(WUSA9) -- Fracking has become a highly controversial practice in the U.S. On one hand, it's extracting a large amount of domestic oil and creating jobs. On the other hand, the hydraulic process used to get that oil out of the ground may be causing problems.
The Wall Street Journal is reporting on a new study from the journal "Earth and Planetary Science Letters." It finds so much oil and water is being removed from the "Eagle Ford Shale" in Texas, that the activity has probably led to a recent wave of small earthquakes.
The authors suggest that taking oil and water out of the ground allows surrounding rock and sand to settle, possibly contributing to those small tremors.