Probabilistic Seismic Hazard Analysis (PSHA) - Identification of area sources

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In conducting Probabilistic Seismic Hazard Assessment (PSHA) in Brazil, determining the appropriate radius for seismic source identification is crucial. Recommendations vary, with some sources suggesting a radius of up to 500 km, while others advocate for 200-300 km based on mapped faults. There are also instances of studies employing a 1000 km radius. However, it is noted that high-magnitude earthquakes may not produce significant ground motion beyond 100 km due to attenuation effects observed in Ground Motion Prediction Equations (GMPEs). The reference NUREG/CR-6372, Vol. 1 is highlighted as a valuable resource, and there is a call for additional references or best practices in this area.
Luiz1304
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Hello everyone!
I'm currently working on Probabilistic Seismic Hazard Assessment (PSHA) in Brazil and have a question regarding the appropriate radius for seismic source identification. When calculating Peak Ground Accelerations (PGA) or spectral accelerations for a specific study area, what source-to-site distance should I consider for identifying relevant seismic sources?

I've encountered recommendations for intraplate tectonic regions like Brazil and the Eastern US. Some references suggest a radius of up to 500 km from the study area, with others to 200-300 km based on criteria like mapped faults. However, I've also seen studies using a 1000 km radius.

I think in a 1000 km radius is that even high-magnitude earthquakes might not generate significant ground motion at large distances, given the attenuation observed in Ground Motion Prediction Equations (GMPEs). Some GMPEs, that we use, show low acceleration levels beyond 100 km epicentral distance.

NUREG/CR-6372, Vol. 1, is a great reference i am using, but i would like to know if someone has seen other references or best practices for this kind of study

thank you all!
 
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