气候变化领域集成服务门户(CCPortal): Methoni Mw 6.8 rupture and aftershocks distribution from a dense array of OBS and land seismometers, offshore SW Hellenic subduction

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DOI	10.1016/j.tecto.2020.228643
	Methoni Mw 6.8 rupture and aftershocks distribution from a dense array of OBS and land seismometers, offshore SW Hellenic subduction
	Sachpazi M.; Kapetanidis V.; Charalampakis M.; Laigle M.; Kissling E.; Fokaefs A.; Daskalaki E.; Flueh E.; Hirn A.
发表日期	2020
ISSN	00401951
卷号	796
英文摘要	Along the south-western offshore Hellenic subduction zone, the overriding Aegean upper plate above the Mediterranean oceanic lithosphere generates uncommon large earthquakes on the offshore megathrust fault. The largest subduction thrust event, for half a century, has been the 14 February 2008 Methoni earthquake (Mw = 6.8) that occurred offshore of the southwest coast of Peloponnesus. We conducted micro-seismicity experiments around the rupture area and forearc domain -between Peloponnesus and Crete- using ocean bottom seismometers (OBS) jointly with land-based seismological stations. Our first experiment in 2006, had revealed an association of the Matapan Trough, a 400-km-long forearc basin, with local seismicity clustering and a possible gap in activity over the later Methoni rupture area. Here we present new data of post-Methoni seismic activity, recorded during a time-span of 11 months, beginning in October 2008 within the period of proposed afterslip on the megathrust, by an extended and dense seismic array consisting of up to 33 OBS. A minimum 1D velocity model was constructed for the region to provide better constraints on absolute locations and double-difference relocation was applied to produce an enhanced image of the spatial distribution of hypocenters. The high resolution earthquake locations confirm correlation of the Matapan Trough with local seismicity as a regional feature, also filling up the previously observed gap. Over the Methoni rupture area, we constrain seismicity to be located mainly within the upper plate. Hypocenters are also resolved above the updip and downdip edges of the rupture area, respectively. Seismic activity provides hints of upper plate structures which were activated in response to post-seismic deformation spreading within the forearc crust. Our findings highlight the characteristics of a megathrust domain which is related with a highly deformable overriding plate and controlled by a segmented lower plate topography. © 2020 Elsevier B.V.
关键词	Aftershocks Afterslip Methoni earthquake SW Hellenic subduction Upper plate deformation
英文关键词	Deformation; Image enhancement; Offshore oil well production; Plates (structural components); Seismographs; Topography; Double differences; Earthquake location; Hellenic subduction zone; Large earthquakes; Minimum 1-d velocity models; Ocean bottom seismometer; Oceanic lithosphere; Seismic deformation; Earthquakes; aftershock; deformation; earthquake hypocenter; earthquake rupture; forearc basin; ocean bottom seismometer; seismicity; slip rate; subduction zone
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/207869
作者单位	Institute of Geodynamics, National Observatory of Athens, Athens, Greece; Department of Geophysics-Geothermics, Faculty of Geology and Geoenvironment, National and Kapodistrian University of Athens, Athens, Greece; Université Nice Sophia Antipolis, CNRS, IRD, Observatoire de la Côte d'Azur, Géoazur, Valbonne, France; Institute of Geophysics, ETH, Zürich, Zurich, Switzerland; GEOMAR Helmholtz Centre for Ocean Research, Kiel, Germany; Institut de Physique du Globe de Paris, Sorbonne Paris Cité, Paris VII – Denis Diderot University, Paris, France
推荐引用方式 GB/T 7714	Sachpazi M.,Kapetanidis V.,Charalampakis M.,et al. Methoni Mw 6.8 rupture and aftershocks distribution from a dense array of OBS and land seismometers, offshore SW Hellenic subduction[J],2020,796.
APA	Sachpazi M..,Kapetanidis V..,Charalampakis M..,Laigle M..,Kissling E..,...&Hirn A..(2020).Methoni Mw 6.8 rupture and aftershocks distribution from a dense array of OBS and land seismometers, offshore SW Hellenic subduction.Tectonophysics,796.
MLA	Sachpazi M.,et al."Methoni Mw 6.8 rupture and aftershocks distribution from a dense array of OBS and land seismometers, offshore SW Hellenic subduction".Tectonophysics 796(2020).