In recent months, areas of Alabama, Oklahoma, Kansas, Ohio, Colorado, Illinois, Arkansas and Texas have experienced something very unusual for the area: Earthquakes. Because of their distance from major fault lines, these areas were considered the least likely to have significant quakes. But in recent years, they have experienced hundreds. One magnitude 5.1 trembler centered in Oklahoma in February 2016 was felt in seven states, which followed a 4.8 quake in January. Magnitude 3 quakes are routinely experienced now in these areas. In September, a magnitude 5.8 quake hit the central part of the state. While there are sometimes small earthquakes experienced in states like Oklahoma, they are now being experienced hundreds of times more often than before and scientists believe that man’s activities are responsible for the upsurge in quakes, specifically an oil extraction procedure known as “fracking.” While fracking has led to an increase in oil production in the United States and around the world (and subsequent lower energy prices), there have been increasing problems with water pollution and earthquakes from the process.

The rock-solid facts on fracking:

1. Hydraulic fracturing, or fracking, is a process used to pump relatively inaccessible oil out of the ground.

2. In the fracking process, highly pressurized water (usually combined with sand or salts and such chemicals as hydrochloric acid and acetic acid) is aimed into a well to open cracks in the rockbed that will allow oil to flow to the surface.

3. Wastewater from the process is often dumped into disposal wells, changing the geologic pressures of the area; and Oklahoma has more than 3,000 of these disposal wells.

4. More than 1.1 billion gallons of water was injected into Oklahoma wells just in 2013, and geologists with the U. S. Geological Survey believe the wastewater is responsible for the surge of quakes.

5. More traditional pumping techniques rely on the existing high pressures of underground natural gas (produced by the decomposition process that creates oil over millions of years) to force oil out of the ground, not unlike poking a hole in a water balloon.

6. Fracking was first developed in 1947 and has been used increasingly since 2000 to capture oil that had been largely inaccessible.

7. Geologists have warned since the 1960s that fracking and its waste products could cause earthquakes.

8. The water used in the fracking process has also been blamed for increasing problems with contamination of both above ground and underground water sources.

9. While this wave of quakes in Oklahoma has resulted in no fatalities so far, it has caused considerable property damage as well as renewed efforts to study the phenomenon and calls for the process to end or be severely curtailed.

— Dr. Bridges is a professor of history and geography living in Arkansas. He can be contacted at drkenbridges@gmail.com.