UCVM 14.3.0 Tutorial

Introduction

UCVM includes many utilities for exploring velocity models for various research purposes. This page describes a couple of very common use cases and how to accomplish them within the UCVM framework.

UCVM includes many utilities for querying velocity models for various research purposes. The following example describes a common use of UCVM. This instructions assume UCVM installed to /home/scec/ucvm-15.10.0, as in the virtual box image.

Querying Material Properties

In order to get material properties from any model, you simply need to run the cvm_query utility for model CVM-S4 (cvms)

cd /home/scec/ucvm-15.10.0/bin
./ucvm_query -f ../conf/ucvm.conf -m cvms

UCVM prints "Using Geo Depth coordinates as default mode"

The user input queries at in decimal degrees and depth in meters. (e.g. -118.0 34.0 at 0m depth)

-118.0 34.0 0 

Carriage return, then control D and UCVM will then return:

-118.0000 34.0000 0.000 280.896 390.000 cvms 696.491 213.000 1974.976 none 0.000 0.000 0.000 crust 696.491 213.000 1974.976

This means that according to the CVM-S4 model, at -118,34, 0 meters depth, the Vp is 696.491, Vs is 213.00, and Rho (density) is 1974.976. You can query any point with any model (cvms, cvmsi, cvmh, cencal) to see what the material properties are at that latitude, longitude, and depth.

The above query is "by depth" meaning that we are querying from the surface level down. To query by elevation, add the flag "-c ge". Therefore, to query the Central California velocity model, we would do:

./ucvm_query -f ../conf/ucvm.conf -m cca -c ge

The full model list is below.

CVM-H - cvmh
CVM-S4 - cvms
CVM-S4.26 - cvmsi
CVM-S5 - cvms5
CCA - cca
USGS Bay Area - cencal
1D Hadley Kanamori - 1d
Broadband Whittier Narrows 1d - bbp1d

One of the best benefits of UCVM is that it allows you to query underlying velocity models in a standardized format. In order to get material properties from any model, you simply need to run the ucvm_query utility. This utility is located in /path/to/ucvm-14.3.0/bin.

cd /path/to/ucvm-14.3.0/bin
./ucvm_query -f ../conf/ucvm.conf -m cvms
Using Geo Depth coordinates as default mode.
-118 34 0 [USER INPUT: Queries -118, 34 at 0m depth]

UCVM will then return:

-118.0000 34.0000 0.000 280.896 390.000 cvms 696.491 213.000 1974.976 none 0.000 0.000 0.000 crust 696.491 213.000 1974.976

This means that according to the CVM-S4 model, at -118,34, 0 meters depth, the Vp is 696.491, Vs is 213.00, and Rho (density) is 1974.976.

You can query any point with any model (cvms, cvmsi, cvmh, cencal) to see what the material properties are at that latitude, longitude, and depth.

Generating Z1.0 and Z2.5 maps

Generating Z1.0 and Z2.5 maps are easy with the included plotting scripts.

Simply go to /path/to/ucvm-14.3.0/utilities and run the z10.py script like:

./z10.py

This script will then interactively walk you through a series of questions. It will then retrieve the data and ask you if you want to save it to a text file or if you want to display it. Simply enter the option to display it to see the map. You will be able to save the image once it displays on your screen.