As Quakes Rattle Oklahoma, Fingers Point to Oil and Gas Industry

nytimes.com ^ | 4/3/2015 | RICHARD A. OPPEL Jr. and MICHAEL WINES

[dirtboy]

I realize that, but there has been a significant increase in recent years.

[thackney]

Yes, a worldwide increase in earthquake activity.

[dirtboy]

A tenfold worldwide increase? And that is being an order magnitude generous, Oklahoma has seen a hundredfold increase over the last decade.

[thackney]

The increase isn't even in all location.

And the earthquake increase in Oklahoma in the 1950s?

This isn't the first time earth quakes in the general area greatly increased then greatly decreased.

But this time, it must be oil production's fault.

Right.

http://earthquake.usgs.gov/earthquakes/states/oklahoma/history.php

This year is a statistical anomaly. But we've got catalogs all the way back to 1897 and there's basically been earthquakes in all but three counties in Oklahoma. We don't know for certain what triggers peak years. Could just be random chance, the statistics playing out. One thing, that's somewhat applicable here ... if you look at the North Anatolian Fault in Turkey, what they can show is that each rupture adds stress to another section of the fault, which then ruptures, and it just unzips as it goes along. The same thing can happen here. But there's no direct timing. It can be years before the next section goes ahead and ruptures. Anywhere between 10 and 20 years between sections on the Anatolian fault.

http://boingboing.net/2010/10/14/earthquakes-in-oklah.html

This is not an area of concentrated hydraulic fracturing or waste water disposal. Areas that have far more of both don't have this occurrence.

[dirtboy]

There are a lot of existing old faults in the areas with earthquakes. IMO the increased injection rates are re-activating them. As far as the increase in the 1950s, we only have anecdotal analysis since there were not instruments in place like they are now so we have no idea how similar that was to this event. And earthquakes have been increasing steadily since 2010. I just do not see how an increase of two orders of magnitude can be downplayed here.

[Rebelbase]

[thackney]

Because increase of this magnitude happened before disposal wells and in locations without disposal wells.

And in areas with more faults and more disposal wells have no earthquake changes.

But this location must be caused by disposal wells?

[dirtboy]

Because increase of this magnitude happened before disposal wells and in locations without disposal wells.

Examples? And not on plate margins, either, but mid-continental areas with old fault zones.

[thackney]

Go back to post #40.

[thackney]

Brown points to similar seismic activity in Oklahoma in the 1950s. Other than the 5.6 quake in Prague in 2011, the largest quake on record in Oklahoma is a 5.5 in El Reno in 1952. Brown says that quake was one of many in the ‘50s, just like the Prague quake is one of many in the last few years.

Brown is quick to point out back in the 1950s, there were no wastewater injection wells in Oklahoma to cause quakes. He also contends the quakes in Oklahoma today are deeper in the earth than injection wells can reach.

Separating his hands, Brown told the crowd, “You’re injecting up here and the earthquakes are down here, let’s talk about something that’s possible.

http://www.koco.com/news/geologist-worldwide-seismic-uptick-responsible-for-oklahoma-earthquake-swarm/27118772

[thackney]

A sequence of powerful earthquakes struck the mid-Mississippi River Valley, central United States, in the winter of 1811-1812. The two largest probably exceeded the size of any continental western US earthquake. No fewer than 18 of these events were felt on the Atlantic seaboard or in Washington, DC (Nuttli 1987), at least 1000 km east, which implies moment magnitude M » 6.0-6.5 (Table 1).

Over time, this earthquake series has taken the name of the small riverboat town New Madrid, which lay at the heart of the epicentral zone and which in 1811 was the largest settlement on the river between St. Louis and Natchez. The name has proven apt, for New Madrid by happenstance marks the intersection of three of the six fault segments currently illuminated by microseismicity and believed to be rupture planes of the principal 1811-1812 earthquakes.

http://www.memphis.edu/ceri/compendium/enigma.pdf

[dirtboy]

I am well aware of New Madrid. I would like to see recent history of that region for comparison.

[thackney]

Update: 10:35 a.m. At least five more earthquakes have struck Thursday morning in that remote area of northwestern Nevada that has been the scene of a continuing earthquake cluster. The largest was magnitude 3.1 shortly before 9:30 a.m. On Wednesday, a magnitude 4.1 hit the area, with more than 50 of magnitude 3 or greater hitting in the last week, according to the Nevada Seismological Laboratory at University of Nevada, Reno. Earthquake activity over the last week is more than in previous months combined, scientists said.

Update: 10:25 a.m: The earthquake cluster occurring in northwest Nevada near the Oregon line is continuing, with 10 more quakes occurring so far on Wednesday. Four of the quakes were at magnitude 3 or above, with the largest measured at 4.1.

http://www.rgj.com/story/news/2014/11/11/scientists-nevada-earthquake-cluster-biggest-decade/18889345/

Kent noted that for the last 60 years or so, Nevada – one of the nation's three most seismically active states – has been relatively quiet when it comes to earthquakes. Other periods farther back in history have produced more quakes, some of them strong, including in the Reno area.

- - - - - -

The point here, earthquakes are not a steady occurrence in many places.

[thackney]

I am well aware of New Madrid. I would like to see recent history of that region for comparison.

Are you questioning if the earthquakse in that area are consistently happening over the decades? I am not sure what information you are seeking.

[dirtboy]

Nevada is not a good comparison, it is in the Basin and Range which is undergoing crustal expansion.

[dirtboy]

He also contends the quakes in Oklahoma today are deeper in the earth than injection wells can reach. Separating his hands, Brown told the crowd, “You’re injecting up here and the earthquakes are down here, let’s talk about something that’s possible.

That is a bunch of hooey, which calls into question his overall veracity. In researching injection wells in Oklahoma, they can go down to the Arbuckle, which is just above basement.

[thackney]

How about Oklahoma? Do you consider Oklahoma a good comparison for Oklahoma?

1950s great increase in number and strength of earthquakes and then the fall back down to the level before this decade?

[thackney]

Recent ‘Swarm’ Of Earthquakes Not Entirely Uncommon In New England
http://www.courant.com/community/plainfield/hc-why-are-plainfield-earthquakes-happening-0114-20150113-story.html

Unfortunately, there is no answer for why earthquakes happen when they happen, Ebel said. Even in major earthquake zones there is no way to determine when a quake will occur. More earthquakes have been reported in recent years in some areas with new oil and gas exploration, according to the U.S. Geological Survey. But New England’s earthquakes are naturally occurring.

Earthquakes in Connecticut, while they may seem rare, are not exactly uncommon, Ebel said.

“What we have now is what I would characterize as a swarm of small earthquakes,” he said. “We see that on occasion here in the Northeast.”

The last time a series of earthquakes struck Connecticut was in the 1980s, Ebel said, when several earthquake swarms rattled the Moodus area for weeks. In fact, the name Moodus comes from the Native American term “Morehemoodus,” or place of noises, because of the earthquake rumblings that have apparently occurred in the area for hundreds of years, according to the USGS.

[dirtboy]

We have no way to accurately compare Oklahoma 1950s earthquakes to today, just largely anecdotal evidence.

[dirtboy]

Interesting article:

http://www.tulsaworld.com/news/local/state-orders-injection-well-shut-down-after-northwestern-oklahoma-earthquake/article_4184d155-d9b2-523d-a8d5-033174ff8584.html