气候变化领域集成服务门户(CCPortal): Near Trench 3D Seismic Attenuation Offshore Northern Hikurangi Subduction Margin, North Island, New Zealand

CCPortal

DOI	10.1029/2020JB020810
	Near Trench 3D Seismic Attenuation Offshore Northern Hikurangi Subduction Margin, North Island, New Zealand
	Nakai J.S.; Sheehan A.F.; Abercrombie R.E.; Eberhart-Phillips D.
发表日期	2021
ISSN	21699313
卷号	126 期号:3
英文摘要	We image seismic attenuation near the Hikurangi trench offshore New Zealand, using ocean bottom and land-based seismometers, revealing high attenuation above a recurring shallow slow-slip event and within the subducting Hikurangi Plateau. The Hikurangi subduction margin east of the North Island, New Zealand is the site of frequent shallow slow slip events. Overpressured fluids are hypothesized to lead to slow slip at shallow depths close to the oceanic trench. Seismic attenuation, energy loss of seismic waves, can be used to detect high temperatures, melt, the presence of fluids, and fractures. We use local earthquake P- and S-waves from 180 earthquakes to invert for t*, and subsequently invert for Qp and Qs, offshore the North Island directly above the area of slow slip. We image Qp and Qs to ∼25 km depth, increasing resolution of previously identified coastal low Q (100–300), and finding a new region of even higher attenuation (Qp and Qs < 50–100) directly above the shallow slow slip event of 2014–2015, beneath the offshore seismic array. This highest attenuation is downdip of a subducting seamount, and is spatially correlated with a high seismic reflectivity zone and Vp/Vs > 1.85, all of which provide evidence for the presence of fluids. The Qp and Qs is low at the trench (<50–100) and in the subducting plate (100–200), suggesting that seismic wave scattering due to faults, fractures, and the inherent heterogeneous composition of the Hikurangi Plateau, a large igneous province, plays a role in seismic attenuation. © 2021. American Geophysical Union. All Rights Reserved.
英文关键词	fluids; seismic attenuation; subduction zone
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/187303
作者单位	Department of Earth and Planetary Sciences, University of New Mexico, Albuquerque, NM, United States; Department of Geological Sciences, Cooperative Institute for Research in the Environmental Sciences, University of Colorado Boulder, Boulder, CO, United States; Department of Earth and Environment, Boston University, Boston, MA, United States; GNS Science, Lower Hutt, New Zealand
推荐引用方式 GB/T 7714	Nakai J.S.,Sheehan A.F.,Abercrombie R.E.,et al. Near Trench 3D Seismic Attenuation Offshore Northern Hikurangi Subduction Margin, North Island, New Zealand[J],2021,126(3).
APA	Nakai J.S.,Sheehan A.F.,Abercrombie R.E.,&Eberhart-Phillips D..(2021).Near Trench 3D Seismic Attenuation Offshore Northern Hikurangi Subduction Margin, North Island, New Zealand.Journal of Geophysical Research: Solid Earth,126(3).
MLA	Nakai J.S.,et al."Near Trench 3D Seismic Attenuation Offshore Northern Hikurangi Subduction Margin, North Island, New Zealand".Journal of Geophysical Research: Solid Earth 126.3(2021).