DOI: 10.1016/j.epsl.2018.02.030
Scopus记录号: 2-s2.0-85042948029
论文题名: Does permanent extensional deformation in lower forearc slopes indicate shallow plate-boundary rupture?
作者: Geersen J. ; Ranero C.R. ; Kopp H. ; Behrmann J.H. ; Lange D. ; Klaucke I. ; Barrientos S. ; Diaz-Naveas J. ; Barckhausen U. ; Reichert C.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2018
卷: 489 起始页码: 17
结束页码: 27
语种: 英语
英文关键词: active tectonics
; marine forearc
; Northern Chile
; permanent deformation
; seismic gap
; subduction-zone
Scopus关键词: Deformation
; Fault slips
; Hazards
; Tsunamis
; Active tectonics
; Forearc
; Northern Chile
; Permanent deformations
; Seismic gaps
; Subduction zones
; Earthquakes
; active fault
; active margin
; deformation mechanism
; earthquake mechanism
; earthquake recurrence
; earthquake rupture
; extensional tectonics
; forearc basin
; marine environment
; plate boundary
; seismic hazard
; seismic source
; seismicity
; subduction zone
; tectonic setting
; Chile
英文摘要: Seismic rupture of the shallow plate-boundary can result in large tsunamis with tragic socio-economic consequences, as exemplified by the 2011 Tohoku-Oki earthquake. To better understand the processes involved in shallow earthquake rupture in seismic gaps (where megathrust earthquakes are expected), and investigate the tsunami hazard, it is important to assess whether the region experienced shallow earthquake rupture in the past. However, there are currently no established methods to elucidate whether a margin segment has repeatedly experienced shallow earthquake rupture, with the exception of mechanical studies on subducted fault-rocks. Here we combine new swath bathymetric data, unpublished seismic reflection images, and inter-seismic seismicity to evaluate if the pattern of permanent deformation in the marine forearc of the Northern Chile seismic gap allows inferences on past earthquake behavior. While the tectonic configuration of the middle and upper slope remains similar over hundreds of kilometers along the North Chilean margin, we document permanent extensional deformation of the lower slope localized to the region 20.8°S–22°S. Critical taper analyses, the comparison of permanent deformation to inter-seismic seismicity and plate-coupling models, as well as recent observations from other subduction-zones, including the area that ruptured during the 2011 Tohoku-Oki earthquake, suggest that the normal faults at the lower slope may have resulted from shallow, possibly near-trench breaking earthquake ruptures in the past. In the adjacent margin segments, the 1995 Antofagasta, 2007 Tocopilla, and 2014 Iquique earthquakes were limited to the middle and upper-slope and the terrestrial forearc, and so are upper-plate normal faults. Our findings suggest a seismo-tectonic segmentation of the North Chilean margin that seems to be stable over multiple earthquake cycles. If our interpretations are correct, they indicate a high tsunami hazard posed by the yet un-ruptured southern segment of the seismic gap. © 2018 The Authors Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/109968
Appears in Collections: 影响、适应和脆弱性 气候变化事实与影响
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作者单位: GEOMAR Helmholtz Centre for Ocean Research Kiel, Wischhofstrasse 1-3, Kiel, 24148, Germany; Barcelona Center for Subsurface Imaging, Instituto de Ciencias del Mar, CSIC, Passeig Maritim de la Barceloneta 37-49, Barcelona, 08003, Spain; ICREA, Pg. Lluís Companys 23, Barcelona, 08010, Spain; Centro Sismológico Nacional, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Blanco Encalada 2002, Santiago, Chile; Escuela de Ciencias del Mar, Pontificia Universidad Católica de Valparaíso, Av. Altamirano 1480, Valparaíso, Chile; Bundesanstalt für Geowissenschaften und Rohstoffe (BGR), Stilleweg 2, Hannover, 30655, Germany
Recommended Citation:
Geersen J.,Ranero C.R.,Kopp H.,et al. Does permanent extensional deformation in lower forearc slopes indicate shallow plate-boundary rupture?[J]. Earth and Planetary Science Letters,2018-01-01,489