TY - JOUR
T1 - Coulomb stress changes triggering surface pop-up during the 2016 Mw 6.4 Meinong earthquake with implications for earthquake-induced mud diapiring in SW Taiwan
AU - Mai, Hue Anh
AU - Lee, Jian Cheng
AU - Chen, Kate Huihsuan
AU - Wen, Kuo Liang
N1 - Funding Information:
We are grateful for many constructive comments and suggestions from Chung-Han Chan and an anonymous reviewer, which substantially helped to improve the manuscript. This research was supported by the Ministry of Science and Technology (MOST) of Taiwan (grants MOST 107-2116-M-001 -026 -MY3). This is also part of the PhD dissertation of the first author. A part of the scholarship for the first author is under the Taiwan International Graduate Program (TIGP) — Earth System Science Program, between Academia Sinica, Taiwan and National Central University, Taiwan . This is a contribution of Institute of Earth Sciences, Academia Sinica, IESAS-2393.
Funding Information:
We are grateful for many constructive comments and suggestions from Chung-Han Chan and an anonymous reviewer, which substantially helped to improve the manuscript. This research was supported by the Ministry of Science and Technology (MOST) of Taiwan (grants MOST 107-2116-M-001 -026 -MY3). This is also part of the PhD dissertation of the first author. A part of the scholarship for the first author is under the Taiwan International Graduate Program (TIGP) ? Earth System Science Program, between Academia Sinica, Taiwan and National Central University, Taiwan. This is a contribution of Institute of Earth Sciences, Academia Sinica, IESAS-2393.
Publisher Copyright:
© 2021 Elsevier Ltd
PY - 2021/9/15
Y1 - 2021/9/15
N2 - We investigated the 2016 Meinong earthquake (Mw 6.4) in southwestern Taiwan, which caused surface pop-up in an area of 10x15 km2 with maximum uplift of 12 cm, where lies an array of mud volcanoes and possible underlying mud diapir. We calculated 3D strain tensor in a 3D mesh with 5x5x2 km grids in the epicentral area induced by the Coulomb stress change due to coseismic fault slip. We obtained substantial contraction strain (10−5–10−6) that occurred in a lobe showing “squeezing” at the depth of 5–14 km below the surface pop-up area. Dilatation strain (10−5–10−6) occurred at shallow level (0–3 km) with a radial pattern around the surface pop-up area. Combining with local geology, which is composed of Mio-Pliocene ~5-km-thick mudstone in a fold-thrust belt, we interpret that the 2016 Meinong coseismic surface pop-up was closely related to mud diapirs/volcanoes, which were likely reactivated by sudden increase of fluid pore-pressure in the basal reservoir (at 5–6 km depth) and dilatation in the shallow level. We also explored the potential effects of the Coulomb stress transfer on nearby receiver faults – including three arrays of mud diapir, the regional decollement, a suspected backthrust and one thrust close to the pop-up area. Our results show that the Coulomb stress transfer a) favors NNE-trending mud diapirs in the coseismic pop-up area, with a combination of clamping stress changes at 5–6 km depth and unclamping stress changes at 0–4 km depth, and b) it does not favor triggered thrust slip on the regional thrusts.
AB - We investigated the 2016 Meinong earthquake (Mw 6.4) in southwestern Taiwan, which caused surface pop-up in an area of 10x15 km2 with maximum uplift of 12 cm, where lies an array of mud volcanoes and possible underlying mud diapir. We calculated 3D strain tensor in a 3D mesh with 5x5x2 km grids in the epicentral area induced by the Coulomb stress change due to coseismic fault slip. We obtained substantial contraction strain (10−5–10−6) that occurred in a lobe showing “squeezing” at the depth of 5–14 km below the surface pop-up area. Dilatation strain (10−5–10−6) occurred at shallow level (0–3 km) with a radial pattern around the surface pop-up area. Combining with local geology, which is composed of Mio-Pliocene ~5-km-thick mudstone in a fold-thrust belt, we interpret that the 2016 Meinong coseismic surface pop-up was closely related to mud diapirs/volcanoes, which were likely reactivated by sudden increase of fluid pore-pressure in the basal reservoir (at 5–6 km depth) and dilatation in the shallow level. We also explored the potential effects of the Coulomb stress transfer on nearby receiver faults – including three arrays of mud diapir, the regional decollement, a suspected backthrust and one thrust close to the pop-up area. Our results show that the Coulomb stress transfer a) favors NNE-trending mud diapirs in the coseismic pop-up area, with a combination of clamping stress changes at 5–6 km depth and unclamping stress changes at 0–4 km depth, and b) it does not favor triggered thrust slip on the regional thrusts.
KW - 2016 Meinong earthquake
KW - Coulomb stress changes
KW - Earthquake triggering
KW - Mud diapir
KW - Seismic hazard
KW - Taiwan
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U2 - 10.1016/j.jseaes.2021.104847
DO - 10.1016/j.jseaes.2021.104847
M3 - Article
AN - SCOPUS:85107781195
VL - 218
JO - Journal of Asian Earth Sciences
JF - Journal of Asian Earth Sciences
SN - 1367-9120
M1 - 104847
ER -