AUSTIN (KXAN) – On Tuesday, 80 miles south of Austin, a 3.1 magnitude earthquake shook the small town of Nixon, Texas. It was the fourth earthquake in the region in two weeks. Hearing about an earthquake is usually rare in Texas, but it’s not as uncommon as you might think.
So why might the number of quakes be increasing?
First, you need to know how an earthquake happens. Think of it this way, the earth’s crust is like a giant jigsaw puzzle floating atop a hot bowl of soup. Because of that soup, these jigsaw pieces slowly move around, and when they bump into each other an earthquake happens.
The place where these pieces collide is called a fault line. Central Texas happens to have one major fault line running through it. The Balcones Fault starts near Del Rio, runs along I-35, and curves towards Dallas. In fact, this fault formed Mount Bonnell. The Balcones fault is not actively moving, and is considered one of the lowest risk zones for earthquakes in the country.
Dallas, Houston and the panhandle are all near other Texas faults, while West Texas has the most fault zones in the state.
The University of Texas Institute for Geophysics reports Texas has had more than one-hundred earthquakes in the last century. Of those, five have been strong enough to damage buildings, measuring between five and six magnitude.
The Nixon earthquake had an initial reported magnitude of 3.1 and a depth of about three miles. Interestingly, it was the fourth quake with a similar magnitude and depth to occur within two weeks. All four of those quakes were in a part of the state known for fracking, a process in which people inject liquid into the ground to force oil and gas to the surface.
Per the United States Geological Survey, fracking, mining and building dams have all been attributed to induced seismicity, where an earthquake is caused by human activity.
In the south-central United States, a significant number of recent earthquakes are thought to be caused by humans. Human induced activity could lead to an increase in damaging natural earthquakes, but research is still ongoing.
While the Nixon earthquake may be minor, it could be a sign for greater destruction to come.