Program for computing seismic hazard

Sigma0 in GMPMs

Sigma0 in GMPMs

  • 151 Views
  • Last Post 04 May 2020
  • Topic Is Solved
OSCAR RODRIGUEZ posted this 02 May 2020

Dear R-CRISIS team,

I'm not sure the meaning of the check field "Sigma0" that appears in the "Attenuation Model Selection" window when I want to apply a GMPM as the Abrahamson 2014 and Campbell 2014 ones. I appreciate you explanation about the purpose of theses check box. In the case where I want to run a "no truncated" model, what would be the selection on these two models? In the case of the others models, "no truncation" condition is set with "Sigma truncation = 0". Is this correct?

Thanks so much,

Oscar Rodriguez

Order By: Standard | Newest | Votes
Content_Manager posted this 04 May 2020

Dear Oscar,

The Sigma 0 checkbox is used in those cases where the PSHA calculation is carried out with a sigma 0.0 GMPEs. As you know, the GMPEs are treated as random variable with a mean and a standard deviation. If the Sigma 0 is checked, that probability distribution will have sigma 0.0.

If you desire to run a "no truncated" model, the Sigma 0 has to be unchecked this reffers to a different concept.

 

Thank you for your preference and interest in R-CRISIS.

 

Best regards,

  • Liked by
  • OSCAR RODRIGUEZ
OSCAR RODRIGUEZ posted this 04 May 2020

Dear Sebastian,

Thanks a lot for your help. It is something that is appreciable when the numbers of standard deviations is reduced progressively for a given model. In this case (checked Sigma 0) the Amax would correspond to the mean of the  model lognormal distribution, isn't it?

Best,

Oscar Rodríguez.

Content_Manager posted this 04 May 2020

That is correct Oscar.

  • Liked by
  • OSCAR RODRIGUEZ
Close