M3.5 earthquake 9 km ESE of Jefferson, Oklahoma

A magnitude 3.5 earthquake struck 9 km ESE of Jefferson, Oklahoma on Sun, Aug 22, 2021, 5:42 AM CDT (10:42 UTC), 5 km (3 mi) below the surface.

A larger quake followed: M3.8 7 km E of Nescatunga, Oklahoma. This one was a foreshock.

Map

Where this earthquake was located, with the others nearby. Select one for its page.

The USGS ShakeMap: shaking estimated from seismic stations and the quake’s size, on the Modified Mercalli intensity scale.

16 people reported to the USGS what they felt; the strongest reported shaking was V, moderate shaking.

How the rock slipped, from the moment tensor, and the USGS estimate of landslides and liquefaction.

Reviewed by a seismologist.

Distance and direction from each place to the epicenter, with its forecast.

Within 100 km, magnitude 1.5 and up: 80 in the 60 days after this one and 31 in the 30 days before it.

The first 60 of 80.

From the USGS Earthquake Hazards Program and its partner networks, event ok2021qknk (also filed as us6000f9ly). Read Tue, Sep 22, 2026, 7:51 PM UTC.