HighF 2018
This page documents the High-F activities and decisions for the 2018 verification and validation runs for three groups: Olsen et al. (AWP), Graves (RWG) and Taborda et al. (Hercules).
Contents
Mesh generation rules and parameter constraints
Velocities
- 1. Set Min Vs=500 m/s
- 2. If Vs was lower than 500 m/s and adjusted, then adjust Vp with original Vp/Vs ratio (so that we don’t have the automatic Vs/Vp of 3). We may want to set a minimum value of Vp (Rob to check)
- 3. Then set Max Vp/Vs= 3, if lower Vp to maintain the max of 3 ratio
Lame parameters (mu and lambda)
Use mu and Lambda parameters to fix Vp/Vs issues in the CVM where necessary, as part of the mesh generation. Need to make sure that patches are physical and not only to make the codes run.
- Rob to check if raw model produces lambda of <=zero.
- Note: lambda of zero corresponds to Vp/Vs= sqrt(2)=1.45
- Note: typical Vp speeds are 330 m/s in air, 1450 m/s in water and about 5000 m/s in granite
Anelastic attenuation (Q)
Frequency-independent Q definition
- Qs=100*Vs(km/s)
- Qp=2*Qs
Upper frequency
- 5Hz: based on 500 m/s and 20 m spacing
- Kim and Rob have been low-pass filtering the slip function at 5 Hz
- Ricardo and Naeem don’t filter the source
Source Models
We discussed various sources, both point source (PS) and finite-fault (FF) in the past for our verifications and validation.
Various models were run in 2016:
Also ran various smoothed variations of the GP15 FF (need to find a reference for that)
Rob to follow-up with Wei (last communication was in April 2017).
Proposed models for verification and validation:
- PS: model from En-Jui (moment tensor). Can we replicate En-Jui's results? Would need to use CVMS4.26 (cms5) - not desirable. We could perform a check with CVS4.26.M01 at 5 sec. Need to use the same record En-Jui used.
- Lee E.-J., P. Chen, and T.H. Jordan (2014). Testing Waveform Predictions of 3D Velocity Models against Two Recent Los Angeles Earthquakes. Seismol. Res. Lett., 85 (6): 1275–1284.
- FF: gp.5.3.02 [NEED TO UPLOAD Notes from Rob]
Site Selection
Simulation results
Description: results for the small region from November 10 2017:
Description: small region simulations for Hercules, AWP (updated since November 2017) and RWG (medium size model to avoid boundary reflexions):
Description: results for the small region from November 10 2017:
Description: small region simulations for Hercules (updated to use simulations including Q), AWP (updated since November 2017) and RWG (medium size model to avoid boundary reflexions):
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