About
About QuakeWatch.US
An open, public-facing window into United States seismic activity — built on authoritative USGS data and designed for clarity, not alarm.
How it works
1
Detect
Seismometers nationwide record ground motion and feed the USGS network.
2
Locate
USGS computes each event's magnitude, depth, and epicenter, often within minutes.
3
Surface
We pull those feeds in real time and plot every U.S. event on the live map.
4
Inform
Browse, filter, and subscribe to alerts so you stay aware of activity that matters to you.
Understanding magnitude
< 3.0Micro to minor — usually not felt, recorded by instruments.
3.0 – 3.9Often felt, rarely causes damage.
4.0 – 4.9Noticeable shaking; minor damage possible near the epicenter.
5.0 – 5.9Can damage poorly constructed buildings over small regions.
6.0+Strong to major — capable of serious damage across populated areas.
Frequently asked
Where does the data come from?+
How quickly are events posted?+
Is this an official warning system?+
What area is covered?+
QuakeWatch.US is an informational reference and not an official emergency warning system. Magnitudes and locations are preliminary and subject to revision by the USGS. In an emergency, call 911.