API Explorer — Public Endpoints

Returns a list of published earthquake events, newest first. Each event includes the USGS event ID, magnitude, location description, epicenter coordinates, depth, origin time, and the maximum MMI value recorded across all gazetteer sites. Use this endpoint to discover recent events and retrieve their IDs for follow-up queries.

Returns ground shaking intensities at all 531 named gazetteer sites for a specific earthquake event. The default method is shakemap_interpolated, which reads directly from the USGS ShakeMap grid. GMPE methods (ask14, bssa14, cy14, cb14) use physics-based ground motion prediction equations and site-specific Vs30. Use method=all to compare all methods side-by-side (MMI only).

Returns the time-averaged shear wave velocity in the upper 30 meters (Vs30) at any location within the supported region (lat 28–50°N, lon 125–113°W). Vs30 characterizes surface geology and is a key input to GMPE ground motion calculations. The response includes the value and its source: CGS Geology (California geology-based, most accurate), Wald Topography (UCVM) (Nevada/Oregon/Mexico via topographic proxy), Wald Topography (USGS) (raster fallback), or Default (760 m/s) (rock site reference, used when no data is available).

Returns all named gazetteer locations sourced from the GeoNames cities1000 dataset (cities with ≥1,000 residents): 1,114 in California, 401 in Washington, 220 in Oregon, 101 in northern Mexico, 100 in western Idaho/Montana, and 66 in Nevada (2,002 total). Each record includes the site ID, name, lat/lon coordinates, region code, and site-specific Vs30. The optional region parameter filters to a single state or country. Use this endpoint to build your own mapping or analysis tools on top of the Intensity Lab data.