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Shallow geological structures triggered during the Mw 6.4 Meinong earthquake, southwestern Taiwan / Maryline Le Béon in Terrestrial Atmospheric Oceanic sciences journal, vol 28 n° 5 (October 2017)  

Public [article]  inTerrestrial Atmospheric Oceanic sciences journal > vol 28 n° 5 (October 2017) . - pp 663 - 681 Titre : Shallow geological structures triggered during the Mw 6.4 Meinong earthquake, southwestern Taiwan Type de document : Article/Communication Auteurs : Maryline Le Béon, Auteur ; Mong-Han Huang, Auteur ; John Suppe, Auteur ; Shiuh-Tsann Huang, Auteur ; Erwan Pathier, Auteur ; Wen-Jeng Huang, Auteur ; Chien-Liang Chen, Auteur ; Bénédicte Fruneau , Auteur ; Stéphane Baize, Auteur ; Kuo-En Ching, Auteur ; Jyr-Ching Hu, Auteur Année de publication : 2017 Projets : TOSCA / Article en page(s) : pp 663 - 681 Note générale : bibliographie TOSCA project Tersol Glob-Taiwan Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications [Termes IGN] déformation de la croute terrestre [Termes IGN] données GPS [Termes IGN] faille géologique [Termes IGN] image radar moirée [Termes IGN] interféromètrie par radar à antenne synthétique [Termes IGN] séisme [Termes IGN] Taïwan Résumé : (auteur) The Meinong earthquake generated up to ~10 cm surface displacement located 10 - 35 km west of the epicenter and monitored by InSAR and GPS. In addition to coseismic deformation related to the deep earthquake source, InSAR revealed three sharp surface displacement gradients. One of them is extensional and is inconsistent with the westward interseismic shortening of ~45 mm yr-1 in this region. The gradient sharpness suggests slip triggering on shallow structures, some of which were not well documented before. To characterize these shallow structures, we investigated potential surface ruptures in the field. Sets of ~NS tension cracks distributed over 25 - 300 m width, with cumulative extension in the same order as InSAR observations, were found along 5.5 km distance along the extensional gradient and are interpreted as surface rupture. We build two E-W regional balanced cross-sections, based on surface geology, subsurface data, and coseismic and interseismic geodetic data. From the Coastal Plain to the east edge of the coseismic deformation area, we propose a series of three active west-dipping backthrusts: the Houchiali fault, the Napalin-Pitou backthrust, and the Lungchuan backthrust. They all root on the 3.5 - 4.0 km deep Tainan detachment located near the base of the 3-km-thick Gutingkeng mudstone. Further east, the detachment would ramp down to ~7 km depth. Coseismic surface deformation measurements suggest that, in addition to the deeper (15 - 20 km) main rupture plane, mostly the ramp, the Lungchuan backthrust, and the Tainan detachment were activated during or right after the earthquake. Local extension is considered as transient deformation at the west edge of the shallow main slip zone. Numéro de notice : A2017-888 Affiliation des auteurs : UPEM-LASTIG+Ext (2016-2019) Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.3319/TAO.2017.03.20.02 En ligne : https://doi.org/10.3319/TAO.2017.03.20.02 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=91876 [article]