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Bayesian inference on the initiation phase of the 2014 Iquique, Chile, earthquake / Cédric Twardzik in Earth and planetary science letters, vol 600 (15 December 2022)  

Public [article]  inEarth and planetary science letters > vol 600 (15 December 2022) . - n° 117835 Titre : Bayesian inference on the initiation phase of the 2014 Iquique, Chile, earthquake Type de document : Article/Communication Auteurs : Cédric Twardzik, Auteur ; Zacharie Duputel, Auteur ; Romain Jolivet, Auteur ; Emilie Klein, Auteur ; Paul Rebischung , Auteur Année de publication : 2022 Projets : SLES-S5 / Nocquet, Jean-Mathieu Article en page(s) : n° 117835 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale [Termes IGN] Chili [Termes IGN] coordonnées GNSS [Termes IGN] effondrement de terrain [Termes IGN] inférence [Termes IGN] matrice de covariance [Termes IGN] séisme [Termes IGN] série temporelle [Termes IGN] sismologie Résumé : (auteur) We investigate the initiation phase of the 2014 Mw8.1 Iquique earthquake in northern Chile. In particular, we focus on the month preceding the mainshock, a time period known to exhibit an intensification of the seismic and aseismic activity in the region. The goal is to estimate the time-evolution and partitioning of seismic and aseismic slip during the preparatory phase of the mainshock. To do so, we develop a Bayesian inversion scheme to infer the spatio-temporal evolution of pre-slip from position time-series along with the corresponding uncertainty. To extract the aseismic component to the pre-seismic motion, we correct geodetic observations from the displacement induced by foreshocks. We find that aseismic slip accounts for ∼80 percents of the slip budget. That aseismic slip takes the form of a slow-slip events occurring between 20 to 5 days before the future mainshock. This time-evolution is not consistent with self-accelerating fault slip, a model that is often invoked to explain earthquake nucleation. Instead, the slow-slip event seems to have interacted with the foreshock sequence such that the foreshocks contributed to the arrest of aseismic slip. In addition, we observe some evidence of late self-accelerating slip, but associated with large uncertainties, making it difficult to assess its reliability from our observations alone. Numéro de notice : A2022-698 Affiliation des auteurs : UMR IPGP-Géod+Ext (2020- ) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.epsl.2022.117835 Date de publication en ligne : 26/10/2022 En ligne : https://doi.org/10.1016/j.epsl.2022.117835 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=102117 [article]