A minor earthquake shook the Oklahoma City area on June 18, 2014.
An earthquake of preliminary magnitude 4.1 struck today (June 18) near Oklahoma City, according to the U.S. Geological Survey (USGS).
The temblor's epicenter was 6 miles (9 kilometers) north of Spencer, Oklahoma, and 12 miles (20 km) northeast of Oklahoma City. It originated 3.1 miles (5 km) deep and struck at 5:53 a.m. local time (1053 UTC), the USGS reports.
While most of North America east of the Rocky Mountains rarely experiences earthquakes, Oklahoma has seen an uptick in seismic activity in recent years, likely triggered by fracking-linked wastewater injection, scientists believe.
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. In just the last week, 21 earthquakes over magnitude 2.5 have been measured in Oklahoma, data from the USGS show.
Some light 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.