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**Regional Hazard Simulation (R2D, rWhale) / Re: About UCERF3 Earthquake Scenario Simulation**

« **on:**May 25, 2023, 02:56:28 AM »

from the developer:

Kuanshi Zhong

Fri, May 19, 11:54 AM (5 days ago)

to me

Hi Frank,

We're using the UCERF3 - TD (time dependent). The time dependence probability of a rupture in UCERF3-TD model is conditional on a time duration - so when output the mean annual rate, OpenSHA converts the time-dependent rate to time independent rate (please see more details in the "Example of Coverting Time-Dependent Probability into an Effective Time-Indpendent Rate" on the page 2 of this OpenSHA's tech note: https://opensha.org/resources/PSHA_Primer_v2_0.pdf).

I think you've directed the user to the "FetchOpenSHA.py" - he should be able to find that Line 218 invokes getMeanAnnualRate() in OpenSHA (https://github.com/opensha/opensha/blob/8a65cdc9ad27f5c3245688759f6c687ee95eff15/src/main/java/org/opensha/sha/earthquake/ProbEqkRupture.java#L57) to do the above conversion. Just checked that the time span duration used is 30 years.

Kuanshi Zhong

Fri, May 19, 11:54 AM (5 days ago)

to me

Hi Frank,

We're using the UCERF3 - TD (time dependent). The time dependence probability of a rupture in UCERF3-TD model is conditional on a time duration - so when output the mean annual rate, OpenSHA converts the time-dependent rate to time independent rate (please see more details in the "Example of Coverting Time-Dependent Probability into an Effective Time-Indpendent Rate" on the page 2 of this OpenSHA's tech note: https://opensha.org/resources/PSHA_Primer_v2_0.pdf).

I think you've directed the user to the "FetchOpenSHA.py" - he should be able to find that Line 218 invokes getMeanAnnualRate() in OpenSHA (https://github.com/opensha/opensha/blob/8a65cdc9ad27f5c3245688759f6c687ee95eff15/src/main/java/org/opensha/sha/earthquake/ProbEqkRupture.java#L57) to do the above conversion. Just checked that the time span duration used is 30 years.