In the past three weeks, there have been five earthquakes recorded in our listening area. All of them have been centered near the Alabama/Florida state line, near Flomaton and Century. The Geological Survey of Alabama has described these quakes to al.com as falling within the realm of "normal seismic activity." In other words, it's not uncommon for an area to have one earthquake, and then several more in short order.
But it may not be as simple as all that, and now government researchers want to know if the earthquakes have been "induced" by the area's oil and gas industry. I wrote about this possibility a couple of weeks ago:
Some human activities can cause earthquakes; and according to one paper, wastewater disposal is a main culprit for a dramatic increase in earthquakes in the Central United States. Wastewater is a common byproduct of enhanced oil drilling methods, and it will often get pumped back into the ground after being pulled to the surface. This is where we should note that the area where these small earthquakes have occurred is also a key player in Florida's oil and gas industry. It's home to the Jay oil field, which was discovered in 1970. The area's long history with oil and gas production continues today.
The Gulf Coast Just Had Its Third Earthquake in a Week
The increase in seismic activity has been dramatic in the Central United States. Between 1973 and 2008, there was an average of 24 quakes per year. But between 2009 and 2014, the average shot up to 193 earthquakes each year. Researchers note that there's now a lot more drilling wastewater being pumped back into the ground, much of it a byproduct of the oil and gas industry, and that's the primary reason for the increase in earthquakes.
Researchers suspect that the earthquakes in our area are human induced, as well. According to al.com, the area is one that's already been identified by the US Geological Survey (USGS) as seeing an increase in seismic activity due to oil and gas industry activity. Now the USGS is deploying seismometers in the area, hoping to better understand what's happening.
To read more about how wastewater can cause earthquakes, read this Washington Post story that details the work of scientists at both USGS and the Geological Survey of Canada.
And al.com has also written about the possibility of fracking being a potential cause of the five earthquakes.