CVM-S5

Community Velocity Model - SCEC 5

CVM-S5 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.

Material Properties Below 50km

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

Attenuation Relationship

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

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