气候变化领域集成服务门户(CCPortal): Seismic Velocity Heterogeneity of the Hikurangi Subduction Margin, New Zealand: Elevated Pore Pressures in a Region With Repeating Slow Slip Events

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DOI	10.1029/2020JB021605
	Seismic Velocity Heterogeneity of the Hikurangi Subduction Margin, New Zealand: Elevated Pore Pressures in a Region With Repeating Slow Slip Events
	Yarce J.; Sheehan A.; Roecker S.; Mochizuki K.
发表日期	2021
ISSN	21699313
卷号	126 期号:5
英文摘要	We investigated the seismic velocity structure of the Hikurangi margin in New Zealand to uncover the physical features of the subduction zone and explore the relationships between microearthquake seismicity, seismic velocity structure, and slow slip events. Using local earthquake tomography with data collected from both temporary ocean bottom seismometers and on-land permanent seismic stations, we used the tomography code TomoFD to iteratively perform a damped least squared inversion of absolute P and S arrival times to obtain relocated hypocenters and generate 3D velocity models for Vp and Vp/Vs. The seismic tomography images show two high Vp/Vs anomalies, one offshore and adjacent to a subducted seamount and the other beneath the North Island of New Zealand. The ∼50-km wide offshore anomaly extends ∼10 km beneath the plate interface and lies directly beneath the area that slipped at least 50 mm during the 2 week-long 2014 slow slip event. High Vp/Vs values may be related to high pore fluid pressures from subducted sediments, and such increases in pore fluid pressures have been suggested to trigger the occurrence of slow slip events in active subduction zones. The second onshore high Vp/Vs anomaly is located in the overlying plate and subducting slab and correlates with areas suggested by other geophysical techniques to be rich in fluids. Our seismic imaging supports interpretations that subduction processes in the Hikurangi margin are highly dependent on physical features such as subducted seamounts and fluid-rich sediments. © 2021. American Geophysical Union. All Rights Reserved.
英文关键词	fluids; Hikurangi margin; pore pressures; seismic tomography; slow slip events; Vp/Vs
语种	英语
来源期刊	Journal of Geophysical Research: Solid Earth
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/187167
作者单位	Cooperative Institute for Research in Environmental Sciences and Department of Geological Sciences, University of Colorado Boulder, Boulder, CO, United States; Now at Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI, United States; Rensselaer Polytechnic Institute, Troy, NY, United States; Earthquake Research Institute, University of Tokyo, Tokyo, Japan
推荐引用方式 GB/T 7714	Yarce J.,Sheehan A.,Roecker S.,et al. Seismic Velocity Heterogeneity of the Hikurangi Subduction Margin, New Zealand: Elevated Pore Pressures in a Region With Repeating Slow Slip Events[J],2021,126(5).
APA	Yarce J.,Sheehan A.,Roecker S.,&Mochizuki K..(2021).Seismic Velocity Heterogeneity of the Hikurangi Subduction Margin, New Zealand: Elevated Pore Pressures in a Region With Repeating Slow Slip Events.Journal of Geophysical Research: Solid Earth,126(5).
MLA	Yarce J.,et al."Seismic Velocity Heterogeneity of the Hikurangi Subduction Margin, New Zealand: Elevated Pore Pressures in a Region With Repeating Slow Slip Events".Journal of Geophysical Research: Solid Earth 126.5(2021).