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SIGMA3: A Further Step for the Reduction of Epistemic Uncertainties in PSHA

Description: 

Today, the evaluation of seismic hazard and risk at critical facilities, such as nuclear installations, often relies on probabilistic site-specific approaches for return periods of 10,000 years, or more. In this context, this type of results is very dependent on the knowledge of local site conditions (i.e., geology, soil response) and on the level of uncertainties in the components of the seismic source model (SSM) and in the ground-motion model (GMM). This situation is heightened in low-to-moderate seismicity areas due to data scarcity or to large uncertainties in the models.

The research program SIGMA3 has been launched in 2024 over a period of 5 years to overcome such difficulties by developing data, methods and models that will contribute to the reduction of epistemic uncertainties in seismic hazard assessment (SHA). We aim at working with the largest international community of researchers and to improve our practices for hazard assessment and safety demonstration based on consensus.

Our poster will introduce the main technical orientations of the program, which are also grounded on the results of the two previous SIGMA and SIGMA2 programs. Work Package (WP) 1 will coordinate research actions (RA) to improve the quality of earthquake catalogues and active faults databases. WP 2 will organize RA for the modelling of ground-motion (GM) and to pursue the quest for reference GMM, devoid of any spurious (de-)amplification effects. WP 3 will organize RA on soil dynamics and non-linear site response. WP 4 will conduct RA to improve the PSHA methodology, both for calculation efficiency and for the propagation of uncertainties. Frameworks for the introduction of all available information will also be developed to enable to obtain better informed hazard models (e.g., instrumental, historical, paleo-seismological…). Finally, WP 5 will develop a virtual simulation platform for the generation of synthetic seismicity and ground-motion data for PSHA purposes. By simulating reality, we want to better understand what we observe in the models and in PSHA outcomes.

Session: Testing, Testing 1 2 3: Appropriate Evaluation of New Seismic Hazard and Risk Models [Poster]

Type: Poster

Date: 4/15/2025

Presentation Time: 08:00 AM (local time)

Presenting Author: Paola

Student Presenter: No

Invited Presentation: 

Poster Number: 70

Authors