Move Over California: Oklahoma Now Leads The Nation For Most Earthquakes

Oklahoma is best known, in the realm of natural disasters, for an abundance of tornadoes. However, it appears the state has a new natural disaster on its hands and it comes in the form of earthquakes. As of December, Oklahoma official outranks California for the most earthquakes in the nation.

The Woodward News reports that earthquakes are happening on a weekly basis in Oklahoma and range in severity. Woodward County Emergency Manager Matt Lehenbauer told the publication that Oklahoma has officially passed up California regarding the prevalence of earthquakes. In fact, earthquakes are becoming part of everyday life for Oklahomans.

EarthquakeTrack shows that today Oklahoma has already experienced eight earthquakes today alone (must be 1.5 magnitude or greater to be counted). Oklahoma has experienced 46 earthquakes in the past seven days, 188 earthquakes in the past month and 1,354 earthquakes in the past year.

Scientists are unsure why Oklahoma has become such an earthquake hotbed. Being in the middle of the United States where warm temperatures meet cold, accounts for the large number of tornadoes and severe weather in the region. However, there is not a consensus by scientists on what is causing the rapid increase in seismic activity in the region.

Many scientists have pointed to the practice of salt water disposal injection as one of the possible causes. NPR reports that “several scientists have suggested that disposal wells, used to dispose of waste from some oil and gas drilling operations — including hydraulic fracturing, or ‘fracking’ — could be the cause of the recent spike.” Seismic activity in Oklahoma seems to align with areas that have active injection sites.

A report issued by the U.S. Geological Survey, headed by Geophysicist William Ellsworth, notes that it is “completely plausible” that salt water injection sites are responsible for the increase in earthquakes throughout Oklahoma. Ellsworth says the earthquakes are “almost certainly manmade” as the region does not have any of the naturally-occurring geographic features that would account for such a large spike in seismic activity.

“A naturally-occurring rate change of this magnitude is unprecedented outside of volcanic settings or in the absence of a main shock, of which there were neither in this region. While the seismicity rate changes described here are almost certainly manmade, it remains to be determined how they are related to either changes in extraction methodologies or the rate of oil and gas production.”

The report gives specific details on the exact activities that could have caused the sudden increase in earthquakes in Oklahoma.

“The modest increase that began in 2001 is due to increased seismicity in the coal bed methane field of the Raton Basin along the Colorado-New Mexico border west of Trinidad, CO. The acceleration in activity that began in 2009 appears to involve a combination of source regions of oil and gas production, including the Guy, Arkansas region, and in central and southern Oklahoma. Horton provided strong evidence linking the Guy, AR activity to deep waste water injection wells.”

Though many scientists agree that the activity is most likely human-induced, others are pointing out that Oklahoma’s fault systems are not as previously thought, noting that many new fault lines that scientists never knew existed have been discovered. The question now remains for Oklahomans, what can be done to curb the increase in earthquakes in the region?

Should more research be done to ensure that fracking, or oil production and waste disposal methods, are not to blame for the increase in earthquake activity? If the activities are responsible for the increase, what steps should be taken?