气候变化领域集成服务门户(CCPortal): Seismo-Turbidites in Aysén Fjord (Southern Chile) Reveal a Complex Pattern of Rupture Modes Along the 1960 Megathrust Earthquake Segment

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DOI	10.1029/2020JB019405
	Seismo-Turbidites in Aysén Fjord (Southern Chile) Reveal a Complex Pattern of Rupture Modes Along the 1960 Megathrust Earthquake Segment
	Wils K.; Van Daele M.; Kissel C.; Moernaut J.; Schmidt S.; Siani G.; Lastras G.
发表日期	2020
ISSN	21699313
卷号	125 期号:9
英文摘要	Grainsize analysis and end-member modeling of a long sediment core from Aysén Fjord (southern Chile) allows to identify over 25 seismo-turbidites in the last 9,000 years. Considering the shaking intensities required to trigger these turbidites (V½-VI½), the majority can be related to megathrust earthquakes. Multiple studies in south-central Chile have aimed at finding traces of giant, tsunamigenic megathrust earthquakes leading to the current 5,500-year-long paleoseismological record of the Valdivia segment. However, none of these cover the southern third of the segment. Aysén Fjord allows to fill this data gap and presents the first, crucial paleoseismic data to demonstrate that the 1960 event was not unique for the Valdivia segment, yielding a recurrence rate of 321 ± 116 years in the last two millennia. Moreover, the oldest identified events in Aysén Fjord date back to 9,000 cal years BP and, thus, also extend the regional paleoseismological record in time. We infer a large temporal variability in rupture modes, with successions of full-segment ruptures alternating with partial and cascading ruptures. The latter seems to significantly postpone the occurrence of another full rupture when consecutively occurring in different parts of the segment. Additionally, one outstanding period of seismic quiescence—during which no megathrust earthquake evidence has been found at any paleoseismic site—occurred after a full rupture in AD ~745 that presents an unusual uplift/subsidence pattern. Such variability makes it highly speculative to anticipate the rupture mode of the next megathrust earthquake along the Valdivia segment. © 2020. American Geophysical Union. All Rights Reserved.
英文关键词	megathrust earthquakes; south-central Chile; turbidite paleoseismology; Valdivia segment; variable rupture mode
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/187646
作者单位	Renard Centre of Marine Geology (RCMG), Department of Geology, Ghent University, Ghent, Belgium; Laboratoire des Sciences du Climat et de l’Environnement/IPSL, CEA/CNRS/UVSQ, Université Paris-Saclay, Gif-sur-Yvette, France; Institute of Geology, University of Innsbruck, Innsbruck, Austria; EPOC, UMR CNRS 5805, Université de Bordeaux, Pessac, France; GEOPS, UMR 8148 Université de Paris, Orsay, France; GRC Geociències Marines, Universitat de Barcelona, Barcelona, Spain
推荐引用方式 GB/T 7714	Wils K.,Van Daele M.,Kissel C.,et al. Seismo-Turbidites in Aysén Fjord (Southern Chile) Reveal a Complex Pattern of Rupture Modes Along the 1960 Megathrust Earthquake Segment[J],2020,125(9).
APA	Wils K..,Van Daele M..,Kissel C..,Moernaut J..,Schmidt S..,...&Lastras G..(2020).Seismo-Turbidites in Aysén Fjord (Southern Chile) Reveal a Complex Pattern of Rupture Modes Along the 1960 Megathrust Earthquake Segment.Journal of Geophysical Research: Solid Earth,125(9).
MLA	Wils K.,et al."Seismo-Turbidites in Aysén Fjord (Southern Chile) Reveal a Complex Pattern of Rupture Modes Along the 1960 Megathrust Earthquake Segment".Journal of Geophysical Research: Solid Earth 125.9(2020).