Concepts
The Unified Community Velocity Model (UCVM) software is open-source scientific software designed to support earth scientists, civil engineers, and other groups interested in detailed information about earth properties. UCVM is primarily used by scientists to work with earth material properties on regional scales.
UCVM software provides a software interface to one or more existing earth structure models. Researchers may choose to use the UCVM software, in order to access one or more UCVM specific capabilities, which include:
- Provides standard query interface to multiple CVM models with different projections.
- Converts query by elevation to query by depth to create comparable models.
- Provides standard methods for tri-linear interpolation, Vs30, and basin query from models.
- Provides plotting and analysis tools that make vertical profile, horizontal, and cross section plots.
- Provides tools to add geotechnical layers and small scale heterogeneities into models.
- Supports tiling of models and background models.
- Make AWP and ETree format meshes including parallel extractions.
The SCEC Unified Community Velocity Model (UCVM) software is used to access information, including estimated Vp and Vs seismic wave velocities and density, about the earth's crust.
UCVM provides seismic velocity information for several California regions. Seismic velocities of rocks and sediments at shallow depths determine how strongly an area will shake. By assigning velocities to rock types in the 3-D geologic model, geologists can gain an understanding of the extent of areas of low shear velocity that are most likely to experience localized strong shaking and future earthquake damage. An important application for the models accessible through UCVM is for use in computer simulations of California earthquakes.
The Unified Community Velocity Model (UCVM) software framework is a collection of software tools designed to provide a standard interface to multiple, alternative, California velocity models. UCVM development is an interdisciplinary research collaboration involving geoscientists, computer scientists, and software developers. UCVM is used in high resolution 3D wave propagation simulations for California.
The map below shows the coverage regions for currently supported California velocity models that are accessible through UCVM. Each of the models shown is considered a regional velocity model. Typically the models return values down to about 50km or 100km, but most models are undefined below 100km. For earth material properties below 100km, global seismic velocity models, such as the Preliminary Earth Reference Model (PREM), are possible alternative models.
Map shows coverage region for California CVMs registered into UCVM. Coverage region for UCVM 2D maps (yellow) overlayed upon regions of various California 3D velocity models ( CVM-S4: red, CVM-S4 geotechnical regions: red polygons, CVM-H high resolution: small light blue square, CVM-H low resolution: larger light blue square, USGS High Resolution Bay Area: small white rectangle, USGS Low Resolution Bay Area: large white rectangle, CVM-S4.26, CVM-S4.26M01: green, CCA 06: small yellow, CS17.3, CS17.3-H: large orange rectangle, Havard San Joaquin Basin Model: small orange rectangle, Havard Santa Maria Basin Model: orange square, CS18.5 Cypershake Study's Tiled Velocity Model: blue ) : Coverage.kml
The most recent UCVM software in distributed into a collection of inter-operable software packages.
- This is the UCVM github repository for the UCVM core package that provides the UCVM query interface.
- The velocity models are managed in their own github repositories (e.g. CVM-S4, CVM-H v15.1, CVM-S4.26, CVM-S4.26.M01).
- Specialized UCVM plotting tools can be retrieved from the UCVM plotting package github repository if needed. We expect to release this multi-package version of UCVM in mid-2021.
UCVM is distributed as open-source scientific software. It can be installed compiled and run on most Linux-based computer systems if the system includes software development tools including Python, C, and Fortran compilers, and other software tools. UCVM can be run on other operating systems with use of Docker, a free software that can run containerized version of UCVM. Information about using the Docker version of UCVM can be found in the UCVM Docker images repository.
