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DOI | 10.1016/j.epsl.2021.116887 |
Seismicity and velocity structure in the vicinity of repeating slow slip earthquakes, northern Hikurangi subduction zone, New Zealand | |
Mochizuki K.; Henrys S.; Haijima D.; Warren-Smith E.; Fry B. | |
发表日期 | 2021 |
ISSN | 0012821X |
卷号 | 563 |
英文摘要 | Using an 11-month (April 2012 to March 2013) deployment of Ocean Bottom Seismographs along the northern Hikurangi subduction zone, New Zealand, we located 2005 earthquakes (M 0.7-4.5) and obtained detailed 3-D Vp and Vs models for a region where a spectrum of subduction fault slip behavior is observed. Our analysis over a 120 × 110 km2 onshore-offshore area reveals high Vp/Vs (>1.8) in the subducting 10 km thick Hikurangi Plateau oceanic crust below an area of repeating slow slip events (SSEs), that are assumed to occur on the plate megathrust. Low Vp/Vs is mapped in a 15 km wide domain along the coastline, offshore Gisborne, marked by low Qs/Qp. Seismicity is absent from the core of high Vp/Vs anomalies (∼2.0) and within the band with lower Vp/Vs, but earthquakes are distributed vertically and are widespread in adjacent high Vp/Vs (∼1.85-1.95) regions along the trend of the coastline. Down-dip and along-strike variation of the Vp/Vs structure of the subducting Hikurangi Plateau could be the result of dehydration process caused by reactivated bending-related faults. Zones of vertical extensional fault–fracture in the subducting crust may act as conduits for the discharge of overpressured fluid and episodic hydrofracturing. During our deployment a large SSE (Mw6.8) occurred in February 2013. In response, seismicity became active in central Hawke Bay and at the down-dip edge of a previously mapped high-amplitude reflectivity zone. Microseismicity appeared synchronous with the slip propagation of the SSEs and may have been initiated by the slip. Our results hold implications for understanding of the physical environments conducive to slow slip generation and represent an important baseline for future seismicity work in the region. © 2021 The Author(s) |
关键词 | bending-related faultsdehydration processfluid distributionseismic velocity structureseismicity gapsubduction zone seismicity |
英文关键词 | Earthquakes; Fault slips; Landforms; Offshore oil well production; Seismic waves; Bending-related fault; Dehydration process; Fluid distribution; New zealand; Seismic velocity structure; Seismicity gap; Slow slip events; Subduction zone seismicities; Subduction zones; Velocity structure; Dehydration; earthquake event; earthquake magnitude; normal fault; oceanic crust; seismic velocity; seismicity; strike-slip fault; subduction zone; velocity structure; New Zealand |
语种 | 英语 |
来源期刊 | Earth and Planetary Science Letters |
文献类型 | 期刊论文 |
条目标识符 | http://gcip.llas.ac.cn/handle/2XKMVOVA/203225 |
作者单位 | Earthquake Research Institute, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-0032, Japan; GNS Science, 1 Fairway Drive, Avalon 5010 PO Box 30-368, Lower Hutt, 5040, New Zealand; JX Nippon Oil & Gas Exploration Corporation, 1-1-2 Otemachi, Chiyoda-ku, Tokyo, 100-8163, Japan |
推荐引用方式 GB/T 7714 | Mochizuki K.,Henrys S.,Haijima D.,et al. Seismicity and velocity structure in the vicinity of repeating slow slip earthquakes, northern Hikurangi subduction zone, New Zealand[J],2021,563. |
APA | Mochizuki K.,Henrys S.,Haijima D.,Warren-Smith E.,&Fry B..(2021).Seismicity and velocity structure in the vicinity of repeating slow slip earthquakes, northern Hikurangi subduction zone, New Zealand.Earth and Planetary Science Letters,563. |
MLA | Mochizuki K.,et al."Seismicity and velocity structure in the vicinity of repeating slow slip earthquakes, northern Hikurangi subduction zone, New Zealand".Earth and Planetary Science Letters 563(2021). |
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