[T]he agencies reported that 183 earthquakes of magnitude 3.0 or greater occurred in Oklahoma from October 2013 through April 14, 2014. This compares with a long-term average from 1978 to 2008 of only two magnitude 3.0 or larger earthquakes per year. As a result of the increased number of small and moderate shocks, the likelihood of future, damaging earthquakes has increased for central and north-central Oklahoma. [...]More large earthquakes than Oklahoma has experienced in the past have been traced since 2009. In 2011, the epicenter of the second-largest Oklahoma quake in recorded history—5.6—occurred near Prague, a town of about 2,200.
The joint statement indicates that a likely contributing factor to the increase in earthquakes is wastewater disposal by injection into deep geologic formations. The water injection can increase underground pressures, lubricate faults and cause earthquakes – a process known as injection-induced seismicity. Much of this wastewater is a byproduct of oil and gas production and is routinely disposed of by injection into wells specifically designed and approved for this purpose. The recent earthquake rate changes are not due to typical, random fluctuations in natural seismicity rates.
Like just about every criticism of the oil and gas industry, the very idea of quakes being caused by fracking or wastewater injection related to it has been widely ridiculed by flacks and shills. Less than five years ago, nearly anybody who even suggested it got laughed out of the room. It's getting new attention now. As well it should given that there are, according to a tally by the Environmental Protection Agency, 144,000 injection wells throughout the nation. At the annual meeting of the Seismological Society of America last week, after an all-day session looking at research into "Induced Seismicity," scientists called for more investigation into connections between fracking wastewater disposal and earthquakes.
Naturally, inevitably, industry sees things differently. The Associated Press quotes Brian Woodward, the vice president of regulatory affairs for the Oklahoma Independent Petroleum Association:
Granted, we’ve not seen this level of seismic activity in Oklahoma in the last 60 to 80 years and before that we don’t have a record. It causes us all concern, but the rush to correlate this activity with our industry is something we don’t believe is necessarily fair.And when the big earthquake hits, the OIPA will no doubt trundle someone out to say "nobody could have predicted."