CVM Repository Interface Guide

Welcome to the repository for the CRESCENT Community Velocity Model (CVM). This platform facilitates access to a wide array of velocity models developed as part of the CRESCENT project. The CVM-Web interface offers advanced visualization tools for model previews and tools for extracting model data. These models are compatible with the Python 3 tools available from the CVM-Tools repository.

To explore the models in the repository, click on any model listed below. Detailed metadata for that model will be displayed, and the 3D map will show the model's boundaries along with current Community Fault Model (CFM) data, such as CRESCENT Cascadia fault traces, fault surfaces, the Cascadia subduction interface, and area seismicity.

Use the download link in the model Summary to download the model's netCDF file.

Click on Show/Hide Filter & Model Coverage Comparison Controls to:

• display filters that allow you to narrow down the models based on the area, depth, and parameters of interest.
• select up to five models for comparison. The selected models will display their area of coverage boundaries on the map, allowing you to visually compare the extent and overlap of each model. This tool helps in analyzing how different models represent geographical areas and their boundaries.

Click on Show/Hide 2D Models to:

• display a list of the available 2D models.
• click on any model to view metadata for that model and display its surface on the 3D map.

Model Resolutions:

Each model has its own native resolution, which is described by the `geospatial` global attributes in the netCDF file. You can view the metadata, including resolution details, by clicking on any model listed below.

The horizontal resolution is determined by the geospatial_lat_resolution and geospatial_lon_resolution attributes, which specify the spacing between grid points in the latitude and longitude directions, respectively. The vertical resolution is defined by the geospatial_vertical_resolution attribute, indicating the spacing in the depth or height dimension.

The geographic extent of the model is outlined by the attributes geospatial_lat_min, geospatial_lat_max, geospatial_lon_min, geospatial_lon_max, as well as geospatial_vertical_min and geospatial_vertical_max. These attributes define the model's boundaries in terms of latitude, longitude, and vertical dimensions.

For example, a model with a latitude resolution of 0.5°, a longitude resolution of 0.5°, and a vertical resolution of 10 meters would have a grid with a horizontal resolution of 0.5° x 0.5° and a vertical resolution of 10 meters. These attributes ensure that the model's spatial resolution and extent are clearly defined for users.

Visualization Tools:

• Cross-Section Viewer: View and analyze vertical cross-sections of the velocity models.
• Horizontal-Slice Viewer: Generate horizontal slices of the models.
• Depth-Profile Viewer: Generate depth profile plot at a given point from a model.

Data Extraction Tools:

• Volume Data: Extract and download 3D volume data from the velocity models.
• Cross-Section Data: Retrieve data for specific vertical cross-sections.
• Depth Slice Data: Access data for horizontal slices at varying depths.

Key features of the interface map include:

• Show/Hide Controls: Use this button to display or hide the map controls.
• CRESCENT Study Area: The boundaries of the CRESCENT study area are outlined in cyan, demarcating the focus area of the study.
• 3D Model Outline: The 3D outline of the selected CVM model is displayed in cyan, allowing users to visualize the spatial extent and orientation of the model within the study area.
• Selected Model Extent: The selected model extent is shown in blue and can be adjusted using latitude, longitude, and depth (if available) sliders. Additionally, an Opacity Control slider is available to adjust the opacity of the model extent display, where 0 represents full transparency and 1 represents full opacity. This provides flexibility in visualizing underlying features.
• Earthquakes Visualization: The yellow dots on the map represent earthquakes with a magnitude greater than 4 that have occurred within the CRESCENT study area since 1970. The size of each yellow dot is proportional to the earthquake's magnitude, with larger dots indicating stronger earthquakes. This earthquake data is sourced from the ANSS Comprehensive Earthquake Catalog (ComCat), which compiles seismic events from various global and regional networks. The data is obtained through the USGS FDSN Event Service, ensuring up-to-date and accurate information on seismic activity. For more details on ComCat, visit ANSS ComCat, and for querying seismic data, visit the USGS FDSN Event Service.
• Imagery Layer: The imagery layer option (when checked) displays an imagery layer available through Cesium, offering detailed and reliable backgrounds for the visualization of geological and seismological data. Users may select different imagery layers using the imagery selection tool located at the top right of the interface.
• Terrain Occlusion Checkbox: Since imagery layers displayed on the map (when selected) are not transparent, the Terrain Occlusion checkbox helps unhide the data displayed on the map. Enabling this feature helps to understand the spatial relationships between the terrain and the subsurface models.
• Feature Toggles: The interface includes checkboxes that allow users to turn on and off various features displayed on the map. This includes toggling the visibility of fault traces, earthquake data, and other model elements, providing flexibility in data visualization and analysis.
• Center View Button: The Center View button allows users to quickly center the map view on the CRESCENT study area or other areas of interest, making navigation easier and more efficient.
• Home View Button: The Home View button resets the map view to its initial default settings, providing a convenient way to return to the original perspective and overview of the map.
• Distance Measuring Tool: The distance measuring tool, located under the map legend and can be activated by checking the Measure Distance checkbox. This tool allows users to click on the map to select two points and measure the distance between them. When the first point is clicked, a point is placed at that location, and the second click places the second point. After both points are selected, a line is drawn connecting them, and the distance between the points is calculated and displayed. The distance is shown in kilometers in a designated display area. If more points are clicked after the second point, the previous line and markers are cleared, and the process starts over. This tool is designed to provide quick and easy measurement of distances between two locations on the map, with visual feedback through markers and lines. Additionally, the user can reset the tool by using a checkbox, which will clear the markers and distance line for a new measurement.