气候变化领域集成服务门户(CCPortal): Seismicity in the upper plate of the Northern Chilean offshore forearc: Evidence of splay fault south of the Mejillones Peninsula

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DOI	10.1016/j.tecto.2020.228706
	Seismicity in the upper plate of the Northern Chilean offshore forearc: Evidence of splay fault south of the Mejillones Peninsula
	Pastén-Araya F.; Potin B.; Ruiz S.; Zerbst L.; Aden-Antoniów F.; Azúa K.; Rivera E.; Rietbrock A.; Salazar P.; Fuenzalida A.
发表日期	2021
ISSN	00401951
卷号	800
英文摘要	The region around the Mejillones Peninsula is characterized by major onshore and offshore fault systems. The existence of major splay faults in these fault systems has been debated. To improve our undestanding of seismotectonic processes affecting the MP, we built a new catalog of aftershocks of the 1995 Antofagasta earthquake (Mw 8.1) recorded by the CINCA seismic network. In addition, we build a three-dimensional tomographic model to determine the physical properties of the upper plate using arrival times from our new catalog combined with other earthquakes catalogs derived from several networks deployments across the MP. We detected seismicity in the outer wedge of the upper plate. The seismicity is partially defined by a clear lineament between 22 and 5 km depth that we defined as a splay fault. The focal mechanisms indicate a rupture plane with NE orientation and SE dip. The seismicity in the upper plate and splay fault are located in the areas in which the Vp and Vs velocities are decreased and the Vp/Vs ratio is increased, suggesting a fractured fault zone within the outer wedge of the upper plate. We propose the presence of fluids in the fracture fault zone within the outer wedge because the decrease in Vs larger than that of Vp and repeating earthquakes clusters were detected. Our observations present clear evidence of the activation of the splay fault in the outer wedge of the North Chilean offshore forearc. © 2020 Elsevier B.V.
关键词	3D Tomography Model Aftershocks North of Chile Offshore Forearc Splay Fault
英文关键词	Faulting; Offshore oil well production; Structural geology; Arrival time; Fault system; Focal mechanism; Offshore fault system; Repeating earthquake; Rupture plane; Seismic networks; Seismotectonics; Earthquakes; aftershock; basin evolution; earthquake event; earthquake magnitude; fault zone; plate motion; seismicity; three-dimensional modeling; Chile
语种	英语
来源期刊	Tectonophysics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/208050
作者单位	Departamento de Geofísica, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile; Geophysical Institute (GPI), Karlsruhe Institute of Technology, Karlsruhe, Germany; Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, United States; European-Mediterranean Seismological Centre, c/o CEA, Arpajon, Cedex, 91297, France; Departamento de Ciencias Geológicas, Universidad Católica del Norte, Centro de Investigación para la Gestión Integrada del Riesgo de Desastre (CIGIDEN), Antofagasta, Chile
推荐引用方式 GB/T 7714	Pastén-Araya F.,Potin B.,Ruiz S.,et al. Seismicity in the upper plate of the Northern Chilean offshore forearc: Evidence of splay fault south of the Mejillones Peninsula[J],2021,800.
APA	Pastén-Araya F..,Potin B..,Ruiz S..,Zerbst L..,Aden-Antoniów F..,...&Fuenzalida A..(2021).Seismicity in the upper plate of the Northern Chilean offshore forearc: Evidence of splay fault south of the Mejillones Peninsula.Tectonophysics,800.
MLA	Pastén-Araya F.,et al."Seismicity in the upper plate of the Northern Chilean offshore forearc: Evidence of splay fault south of the Mejillones Peninsula".Tectonophysics 800(2021).