Oklahoma's earthquake surge was natural

Oklahoma's earthquake surge was natural
	FALSE
	"The dramatic increase in earthquakes in Oklahoma after 2009 was a natural phenomenon unrelated to oil and gas production."
Domain	Climate, Energy & Environment
Tactic	Statistical & Evidentiary Distortion; False Context;
Era	Current
First seen	2013
Origin	Statements by the oil and gas industry and, initially, by Oklahoma state officials as earthquake rates rose
Last reviewed	2026-10-27
	Further reading: books on Climate, Energy & Environment

The claim that Oklahoma's earthquake surge was natural was widely repeated in the early 2010s, as a state that had historically experienced few felt earthquakes suddenly began experiencing hundreds a year. Scientists from the US Geological Survey and elsewhere established that the surge was caused by the injection of large volumes of wastewater produced during oil and gas extraction deep underground, which increased pressure on faults. In 2015 the Oklahoma Geological Survey acknowledged that most of the earthquakes were very likely triggered by wastewater injection. After regulators ordered injection volumes reduced, the number of earthquakes fell sharply.

The claim

As earthquakes increased, industry representatives and some officials suggested that the activity might be part of a natural cycle or that the evidence linking it to oil and gas operations was inconclusive. The question was politically and economically sensitive in a state where the oil and gas industry is a major employer and source of revenue.

Origin

Before 2009 Oklahoma averaged about one or two earthquakes of magnitude 3.0 or greater per year. As oil production expanded, particularly from formations that produce large amounts of salty water alongside oil, companies disposed of this wastewater by injecting it into deep rock layers, especially the Arbuckle formation. The number of magnitude 3.0 or greater earthquakes rose to hundreds per year, peaking at more than 900 in 2015, more than in California. In November 2011 a magnitude 5.6 earthquake struck near Prague, Oklahoma, damaging homes. In September 2016 a magnitude 5.8 earthquake near Pawnee became the strongest in the state's recorded history.

What the evidence shows

Timing and location. The increase in earthquakes coincided with the rise in wastewater injection, and earthquakes clustered near high-volume disposal wells.
Mechanism. Injecting fluid raises pressure within rock, which can reduce the friction holding faults in place and allow them to slip. This mechanism has been understood since the 1960s, when wastewater injection at the Rocky Mountain Arsenal near Denver triggered earthquakes.
Scientific studies. Studies published in journals such as Science and by the US Geological Survey linked the earthquakes to injection. In April 2015 the Oklahoma Geological Survey stated that the majority of recent earthquakes were very likely triggered by the injection of produced water in disposal wells.
Wastewater, not fracking itself. Hydraulic fracturing, or fracking, the process of fracturing rock to release oil and gas, causes only small and infrequent earthquakes directly. In Oklahoma the main cause was the disposal of large volumes of wastewater, much of it produced by conventional and unconventional oil production.
Reduction followed regulation. Beginning in 2015, the Oklahoma Corporation Commission directed operators to reduce injection volumes in affected areas. Earthquake rates declined substantially in following years, consistent with the scientific explanation.

Reporting by EnergyWire and Bloomberg in 2015 indicated that state scientists had faced pressure from industry figures during the period when officials were reluctant to acknowledge the link.

Why it persists

The claim that the earthquakes were natural persisted for several years because of economic stakes, scientific caution about attributing individual earthquakes and the political influence of the industry. Natural earthquakes do occur in Oklahoma, which made it possible to suggest that the increase might be natural. The case illustrates how scientific findings that threaten powerful interests can be delayed.

Lessons for readers

A dramatic change from a long-term baseline usually has a cause worth investigating.
Look for consistent timing, location and mechanism when assessing a link.
Distinguish between related activities, such as fracking and wastewater disposal.
Notice when economic interests may be influencing official statements.
When an intervention reduces a problem as predicted, it strengthens the evidence for the cause.

Sources

K. M. Keranen et al., "Sharp increase in central Oklahoma seismicity since 2008 induced by massive wastewater injection," Science 345, no. 6195 (2014).
Oklahoma Geological Survey, "Statement on Oklahoma Seismicity," April 21, 2015.
US Geological Survey, "Induced Earthquakes" program materials and Oklahoma earthquake data.
Mike Soraghan, reporting on Oklahoma earthquakes and state seismologists, EnergyWire, 2015.