New Seismotectonic Models of Metropolitan France and Neighboring Intraplate Regions for Seismic Hazard Assessment
Description:
Seismotectonic zoning is one of the elementary blocks of seismic hazard assessment. It is typically used to define areas in which earthquake attributes, such as frequency-magnitude relations, are considered homogeneous, based primarily on local active tectonic characteristics. Yet, seismotectonic zoning can prove a major challenge in Stable Continental Regions where, by definition, active tectonics are extremely subdued. In this study, we develop new seismotectonic models of metropolitan France and neighboring regions of intraplate Western Europe, which will serve for seismotectonic zoning and source characterization for the new probabilisitic seismic hazard assessment (PSHA) for metropolitan France. These new seismotectonic models are based on classical data sets, such as instrumental and historical earthquake catalogs, or crustal structure information, but also on alternative data and information that are not usually considered in intraplate settings. We consider geodetic (GNSS) strain rates derived from several different solutions to help define areas of consistent deformation and tectonic styles. In addition, because the causes of present-day deformation and seismicity are not simply due to plate tectonics, we also consider geodynamic models of alternative driving mechanisms, specifically glacial isostatic rebound from the Weichselian-Würm Glaciation and isostatic response to Quaternary – Holocene erosion and sedimentation rates. These different data sets and models allow us to delineate areas of well-defined tectonic styles and rates (e.g., most of the Pyrenees Mountains) and others where the expected deformation and seismicity are more poorly defined, or where the different data sets are not compatible. The seismotectonic models will in turn be used as input branches for the PSHA logic tree.
Session: Earthquakes, Lithospheric Structure, and Dynamics in Stable Continental Region [Poster]
Type: Poster
Date: 4/17/2025
Presentation Time: 08:00 AM (local time)
Presenting Author: Stephane
Student Presenter: No
Invited Presentation:
Poster Number: 65
Authors
Louise Jeandet louise.jeandet@umontpellier.fr Université de Montpellier |
Hervé Jomard herve.jomard@irsn.fr Autorité de Sureté Nucléaire et de Radioprotection |
Stephane Mazzotti Presenting Author Corresponding Author stephane.mazzotti@univ-nantes.fr University of Nantes |
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New Seismotectonic Models of Metropolitan France and Neighboring Intraplate Regions for Seismic Hazard Assessment
Category
Earthquakes, Lithospheric Structure, and Dynamics in Stable Continental Regions