Small Earthquake Shakes Oklahoma City
Map of earthquake location today (Apr. 7, 2014) near Oklahoma City, Oklahoma.
Credit: USGS.

An earthquake of preliminary magnitude 4.0 struck today (April 7) near Oklahoma City, according to the U.S. Geological Survey (USGS).

The temblor's epicenter was 3 miles (6 kilometers) south-southwest of Langston, Okla., and 31 miles (16 km) north-northeast of Oklahoma City. It originated 3.2 miles (5.2 km) deep and struck at 11:03 local time (1603 UTC), the USGS reports.

Oklahoma has seen an uptick in seismic activity in recent years, which scientists believe is the result of fracking-linked wastewater injection.  Since 2009, earthquake activity in the state has been about 40 times higher than in the previous 30 years, according to the Oklahoma Geological Survey. Just in the past week, more than 30 earthquakes over magnitude 2.5 have been measured in Oklahoma, according to data form the USGS.

Some light to moderate shaking was reported in the Oklahoma City area during today's tremor, according to the USGS. Earthquakes of this size typically do not cause damage and there were no immediate reports of harm.

The damage caused by any single earthquake depends on its depth, proximity to populated areas, building standards in the region, as well as the type of earthquake. The USGS frequently updates the magnitude of an event after more data is analyzed.

An earthquake's magnitude is a measure of the energy released at the source. It is just one predictor of the shaking that may ensue, which is affected by local and regional geology. Scientists know in a general sense what causes Earthquakes but are unable to predict specific quakes.

This article will be updated if significant additional information becomes available. Find more earthquake news here.