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Community Velocity Model - SCEC 4.26

CVM-S4.26 is an improved version of the CVM-S4 velocity model which includes full 3D tomographic improvements to the SCEC 4 velocity model as well as an optional GTL implementation. Please note that unlike CVM-S4.26M01, CVM-S4.26 does not "merge" the results of the inversion with an underlying velocity model. Therefore it is strictly the 26th iteration dataset, 500m resolution, tri-linearly interpolated. There is no background model included, although UCVM can tile a background 1D model should the user specifically ask for it.

Naming Convention

At some point in the past, CVM-S4.26 was renamed to CVM-S5. However, this name has led to confusion. So we have reverted to the original names. CVM-S4.26 is the unmodified tomography result from En-Jui Lee and Po Chen.

CVM-S4.26.M01 is a version of CVM-S4.26 that add a geotechnical information from the original CVM-S4. The methodology for adding the GTL layer was developed by Taborda, Gill, and Maechling.

At this time, SCEC has not released a CVM-S5 model.

CyberShake Histogram Plots

Vs30 at CyberShake Sites

Cvms5 vs30.png Cvms4 vs30.png
Cvmh vs30.png

Z1.0 at CyberShake Sites

Cvms5 z10.png Cvms4 z10.png
Cvmh z10.png

Z2.5 at CyberShake Sites

Cvms5 z25.png Cvms4 z25.png
Cvmh z25.png

Material Properties Below 50km

The image below shows depth profiles for all CyberShake sites plotted onto one image. The depth goes from 0km to 500km.

Cvms4 vs cybershake 500km.png

In the two images below, CVM-S4.26 is in red and CVM-S4 is in blue. Currently, CVM-S5 returns the material properties at 50km for all depths below 50km.

Usc500km.png Perris500km.png

Attenuation Relationship

Attenuation is based off of Olsen et al., 2003 and is calculated as follows:

If Vs < 1500:
    Qs = Vs * 0.02
    Qs = Vs * 0.10

Qp = Qs * 1.5

Density Based on Vs

According to Po Chen:

"The Vs-density relation was obtained from Table 1 in Brocher 2005. In that table, the 3rd column is Vs and the 5th column is density. So I did a regression using data from these two columns and obtained a polynomial relation for Vs-density. Those numbers in that data file are the coefficients of the polynomial."

The actual polynomial is:

1.2948318548300342 + 1.2550758337054457Vs - 0.51231936640441489Vs2 + 0.051962399479341816Vs3 + 0.015600987888334450Vs4 - 0.0024189659303912917Vs5

Initial Plots

CVM-S5 0m to 500m with GTL

Cvms5 horizontal 0 gtl.png Cvms5 horizontal 100 gtl.png
Cvms5 horizontal 200 gtl.png Cvms5 horizontal 300 gtl.png
Cvms5 horizontal 400 gtl.png Cvms5 horizontal 500 gtl.png

Depth Profiles

Surface Profiles

Del Amo -118.09624, 33.84822
Delamo cvms5.png
Diablo Canyon -120.85611, 35.21083
Diablocanyon cvms5.png
PERRIS -117.24904, 3380594
Perris cvms5.png
USC -118.286, 34.0192
Usc cvms5.png

60km Profiles

Del Amo -118.09624, 33.84822
Delamo cvms5 60km.png
Diablo Canyon -120.85611, 35.21083
Diablo canyon cvms5 60km.png
PERRIS -117.24904, 3380594
Perris cvms5 60km.png
USC -118.286, 34.0192
Usc cvms5 60km.png

CVM-S4.26 0m to 500m no GTL

Cvms5 horizontal 0 nogtl.png Cvms5 horizontal 100 nogtl.png
Cvms5 horizontal 200 nogtl.png Cvms5 horizontal 300 nogtl.png
Cvms5 horizontal 400 nogtl.png Cvms5 horizontal 500 nogtl.png

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