USGS Earthquakes

USGS Earthquake Hazards API

Real-time and historical earthquake data from the USGS. No authentication required.

Data Model

• Event — An earthquake with magnitude, location, depth, time, and significance.
• Feature — GeoJSON feature wrapping an event with geometry (coordinates) and properties.
• FeatureCollection — A collection of features with metadata (count, API version).

Key Properties

• mag — Magnitude (Richter-like scale). Typically 0-10+.
• place — Human-readable location description.
• time — Event time as Unix epoch milliseconds.
• alert — PAGER alert level: "green", "yellow", "orange", "red" (or null).
• tsunami — 1 if tsunami warning issued, 0 otherwise.
• sig — Significance score (0-3000+). Combines magnitude, felt reports, and damage.
• type — Event type: "earthquake", "quarry blast", "explosion", etc.
• felt — Number of felt reports (null if none).
• mmi — Modified Mercalli Intensity (shaking intensity, 1-12 scale).

Magnitude Types

• ml — Local (Richter), mb — Body-wave, ms — Surface-wave, mw — Moment (preferred for large events).

Gotchas

• Time parameters use ISO 8601 format (e.g. "2025-01-01" or "2025-01-01T00:00:00").
• Maximum result limit is 20,000 events per request.
• Large queries (many events) can be slow — narrow date range or magnitude.
• Coordinates are [longitude, latitude, depth] in GeoJSON geometry.
• Depth is in kilometers (positive = below sea level).