Researchers in Texas have pointed to widespread oil and gas drilling over several decades as the cause of new ground movement in the western part of the state—leading to concerns that the area is at risk for the formation of new sinkholes.
Four counties in West Texas have been "punctured like a pin cushion with oil wells and injection wells since the 1940s," said Jin-Woo Kim, a scientist at Southern Methodist University, who co-authored a new study published in Scientific Reports.
"We're fairly certain that when we look further, and we are, that we'll find there's ground movement even beyond" the four counties, Kim said.
"The ground movement we're seeing is not normal. The ground doesn't typically do this without some cause." —Zhong Lu, Southern Methodist UniversityThe researchers blamed wastewater and carbon dioxide injection that happens during oil drilling, as well as the deterioration of oil wells, for the destabilization of the land.
The research offers "just one more clear sign that we need to get off of oil as fast as possible," Luke Metzger, executive director of Environment Texas, told the Guardian.
The area the researchers examined includes the town of Wink, where two sinkholes have opened in recent decades. The sinkholes are about a mile from each other and disconcerting ground movement has been detected between them.
An area about a half-mile east of one of Wink's sinkhole has sunk at a rate of 15.5 inches per year. Another "subsidence bowl" in the 4,000 square mile area the scientists examined has descended about 40 inches in two and a half years.
"These hazards represent a danger to residents, roads, railroads, levees, dams, and oil and gas pipelines, as well as potential pollution of ground water," geophysicist Zhong Lu said.
There are nearly 300,000 oil wells in the state, according to regulators. More than 47,000 Texans live in the counties included in the study.
"The ground movement we're seeing is not normal. The ground doesn't typically do this without some cause," Lu said.
The scientists are now expanding their study to observe land movement stemming from oil drilling across the Southeast. In 2012, the petrochemical company Texas Brine was blamed for the formation of a toxic sinkhole in Louisiana when a salt cavern it was drilling collapsed, forcing hundreds of residents to evacuate.