata. Furthermore, Kisakata lagoon was uplifted by dislocation during the earthquake, exposing the lagoon floor. Here, we performed a field survey of the uplift distribution based on microtopographic remnants of the former shoreline of Kisakata lagoon and used historical documents to re-evaluate tsunami trace heights. Using ocean-bottom reflection profiles, we estimated a fault model for the earthquake and resultant tsunami. Our model indicates that an average of 5.6 m of slip on the fault (equivalent to an Mw 7.1 earthquake) is required to explain the observed crustal deformation and tsunami height distributions, and back correction of the modeled slip reproduced well the former shoreline of Kisakata lagoon.
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U2 - 10.1785/0220200074
DO - 10.1785/0220200074
M3 - Article
AN - SCOPUS:85096937978
SN - 0895-0695
VL - 91
SP - 2674
EP - 2684
JO - Seismological Research Letters
JF - Seismological Research Letters
IS - 5
ER -