Large Earthquake Linked Again To Wastewater Injection

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The evidence is mounting that the dramatic surge in earthquakes here in Oklahoma can be related to oil and gas drilling activities, but will state leaders do anything about it?

On Thursday, the U.S. Geological Survey (USGS) issued a media release citing its study that a 5.7 magnitude earthquake that struck near Prague in November, 2011 “was the largest human-caused earthquake associated with wastewater injection.”

The coauthor of the study, Elizabeth Cochran, a USGS seismologist, pointed to an earlier earthquake of 5.0 magnitude the day before that may have led to the larger earthquake. The initial earthquake may have been caused by wastewater injection. Cochran said, “"The observation that a human-induced earthquake can trigger a cascade of earthquakes, including a larger one, has important implications for reducing the seismic risk from wastewater injection.”

In oil and gas drilling processes, including hydraulic fracturing or “fracking,” massive amounts of wastewater are injected by high pressure into underground rock formations. These sites are called wastewater injection wells. Some scientists believe this process can destabilize underground surfaces and trigger earthquakes along the state’s fault lines.

Last year, Scientists from the University of Oklahoma and Columbia University also argued that the 5.7 magnitude earthquake could be related to wastewater injection wells. That earthquake, the largest ever recorded in Oklahoma, damaged several homes.

In recent years, there have been literally hundreds of earthquakes, mostly small, in Oklahoma. Some residents here have been worried that the smaller earthquakes could be a prelude to a major temblor that might cause massive damage and take lives.

There are new regulations for more thorough inspections of injections wells under consideration by the Oklahoma Corporation Commission, but they apparently have to be approved by the legislature and governor.

The questions are whether the new inspections go far enough to ensure the safety of Oklahoma residents and whether the Republican-dominated government here will take any action that might be opposed by the powerful oil and gas political lobby.

As I’ve argued before, this is an important safety and economic issue in Oklahoma, one that has the potential to severely impact lives and future development. Who wants to live or build a home in an area that experiences hundreds of earthquakes each year?

The oil and gas industry, which is experiencing a mini-boom in the state and other areas of the country, is certainly important to Oklahoma, but at some point earthquake risk factors and other environmental factors related to fracking outweigh its overall economic impact.

Meanwhile, it’s vitally important that the USGS and scientists continue to study the surge in earthquakes here over the last two or three years. It could literally be a matter of life and death.