Ground Motion Models Uncertainties and Variability: The Impact of Seismic Station Installation Conditions
Description:
In the framework of ground motion and seismic hazard assessment in low to moderate seismic activity regions, the use of locally recorded ground motions has grown in popularity in these last years. Such ground motions allow for example to adjust to the local context existing Ground Motion Models (GMMs) developed in active regions of the world, to develop specific non-ergodic GMM or to perform Generalized Inversions (GIT) and assess seismological models.
When developing GMMs, it is generally assumed that ground motions are recorded in free-field condition, i.e. at the ground surface and far enough from any structure or construction that could interact with and affect the motion. However, when looking closer, there is a wide variety of sensor installation configurations and conditions worldwide. Nonetheless, information about seismic station installation conditions (housing, type of soil-sensor coupling…) is most often lacking in ground motion databases.
In this context, with the objectives of identifying possible biases and robustly characterizing variabilities associated to GMMs, this work illustrates the impact of the “free-filed assumption” on site-to-site variability and the benefit of accounting for the information about seismic station installation conditions in the development of empirical GMMs. For this, a simple GMM based on EPOS-France ground motion dataset (Buscetti et al., 2024) is developed, accounting for available information on the sensor installation conditions. The results highlight that a significant portion of the site-related variability in the GMM is due to the variety of sensor installation modalities and conditions inventoried in France. Accounting for these metadata allows to improve the description of the GMM variability by an enhanced separation of repeatable and aleatoric effects. Overall, this contributes to the improvement of seismic hazard studies accuracy.
Session: Station Installations and Site Conditions, a Quest for Improved Strong Motion Database - II
Type: Oral
Date: 4/16/2025
Presentation Time: 05:15 PM (local time)
Presenting Author: Paola
Student Presenter: No
Invited Presentation:
Poster Number:
Authors
Paola Traversa Presenting Author Corresponding Author paola.traversa@edf.fr Electricity of France |
Fabrice Hollender fabrice.hollender@cea.fr French Alternative Energies and Atomic Energy Commission, University of Grenoble Alpes, Institute of Earth Sciences |
Pauline Rischette pauline.rischette@cea.fr French Alternative Energies and Atomic Energy Commission, University of Grenoble Alpes, Institute of Earth Sciences |
Margaux Buscetti margaux.buscetti@cea.fr French Alternative Energies and Atomic Energy Commission, University of Grenoble Alpes, Institute of Earth Sciences |
Vincent Perron vincent.perron@cea.fr French Alternative Energies and Atomic Energy Commission, University of Grenoble Alpes, Institute of Earth Sciences |
|
|
|
|
Ground Motion Models Uncertainties and Variability: The Impact of Seismic Station Installation Conditions
Session
Station Installations and Site Conditions, a Quest for Improved Strong Motion Database