EDGEFIELD - Parts of Northwest Louisiana were shaken by an unexpected wake-up call early Thursday morning as a 4.9-magnitude earthquake struck near the town of Edgefield.

The U.S. Geological Survey (USGS) reported the quake occurred at 5:30 a.m., centered approximately 4.4 miles northwest of Edgefield and roughly 29 miles northwest of Natchitoches. While the epicenter was located about 173 miles from Baton Rouge, the tremor was felt across a wide swath of the state and into East Texas.

It is one of the largest recorded earthquakes in state history, and has many wondering what could have caused it. Geologists say it's unusual for Louisiana to experience these kinds of earthquakes, but they could be becoming larger and more frequent.

"The number and the magnitude of these earthquakes have been steadily increasing, and over the past year, we've started to get bigger earthquakes," Tulane Geosciences Professor Cynthia Ebinger said.

Researchers at LSU say that a Seismometer, which is a device placed underground to detect seismic activity, helped them detect the earthquake from hundreds of miles away.

"We have them distributed all over the world, and that's how we do our science. An earthquake of this size is actually strong enough that the waves will have traveled around the whole globe," LSU Department of Geophysics Associate Professor Karen Luttrell said.

Luttrell says that the reason it's uncommon to see this level of earthquake in Louisiana is because of its location.

"We mostly associate earthquakes with the edges of tectonic plate boundaries. So think like the San Andreas Fault. We are in the middle of a tectonic plate. The North American tectonic plate, and so we are not in an area where there is active plate deformation," Luttrell said.

As for what Geologists believe could be a cause for the earthquake and the increased frequency of earthquakes in Louisiana, Ebinger points to a similarly sized earthquake that occurred in Eastern Texas in 2012.

"There are scientists who have done a lot of studies, and they found that a fault system beneath the basin, an ancient fault system, was reactivated and that it slipped during the earthquakes. That's what probably most likely has happened here as well," Ebinger said.

Ebinger did say that they've seen cases in states like Texas and Oklahoma with similar patterns, where earthquakes were caused by large amounts of wastewater injection that was associated with the oil and gas industry.

"It's possible that the increase is related to 10 to 15 years of increased volumes of wastewater injection, and it's something that the state will look at. We're seeing it build up so quickly; it's probably accelerated. It might have been another 200 years, maybe before this happened, but we're getting more rapidly," Ebinger said.

Ebinger says there have already been multiple aftershocks on Thursday. Two of them were recorded at 2.9 and 2.7.

"With an event of this size, we probably can expect maybe some smaller magnitude earthquakes to go on for perhaps about a week or so. A few weeks," LSU Geology and Geophysics Assistant Professor Brandon Shuck said.