New faultline discovered is longer than expected! Arkansas earthquakes could be big!!!

Arkansas Democrat Gazette reports that "Geologists say a previously unmapped fault that is the source of a swarm of earthquakes around Guy and Greenbrier in Faulkner County is longer and potentially more destructive than they initially believed."Scott Ausbrooks from the Arkansas Geological Survey revealed the discovery of a new faultline in the Guy/Greenbrier area this week.  The revelation does not surprise local residents, however Ausbrooks says it is longer than they originally thought and could produce earthquakes of greater power.  The original hypothesis was that the faultline was 3.5 miles long, but it now appears to be 6-7.5 miles long. 

Scientists as recently as January thought that what they’re informally calling the “Guy-Greenbrier Fault” spanned 3.7 miles, but now estimate it to be 6 to 7.5 miles long.
Ausbrooks said the length is a concern because a longer fault could trigger bigger earthquakes.
Theoretically, if an entire 3.7-mile fault were to rupture, it could trigger a magnitude-5.0 to magnitude-5.5 earthquake. A 6-mile fault, meanwhile, could trigger a magnitude-5.5 to magnitude-6.0 quake.Ausbrooks said a magnitude-6.0 quake releases 32 times more energy than a magnitude-5.0 quake.In general, poorly built structures begin to sustain structural damage with magnitude-5.5 quakes, Ausbrooks said. Structures at the epicenter of such a quake would have broken windows and cracked masonry, he said, and the quake would be felt outside the state.

A magnitude-4.7 quake struck Feb. 27 roughly three miles from Greenbrier, and was Arkansas’ largest earthquake in about 35 years. It was one of hundreds that have been felt in the area since September.

Scientists, including those at the state geological survey and at the Center for Earthquake Research and Information at the University of Memphis, discovered the Guy-Greenbrier Fault by tracking the pattern of recent seismic activity in the area. The scientists then confirmed the fault’s existence by using imaging of the subsurface obtained from companies operating in the shale. The companies hadn’t noticed the fault because “it’s much deeper than what they are concerned about,” Ausbrooks said. The center says on its website that they are concerned there is a risk of triggering more and larger earthquakes if the injection wells continue to operate.

The potential power of an earthquake along this fault could reach up to 6.0 on the Richter Scale and could cause significant damage at the epicenter. Why are we experimenting with fracking and injection wells? The truth is the chemicals used in fracking are designed to prop open the rock. The industry calls it "slickwater fracking." They lubricate and make "slippery" the formations and cause mini explosions in the strata when they frack. Then the gas companies need to get rid of the millions of gallons of toxic wastewater so they inject that back into the strata at high pressure. Why are they risking lives in such a seismically sensitive area? Could the faultline actually be longer than 7.5 miles? We have friends in Mountain View who feel earthquakes from Greenbrier/Guy even if they are below 3.0 on the Richter Scale? It would probably take more money and research to discover this information, but why experiment with human lives in the meantime. 


The Arkansas Oil and Gas Commission weighs in on the issue of the two injection wells on March 29th.  Ausbrooks discussed the two injection wells:
 

“The theory is that the well increases the ... pressure in the rock formation sufficiently to overcome friction, to allow the fault to move, which generates the earthquake,” Ausbrooks said. Ausbrooks said the fault is deep and old. Its last vertical movements are believed tohave been 400 million years ago, he said. The fault doesn’t cut to the surface, and the uppermost part is about 8,000 to 10,000 feet deep. Clarita’s well is 7,800 to 10,900 feet deep while Chesapeake’s is 5,700 to 6,200.  The Clarita well is “injecting at the same layer of rock” that the fault cuts up into, Ausbrooks said. Operators of the well are arguing that the earthquakes are occurring because of natural causes. Clarita said in a release last week that the quakes began before its well was operational. The general area - northern Faulkner County - has seen natural seismic activity in the past, including a series of small quakes that began in 1982 in Enola, which is about 10 miles away from the current swarm. However, the Enola earthquakes originated from a different fault than the current swarm, Ausbrooks said.  Ausbrooks said there were “no known earthquakes in this Guy-Greenbrier swarm area” before the first of the two wells went into operation.

