An Integrated Study of Age and Formation of the Aru Trough, Eastern Banda Arc, Indonesia: Implications for Seismic Hazards

Zhang, Zhiwen1,2,3; Yang, Xiaodong1,4; Mooney, Walter D.5; Bell, Rebecca E.2; Zhao, Siyuan6; Lin, Jian1,4,7,8; Zheng, Tingting1,4; Xu, Haobo1,3

2024-09-01

10.1029/2024TC008449

TECTONICS   影响因子和分区

0278-7407

1944-9194

The Banda Arc in eastern Indonesia has a complex tectonic history involving oceanic and continental subduction, arc-continent collision and slab rollback. Among these the subduction rollback that began at 16 Ma shaped the regional tectonic configuration, causing notable upper plate extension evidenced by the Banda Sea and Weber Deep. However, the effects of subduction rollback on the lower plate remain less understood. The Aru Trough, part of subducting Australian continental margin, shows strong deformation and high seismicity, making it ideal for studying these effects. Utilizing multibeam bathymetry, seismic reflection profiles, GPS observations, seismicity and focal mechanisms, we investigate the crustal deformation, driving mechanisms and seismic risks in the Aru Trough under the background of Banda slab rollback. The Aru Trough shaped like an inverted triangle narrows from 160 to 40 km southward. It has a fast 53.8 mm/yr extensional rate at present, when combined with its maximum width suggesting a 3 Ma age. High-angle faults (>60 degrees) are present at its margins and interior. The trough has a high density of seismicity up to 5.9 events per 25 km(2), with dominant normal and strike-slip events, consistent with observed deformational patterns. The low seismic b-value of 0.82 +/- 0.01 suggests a high-stress state with potential for strong earthquakes (M-w >= 6.5). Our findings indicate that lower plate deformation is profoundly influenced by subduction rollback, oblique arc-continent collision and regional strike-slip faulting. Understanding deformation in the Aru Trough is crucial for grasping the broader tectonic evolution of the Banda Arc and assessing seismic risks.

Banda Arc subduction rollback Aru Trough extensional tectonics normal faults seismicity and risks

SCI

英语

其他

National Natural Science Foundation of China[42276222] ; National Science Foundation of China["SCSIO202207","SCSIO2024QY02"] ; Development Fund of South China Sea Institute of Oceanology of the Chinese Academy of Sciences["131551KYSB20200021","Y4SL021"] ; Chinese Academy of Sciences[202304910314] ; China Scholarship Council program[2023A04J0189] ; Guangzhou Science and Technology Plan Project[G20230607009E]

Geochemistry & Geophysics

Geochemistry & Geophysics

WOS:001317531100001

AMER GEOPHYSICAL UNION

Web of Science

1.Chinese Acad Sci, CAS Key Lab Ocean & Marginal Sea Geol, Guangzhou, Peoples R China
2.Imperial Coll London, Dept Earth Sci & Engn, London, England
3.Univ Chinese Acad Sci, Beijing, Peoples R China
4.CAS HEC, China Pakistan Joint Res Ctr Earth Sci, Islamabad, Pakistan
5.US Geol Survey, Earthquake Sci Ctr, Menlo Pk, CA USA
6.Australian Natl Univ, Res Sch Earth Sci, Canberra, ACT, Australia
7.Southern Univ Sci & Technol, Adv Inst Ocean Res, Shenzhen, Peoples R China
8.Southern Univ Sci & Technol, Dept Ocean Sci & Engn, Shenzhen, Peoples R China

Zhang, Zhiwen,Yang, Xiaodong,Mooney, Walter D.,et al. An Integrated Study of Age and Formation of the Aru Trough, Eastern Banda Arc, Indonesia: Implications for Seismic Hazards[J]. TECTONICS,2024,43(9).

Zhang, Zhiwen.,Yang, Xiaodong.,Mooney, Walter D..,Bell, Rebecca E..,Zhao, Siyuan.,...&Xu, Haobo.(2024).An Integrated Study of Age and Formation of the Aru Trough, Eastern Banda Arc, Indonesia: Implications for Seismic Hazards.TECTONICS,43(9).

Zhang, Zhiwen,et al."An Integrated Study of Age and Formation of the Aru Trough, Eastern Banda Arc, Indonesia: Implications for Seismic Hazards".TECTONICS 43.9(2024).