Large Active Faults and the Wharton Basin Intraplate Earthquakes in the Eastern Indian Ocean

Chen Jie1; Guo Laiyin2; Yang Xiaodong3,4,5; Zhang Jinchang3,4,5; Zhang Zhiwen4,6; Sun Mengyu4,6; Lin Jingxue4,6

2022-11-01

10.1007/s11802-023-5518-4

Journal of Ocean University of China   Impact Factor & Quartile

1672-5182

1993-5021

In recent years, great earthquakes occurred within the Wharton Basin in the eastern Indian Ocean, and they have been associated with active faulting on the ancient oceanic crust. Large seismogenic faults were thought to be the fault reactivation on the ancient oceanic crust, but these phenomena are still unclear and require examination. This study used high-quality multibeam bathymetry and multichannel seismic data collected over the northern Ninetyeast Ridge to investigate detailed fault geometry, structure, and activity. We recognized 12 large linear active faults by integrating bathymetry maps and multichannel seismic reflection profiles. Our results showed that these faults have high angles, and they all displaced the basement and propagated to the seafloor with distinct fault scarps. They trended NWW-SEE with a spacing of 10-40 km and were parallel to each other and the nearby subfault of the 2012 great intraplate earthquake, suggesting similar stress fields. These faults are also in agreement with the orientations of magnetic isochrons, implying their formation by seafloor spreading. Furthermore, regarding the strike-slip focal mechanism of 2012 earthquakes, we proposed that these faults were created early by a normal spreading process and then evolved into a strike-slip pattern since the ancient oceanic crust approached the subduction zones.

Ninetyeast Ridge Wharton Basin strike-slip faults great earthquakes seismogenic structure earthquake mechanism

SCI

English

Others

Guangdong Basic and Applied Basic Research Foundation[2021B1515020098] ; Science and Technology Department of Guangxi Zhuang Autonomous Region[2019AC17008] ; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou)[GML2019ZD0205] ; National Natural Science Foundation of China[41890813] ; Chinese Academy of Sciences["133244KYSB20180029","131551KYSB20200021","Y4SL021001","QYZDY-SSW-DQC005","ISEE2021PY03","E1SL3C02"] ; South China Sea Institute of Oceanology of the Chinese Academy of Sciences[202207] ; Guangdong Provincial Research and Development Program in Key Areas[2020B1111520001]

Oceanography

Oceanography

WOS:000888707900001

OCEAN UNIV CHINA

Web of Science

1.Minist Nat Resources, Inst Oceanog 4, Beihai 536007, Peoples R China
2.Southern Univ Sci & Technol, Dept Ocean Sci & Engn, Shenzhen 518055, Peoples R China
3.Southern Marine Sci & Engn Guangdong Lab Guangzho, Guangzhou 511458, Peoples R China
4.Chinese Acad Sci, Innovat Acad South China Sea Ecol & Environm Engn, South China Sea Inst Oceanol, CAS Key Lab Ocean & Marginal Sea Geol, Guangzhou 511458, Peoples R China
5.CAS HEC, China Pakistan Joint Res Ctr Earth Sci, Islamabad 45320, Pakistan
6.Univ Chinese Acad Sci, Beijing 100049, Peoples R China

Chen Jie,Guo Laiyin,Yang Xiaodong,et al. Large Active Faults and the Wharton Basin Intraplate Earthquakes in the Eastern Indian Ocean[J]. Journal of Ocean University of China,2022.

Chen Jie.,Guo Laiyin.,Yang Xiaodong.,Zhang Jinchang.,Zhang Zhiwen.,...&Lin Jingxue.(2022).Large Active Faults and the Wharton Basin Intraplate Earthquakes in the Eastern Indian Ocean.Journal of Ocean University of China.

Chen Jie,et al."Large Active Faults and the Wharton Basin Intraplate Earthquakes in the Eastern Indian Ocean".Journal of Ocean University of China (2022).