Séminaire ISTerre

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Determination of earthquake hypocentral depth at regional and teleseismic distance: methods and uncertainties

vendredi 24 septembre 2021 - 10h30

Marine Laporte - CEA/DAM
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Seismicity catalogs are obtained using different location techniques and seismic networks, at different scales (dense temporary networks, permanent regional networks, teleseismic data). Earthquake hypocentre depths of such catalogs is associated to random uncertainties and systematic bias, due to uncertainties in velocity models or identification of seismic phase arrivals. Such bias particularly affect depth estimations and can lead to misinterpretation of the spatial distribution of seismicity. Such uncertainties are illustrated by studying the microseismicity in western Nepal using regional and temporary seismic networks. Estimated hypocentral depths are compared to estimations obtained from global networks using new techniques. The various observation scales can be combined using datasets of events with M>5 to evidence new sources of erros and enhance seismotectonic interpretations relying on a good estimation of hypocentral depth.

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Equipe organisatrice : Géophysique des Risques et de l’Environnement

Salle Dolomieu, Maison des Géosciences, 38400 Saint Martin d'Hères