M3.6 earthquake 5 km ESE of Helena, Oklahoma

A magnitude 3.6 earthquake struck 5 km ESE of Helena, Oklahoma on Tue, Feb 17, 2015, 11:13 AM CST (17:13 UTC), 5 km (3 mi) below the surface.

A larger quake followed: M4.1 6 km SE of Marshall, Oklahoma. This one was a foreshock.

Map

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

The USGS’s account of the effects of this earthquake.

Felt (IV) at Helena. Also felt at Aline, Enid, Oklahoma City, Ringwood and Stillwater. Felt at Derby and Wichita, Kansas.

From the USGS event page for usb000tq2k. U.S. Geological Survey text and figures are in the public domain.

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

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

Reviewed by a seismologist.

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

Within 100 km, magnitude 1.5 and up: at least 202 in the 60 days after this one and at least 200 in the 30 days before it.

The first 60 of at least 202.

From the USGS Earthquake Hazards Program and its partner networks, event usb000tq2k. Read Sat, Oct 3, 2026, 6:44 PM UTC.