Scientists Say Oil Industry Likely Caused Largest Oklahoma Earthquake
The injection of wastewater from oil and gas production deep into the ground has been known to cause quakes within months, but the 2011 temblor in Oklahoma occurred after nearly two decades.
Advanced methods of oil and gas drilling create massive amounts of toxic wastewater. For example, hydraulic fracturing, also known as fracking, uses high-pressure water to unlock natural gas from shale formations. Drillers also use water to force oil from wells that cannot be captured through traditional methods, part of a practice known as "enhanced oil recovery." (See related interactive: "Breaking Fuel from the Rock.")
The use of such methods has exploded in the United States in recent years, contributing to the domestic boom in shale gas and oil production. Much of the wastewater that emerges as a byproduct is pumped into wells beneath the earth's surface for disposal.
Although the controversial practice of fracking has been directly linked to at least
