Difference between revisions of "UCVM Vs30"

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http://scec.usc.edu/scecpedia/CyberShake_Study_15.12#Vs_values_v2.0
 
http://scec.usc.edu/scecpedia/CyberShake_Study_15.12#Vs_values_v2.0
  
Example Image:
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== UCVM CS173 Model-based Vs30 ==
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http://scec.usc.edu/scecwiki/images/b/b0/S1252_CCA_depth0_horiz_slice.png
 
http://scec.usc.edu/scecwiki/images/b/b0/S1252_CCA_depth0_horiz_slice.png
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== UCVM Etree Vs30 Map ==
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Vs30 from UCVM etree map, based on Willis 2006 map and Wald Topography (outside California)
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File:Vs3 ucvm etree.png
  
  
 
== Related Entries  ==
 
== Related Entries  ==
 
*[[UCVM]]
 
*[[UCVM]]

Revision as of 22:54, 16 May 2018

Introduction

There may be an issue with how UCVM calculates Vs30 values. Presently UCVM uses the following formula:

  1. sum(Vs sampled from [0,30] at 1 meters, for 31 total values) / 31

Rob has suggested that the correct formula should be:

  1. 30 / sum(1 / (Vs sampled from [0, 30) at 1 meters, for 30 total values))

This can have a significant impact for Vs30 calculations. For the BBP1D model, UCVM calculates the Vs30 as 932m/s, whereas Rob's formula calculates it as 862m/s.

Another approach was used in CyberShake Study 15.12, in conversations with Rob:

  1. Vs30 = 30 / Sum (1/(Vs sampled from [0.5,29.5] in 1 meter increments, for 30 total values)).

Points for comparison

We have selected 6 points to compare Vs30 as generated using the CyberShake approach (using half-meters) to other UCVM approaches.

  • Input points for ucvm_query:
-118.1712    34.1484
-118.1250    34.5570 
-118.2860    34.0192
-118.9192    34.6402
-120.3602    36.1397
-119.2285    34.2667


lat lon Velocity model CyberShake-generated Vs30 UCVM 18.5 Vs30 from Model UCVM Vs30 etree.map
34.148426 -118.17119 CVM-S4.26.M01 838.8 821.328 748.00
34.557 -118.125 CVM-S4.26.M01 2573.6 2573.634 497.68
34.0192 -118.286 CVM-S4.26.M01 313.1 310.574 280.0
34.64021 -118.91919 CCA-06 3393.9 3331.251 748.0
36.13968 -120.36015 CCA-06 2277.2 2279.326 349.0
34.26667 -119.22848 CCA-06 902.3 902.013 280.0

Querying cs173 is very slow due to the fine resoultion

To run on max memory on hpc cluster nodes

#!/bin/bash
#SBATCH -p scec
#SBATCH --ntasks=1 #number of tasks with one per processor
#SBATCH -N 1 # number of nodes
#SBATCH --mem 0 # Set to unlimited memory
#SBATCH --time=12:00:00
#SBATCH -o ucvm2mesh_mpi_%A.out
#SBATCH -e ucvm2mesh_mpi_%A.err
#SBATCH --export=NONE
#SBATCH --mail-user=maechlin@usc.edu
#SBATCH --mail-type=END

cd /auto/scec-00/maechlin/ucvmc185/utilities
srun -v --mpi=pmi2 /auto/scec-00/maechlin/ucvmc185/utilities/plot_vs30_map.py -b 30.5,-126.0 -u 42.5,-112.5 -s 0.01 -a s -c cs173 -o vs30_cs173.png
-bash-4.2$ 

== Related Links: Plot command used to plot_vs30_map. ./plot_vs30_map.py -b 30.5,-126.0 -u 42.5,-112.5 -s 0.05 -a s -c cs173 -o vs30_cs173.png

Scott posted vs30 values from CyberShake here: http://scec.usc.edu/scecpedia/CyberShake_Study_15.12#Vs_values_v2.0

UCVM CS173 Model-based Vs30

S1252_CCA_depth0_horiz_slice.png

UCVM Etree Vs30 Map

Vs30 from UCVM etree map, based on Willis 2006 map and Wald Topography (outside California) File:Vs3 ucvm etree.png


Related Entries