Scientists have suspected the the controversial process of fracking, injecting wastewater into the ground to remove oil, was linked to a increase of earthquakes in the general area, but now they are saying they have a direct link, according to ecowatch,com.

A study published in Science, says researchers used satellite images of the earth in eastern Texas to measure ground uplifting from wastewater disposal that eventually caused the 4.8-magnitude quake that hit the area in May of 2012.  That was the largest earthquake that has ever been recorded in that half of Texas.

The imagery showed precise deformations near four high-volume wastewater disposal wells that operated in the area between 2005 and 2007, injecting around 200 million gallons of water per year.  The terrain between two of the wells lifted about 3 millimeters a year on average from May 2007 through November 2010.

The report says the ever-increasing pressure from the water on the spaces in the sub-surface rocks eventually reached the fault zones, resulting in the damaging quake.  A press release from Stanford University said the quakes ended in 2013 after the wastewater injections were reduced dramatically.

Evidence has begun to mount that the fracking process is leading to seismic activity, particularly in areas of Oklahoma, which is today the earthquake center of the country, bypassing California.  A 5.8-magnintude quake struck the area around Pawnee earlier this year and was the largest ever recorded in the state.

According to the article, about two billion gallons of wastewater is pumped into the earth every day, by 180,000 disposal wells sprinkled across Texas, California, Oklahoma and Kansas.

Even after the wastewater injection rates declined, the study noted the seismic activity remained, as the pressure continues to mount from previous injections.

One positive from the study, however, is the research may provide a new tool for determining whether earthquakes are natural or man-made, and may allow scientists to do a better job of predicting them.

Study co-author and geophysicist at Arizona State University, Manoochehr Shirzaei, offered, “This research opens new possibilities for the operation of wastewater disposal wells in ways that could reduce earthquake hazards.  So now the goal, the scope of every scientist across the U.S.A., and maybe abroad, is to make that injection safer.”