This is not an early-warning system. It shows earthquakes already reported by USGS — it cannot predict or warn of earthquakes. For official alerts follow the USGS and your local emergency authorities.
Magnitude scale
What each magnitude means in energy and shaking — from micro tremors you can't feel to great quakes, with the Richter vs moment-magnitude story.
Open referenceEarthquake articles
Plain-English explainers: what an earthquake is, the types, how seismic waves and subduction work, aftershocks, safety, and recent major quakes.
Read articlesStay safe
Drop, Cover, Hold On — what to do during the shaking, in the seconds you may get, and in the hours after. A calm, practical checklist.
Safety guide