Deep Seismic Structure Across the Southernmost Mariana Trench: Implications for Arc Rifting and Plate Hydration

doi:10.1029/2018JB017080

CORC > 南海海洋研究所 > 中国科学院南海海洋研究所 > 中科院边缘海地质重点实验室

	Deep Seismic Structure Across the Southernmost Mariana Trench: Implications for Arc Rifting and Plate Hydration
	Wan, Kuiyuan ; Lin, Jian 2; Xia, Shaohong ; Sun, Jinlong ; Xu, Min ; Yang, Hongfeng 1; Zhou, Zhiyuan ; Zeng, Xin ; Cao, Jinghe ; Xu, Huilong
刊名	JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
	2019
卷号	124 期号:5 页码:4710
关键词	arc rifting plate hydration southernmost Mariana Trench seismic tomography
ISSN号	2169-9313
DOI	10.1029/2018JB017080
英文摘要	The southernmost Mariana margin lacks a mature island arc and thus differs significantly from the central-north Mariana and Izu-Bonin margins. This paper presents a new P wave velocity model of the crust and uppermost mantle structure based on a 349-km-long profile of wide-angle reflection/refraction data. The active source seismic experiment was conducted from the subducting Pacific plate to the overriding Philippine plate, passing through the Challenger Deep. The subducting plate has an average crustal thickness of similar to 6.0 km with Vp of 7.0 +/- 0.2 km/s at the base of the crust and low values of only 5.5-6.9 km/s near the trench axis. The uppermost mantle of the subducting plate is characterized by low velocities of 7.0-7.3 km/s. The overriding plate has a maximum crustal thickness of similar to 18 km beneath the forearc with Vp of similar to 7.4 km/s at the crustal bottom and 7.5-7.8 km/s in the uppermost mantle. A zone of slight velocity reduction is imaged beneath the Southwest Mariana Rift that is undergoing active rifting. The observed significant velocity reduction in a near-trench crustal zone of similar to 20-30 km in the subducting plate is interpreted as a result of faulting-induced porosity changes and fracture-filling fluids. The velocity reduction in the uppermost mantle of both subducting and overriding plates is interpreted as mantle serpentinization with fluid sources from dehydration of the subducting plate and/or fluid penetration along faults. Plain Language Summary The southernmost Mariana margin is a convergence margin that lacks a mature island arc. The trench reaches the deepest point on Earth at the Challenger Deep, the origin of which is still little known. We acquired and analyzed new active source wide-angle reflection/refraction seismic data along a profile across the Challenge Deep, obtaining a new model of crustal and uppermost mantle velocity structure of both the subducting Pacific and overriding Philippine Sea plates. Significant velocity reduction is observed in the crust of the subducting plate, especially in a 20- to 30-km-wide zone near the trench axis, which is interpreted as a result of faulting-induced porosity changes and fracture-filling fluids. A zone of slight velocity reduction is imaged beneath the tectonically active Southwest Mariana Rift. Significant velocity reduction is also observed in the uppermost mantle of both subducting and overriding plates and is interpreted as a result of mantle serpentinization.
内容类型	期刊论文
源URL	[http://ir.scsio.ac.cn/handle/344004/17959]
专题	南海海洋研究所_中科院边缘海地质重点实验室
作者单位	1.Woods Hole Oceanog Inst, Dept Geol & Geophys, Woods Hole, MA 02543 USA 2.Chinese Acad Sci, South China Sea Inst Oceanol, Key Lab Ocean & Marginal Sea Geol, Guangzhou, Guangdong, Peoples R China 3.Chinese Univ Hong Kong, Fac Sci, Earth Syst Sci Programme, Shatin, Hong Kong, Peoples R China
推荐引用方式 GB/T 7714	Wan, Kuiyuan,Lin, Jian,Xia, Shaohong,et al. Deep Seismic Structure Across the Southernmost Mariana Trench: Implications for Arc Rifting and Plate Hydration[J]. JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH,2019,124(5):4710, 4727.
APA	Wan, Kuiyuan.,Lin, Jian.,Xia, Shaohong.,Sun, Jinlong.,Xu, Min.,...&Xu, Huilong.(2019).Deep Seismic Structure Across the Southernmost Mariana Trench: Implications for Arc Rifting and Plate Hydration.JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH,124(5),4710.
MLA	Wan, Kuiyuan,et al."Deep Seismic Structure Across the Southernmost Mariana Trench: Implications for Arc Rifting and Plate Hydration".JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH 124.5(2019):4710.