CyberShake Software Plan
We are currently development CyberShake 2.0 that will have the following capabilities:
- UCERF2.0-based extended earthquake rupture forecast
- 1.0Hz reciprocity-based seismogram synthesis using 3D velocity model
- Addition of 10Hz stochastic to 1Hz deterministic seismograms
- Spectral acceleration calculation
- OpenSHA plotting of hazard curves
Our immediate CyberShake goal is to calculate deterministic 3D seismograms up to 1.0Hz using SRF-format ruptures using both wave propagation simulations and reciprocity-based seismogram synthesis.
We plan to base our forward CyberShake deterministic simulations on the latest Olsen/Roten version of AWP-ODC which was used in the M8 wave propagation simulations. This code is available for use.
SGT codes
A large fraction of our CyberShake computing time is spent calculationg SGTs. Our current plan is to use a new version of AWP-ODC, called AWP-ODC-SGT, to calculate our SGT. We plan to continue to use the Graves seismogram synthesis to calculate seismograms from CyberShake SRF's and AWP-ODC-SGT SGTs.
The current design concept is that we will develop a version of AWP-ODC-SGT that outputs SGT's in the Graves SGT code format. Then, the current Graves seismogram synthesis code will use these SGT's, regardless of the fact they were calculated by AWP-ODC-SGT.
To get this system working, we have modified AWP-ODC-SGT to write SGTs. We are now working to compare the SGT's output by Graves code to ones from AWP-ODC-SGT.
We are seeing again that we need to do this code comparison step-by-step, establishing matching results on simple problems, then adding complexity and comparing again. Here are the proposed simulations that we will compare.
We currently think it is possible to use the current CyberShake seismogram synthesis code from Rob Graves.
Our plan is to convert AWP-ODC-SGT so that it writes SGT files that are identical in format and content to the current Graves SGT files.
0. Modify CyberShake codes to output velocities. 1. Homogenous volume, 30km x 30km x 30km (small region), output stresses and compare 2. 1D model volume output stresses and compare 3. 1D model output velocities and compare 4. 3D model output stresses and compare 5. Implement SGT and fault region management in awp-odc so Graves seismogram synthesis can find SGT's in SGT data sets. 5. seismogram synthesis of point sources and compare 6. seismogram synthesis of SRF source and compare
Extended Earthquake Rupture Forecast
We will extend our current UCERF2.0 rupture generator to produce an UCERF2.0-based set of rupture variations in Standard Rupture Format that contain frequencies up to 1.0Hz.
We require an updated set of fault geometries at higher resolution to support the increase from 0.5Hz to 1.0Hz.
