It’s been less than two weeks since the latest earthquake shook the ground near Timpson, Texas. Four stronger quakes struck within a seven mile radius of Timpson this spring. Now that the dust has settled for the moment, we’re taking a look at what’s shaking in Timpson – why all the earthquakes?

Matt Hemingway from the Shreveport National Weather Service says the recent quakes in east Texas are part of a longterm pattern of occasional flareups of seismic activity along a weak fault line in east Texas.

"Historically, there have been earthquakes there as far back as the 1800s," Hemingway said.

The first recorded quake of 3.0 magnitude or higher in east Texas happened in January 1881. Since then, periods of seismic activity have occurred.

For example, one of the strongest quakes ever recorded in east Texas happened in 1957. A 4.7 magnitude quake struck near Diana, Texas, which is north of Longview.

In 1964, eight earthquakes struck within a five month span from April to August. That's the highest number of quakes recorded in east Texas in a single year - nearly double the number of this year's quakes.

Hemingway said the periods of seismic activity have been spread out, so when the earthquakes happen along the weak east Texas fault line, they are unexpected.

"They take people by surprise, because they happen so infrequently," Hemingway said.

The area had gone 30 years without significant seismic activity until five earthquakes struck near Timpson this spring. The strongest was a 4.7 magnitude quake that rattled houses and caused some damage to buildings. Surveillance video footage from a store in Timpson showed the ground shaking and items falling off the shelves when the quake struck in the early morning of May 17.

Some have speculated about whether the recent earthquakes are caused by fracking. Fracking is the technique of extracting petroleum or natural gas by drilling into rock formations beneath the earth's surface. 

Hemingway said there is not enough evidence to suggest that fracking in the area is causing the east Texas quakes.  He noted the technique has been implemented only in the past several decades, while records of earthquakes date back more than 130 years.

Here's a list of earthquakes that have struck near Timpson this year:

May 10: A 3.9 magnitude quake struck two miles west of Timpson.
May 17: A 4.8 magnitude quake struck four miles east of Timpson.
May 20: A 2.7 magnitude quake struck two miles southwest of Timpson.
May 26: A 2.5 magnitude quake struck seven miles southeast of Timpson.
June 16: A 2.1 magnitude quake struck three miles southwest of Timpson.

For detailed information on earthquakes in Texas, visit the USGS website.