Difference between revisions of "UCVM Density Formula"
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From these plots, we conclude that CCA and CVM-S4.26 use the same density formula, scaled from Vs. | From these plots, we conclude that CCA and CVM-S4.26 use the same density formula, scaled from Vs. | ||
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| + | We were told CVM-H uses a Vp-based scaling relationship to give a density value based on nafe_drake. We plot density values for selected points extracted from cvm-s4.26, cca06, and cencal. | ||
| + | {| | ||
| + | | [[File:cca_rho_versus_density_1000km.png|thumb|400px| CCA Density (rho) at Depth 1000m (Density in g/cm^3)]] | ||
| + | | [[File:cvms5_rho_versus_density_1000km.png|thumb|400px|CVM-S4.26 Density (rho) at Depth 1000m (Density in g/cm^3)]] | ||
| + | | [[File:cencal_rho_versus_density_1000km.png|thumb|400px|Cencal Density (rho) at Depth 1000m]] | ||
| + | |} | ||
| + | |||
== Density Formula used in CVM-S4.26 and CCA06 == | == Density Formula used in CVM-S4.26 and CCA06 == | ||
Revision as of 06:24, 27 May 2018
We have reviewed how the density values are calculated in our tomography improved velocity models. We have determined that CVM-S4.26 calculated density from model Vs, and CCA06 provides density values in a data file. We reviewed algorithms to confirm that the same algorith is used to calculated density for both CVM-S4.6 and CCA06.
Compare Model Density to Formula Density
If model uses the formula, we'd expect values to fall on a diagonal line in these plots.
From these plots, we conclude that CCA and CVM-S4.26 use the same density formula, scaled from Vs.
We were told CVM-H uses a Vp-based scaling relationship to give a density value based on nafe_drake. We plot density values for selected points extracted from cvm-s4.26, cca06, and cencal.
Density Formula used in CVM-S4.26 and CCA06
# # * Calculates the density based off of Vs. Based on Nafe-Drake scaling relationship. # * # * @param vs The Vs value off which to scale. # * @return Density, in g/m^3. # */ def vs_2_density(vs): # Density scaling parameters p5 = -0.0024189659303912917 p4 = 0.015600987888334450 p3 = 0.051962399479341816 p2 = -0.51231936640441489 p1 = 1.2550758337054457 p0 = 1.2948318548300342 retVal = 0.0 vs = vs / 1000.0 retVal = p0 + p1 * vs + p2 * pow(vs, 2) + p3 * pow(vs, 3) + p4 * pow(vs, 4) + p5 * pow(vs, 5) retVal = retVal * 1000 return retVal
