USGS Earthquake Hazard & Historical Activity Lookup

Choose this endpoint when you need authoritative USGS probabilistic seismic hazard values alongside historical earthquake event data for a specific US address or coordinate pair — especially for real estate due diligence, insurance underwriting, or emergency planning. It combines two USGS data sources (Seismic Design Maps and FDSN Event Web Service) in a single call. Prefer it over generic hazard aggregators when you specifically need earthquake-focused USGS data; for a combined multi-hazard score (flood, wildfire, wind, etc.) consider the sibling insurance location risk score endpoint instead.

• Address cannot be geocoded — returns null or error for resolvedAddress
• Coordinates fall outside US coverage area — USGS data may be unavailable
• No historical earthquake events found for sparse or low-activity regions — historicalActivity returns empty array
• Invalid input schema — missing or malformed lat/lon or address parameter
• Payment failure — x402 micropayment not completed, endpoint returns 402 status
• USGS upstream API unavailable — service may return error or partial data