I am bemused to see that there is a moderate earthquake in Oklahoma making the news.

Such things are not unknown, of course, but the “Green” oriented blogs are all blaming the earthquake on “fracking”.

This is a “hot” item, since the oil shales of North Dakota and Pennsylvania are potential “black gold” that will rewrite the balance of oil from the Middle East (although most US oil is actually from either the US or other western hemisphere areas, mainly Canada).

I wasn’t aware that “fracking” was being done in Oklahoma, but they do “inject” wells, and it is well known that you can cause earthquakes by taking out oil if you don’t pump water back into the hole.

So if the Oklahoma earthquakes were caused by bad oil pumping, there is an argument to clarify the problem and fix it.

Yes, I said “Fix it”.

The environmentalists might want to stop pumping all oil, but my Oklahoma neighbors were delighted when the price of oil went up and they restarted pumping in our area. Many were working in low wage jobs, or were working on oil rigs or in countries such as Venezuela and Nigeria that had started becoming a bit dangerous. More local jobs were both needed and welcome. The attitude was:  environmental problems? You can’t eat the environment.

Even health problems thought to be due to the wells were shrugged off as the price of having a job. True, most folks do want a cleanup of environmental damage from the past, but they also want and need jobs.

But the real question is: can the earthquakes be blamed on something simple, like improper oil extraction, (which could be “fixed” with another techological fix) or is there a fault line or other cause that scientists can’t find?

Missing a fault line that could blow at any time would actually be more of a worry. Most homes and buildings in much of the central US are not “earthquake proof” even though the New Madrid fault near St. Louis was the largest earthquake in US recorded history.

Heck, most of them are not even “tornado proof”, even though folks live in “Tornado alley”.

For those who are not familiar with the landscape, Here is a list of earthquakes in Oklahoma since Dec 1897.

Due to oil?

The first oil well in Oklahoma was in April 1897…but the Oklahoma Geological survey states:

The earliest documented earthquake in Oklahoma occurred on October 22, 1882, and while it cannot be precisely located, the strongest shaking, Modified Mercalli Intensity of VIII, was reported at Fort Gibson, Indian Territory.  On April 9, 1952 the largest instrumentally recorded earthquake in Oklahoma occurred near El Reno in Canadian County.  This earthquake had a magnitude of 5.5 and caused damage to the State Capitol Office Building in Oklahoma City.  Its effects were felt as far away  as Austin, Texas and Des Moines, Iowa.

So earthquakes were there before the oil wells.

And most of the earthquakes are in central Oklahoma, where they do pump oil, but a bit west of the Tulsa oil fields which have suffered few reported earthquakes.

map: http://geo.ou.edu/MapsFrame.htm

So what does the Oklahoma Geological survey say about the earthquake cause?

Generally away from plate boundary settings, such as Oklahoma, earthquakes will be smaller with magnitudes generally less than 6.5.  Small earthquakes (magnitudes 5 or less) occur nearly everywhere in the world.  These types of earthquakes can cause damage and loss of life, but damage is usually moderate and closely concentrated around the epicenter, where the earthquake occurred.  Oklahoma earthquakes generally occur at shallow depths ranging from about 5 to 15 kilometers (3-10 miles) depth.

In other words, except for a faultline in SW Oklahoma that last slipped 1200 years ago, things should stay about the same.

But one does wish for a good geological explanation, and if the opening of the oil wells correlates with the recent earthquakes.

E&E News examines the problem and finds no easy answer.

A previously unreported study out of the Oklahoma Geological Survey has found that hydraulic fracturing may have triggered a swarm of small earthquakes earlier this year in Oklahoma. The quakes, which struck on Jan. 18 in a rural area near Elmore City, peaked at magnitude 2.8 and caused no deaths or property damage…The majority of the microquakes struck within 3.5 kilometers of the fracturing well, Picket Unit B 4-18. The quakes were shallow and fit well in time and space with the start of fracturing in the nearby well. The geophysical model fit, too…

The fracturing continued at the Picket well after the earthquakes, and the survey detected no additional seismic activity during that time, Holland said. The well was located in a geologically complex region riven by thrust rocks, he added, and a quake would likely have occurred at some point with or without the drilling — the rocks were primed for it.

“These earthquakes were likely to happen,” he said.

So the answer is: yes, no, and maybe. Or maybe “all of the above”.
Jumping to conclusions based on one’s ideological background (it was the fracking or from hydrolic injection of water, or that it was ordinary earthquakes and that the green lobby is again lying about the risk) without good geological knowledge only clouds the issue.


Nancy Reyes is a retired physician living in the Philippines. She practiced medicine for several years in Oklahoma.

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