Since the injections stopped Thursday, “we’re still seeing micro-seismicity,” Ausbrooks said. He added that Arkansas saw a “couple of” magnitude-1 and magnitude-2 quakes on Tuesday. “There’s no reason why that shouldn’t continue for a period of time.”  Scientists at the center in Memphis and with the survey are basing their research on a 1960s case in Denver that showed injection wells could cause earthquakes. Ausbrooks said that the quakes diminished dramatically after the injections were stopped and started once the injections began again. However, the largest quakes struck about two years after the injections stopped, he said.
“Once you start that pressure front moving out [through the rock], it takes time for it to dissipate and to move out.”
Ausbrooks said he couldn’t comment on what the survey’s position is on a potential link between the wells and the seismic activity because it is awaiting the March 29 hearing.

Please come out to the AOGC meeting on March 29th.  We must make a statement to the commissioners and our government.   Any reasonable person would agree that we must err on the side of caution. 






Read the Arkansas Democrat Gazette article here.

Arkansas Earthquakes: We are calling for people to keep an earthquake journal!

We have received emails and calls from people who are concerned.  One person said:  "i cant believe they want to risk greers ferry we could be seriously doomed .we are a rocking rolling here man 23 since midnite and so far only 4 on usgs website and one downgraded from 3.0 to 2.7 are we manipulating the data now?" OMG.

Just a suggestion.  We have received reports from people who describe their earthquake experiences as more severe than the final USGS "report" of the Richter Scale reading.  The USGS is allowed to adjust the reading up or down, based on field input.  Please give them information about what you are experiencing here and also keep your own written journal.  Include time, date and a narrative about the experience and any damage.   The scale below could be a useful reference.

The Richter Scale. A very important fact in this scale is that as each number goes up, the earthquake increases *10 times* in power

1. Felt by instruments only

2. Felt by sensitive people and sensitive animals (10 times #1)

3. Felt by many people--feels like a passing truck (100 times #1)

4. Felt by everyone; pictures fall off the wall (1,000 times #1)

5. Damage--may cause weak walls to crack and fall (10,000 times #1)

6. A destuctive earthquake in populated areas; falling smokestacks, etc. (100,000 times #1)

7. A major earthquake causing serious damage (1,000,000 times #1)

8. A disaster--a great earthquake that produces total destruction to nearby communities {1906 in San Francisco--8.3} (10,000,000 times #1)

9. Libson, Portugal had the highest ever in 1775 at 8.9. (100,000,000 times #1)

An interesting article about the New Madrid Seismic Zone is here.

Arkansas Earthquakes in Greenbrier Increase as Natural Gas Drilling and Fracking Increase!!!

People in the Greenbrier area are certain of one thing: as the drilling and fracking increased in their area so did the earthquakes.  Greenbrier resident, Dirk Deturck lives on a ridge between Guy and Greenbrier.  He was watching the rigs.  As soon as they increased drilling and fracking on the Greenbrier side, then the Greenbrier quakes started increasing in intensity and frequency.  "They feel really different now." Deturck said.  He described the sensation as waves rolling underneath them and when it hit it sounds like a "boom."  He believes the injection wells have a lot to do with the quakes, but blames all of the activity including fracking and compressor stations.  During the snow storm Deturk noticed all gas activity stopped: no compressors running, no drilling, no fracking and no injecting.  Guess what?  He said he looked at USGS data and there were no earthquakes for three days following the snow.  He also noticed a cluster of small quakes on the Tennessee side of the Mississippi River the same day as some larger ones in Greenbrier.  He feared the gas production could trigger a "big one" and possibly set off the New Madrid Fault.  We've had many assurances from experts from AGS that that will PROBABLY never happen, but still they tell us to make plans for emergency preparedness.  Interesting.

Arkansas Earthquakes...Guy, Greenbrier...Many Suspect Fracking and Injection Wells. Will They Trigger the Big One?

The world has been watching.  Everyone knows earthquakes happen, but they think of California, or the Ring of Fire.  No one would imagine the once sleepy town of Guy, Arkansas as the center of an earthquake storm. We have experienced over 700 earthquakes in the space of six months.  Seismologists have labeled this an official swarm and have peddled the idea that this is a seismically sensitive area and that no one should be alarmed.  Well, that's not going over very well with the populace.  People have been rocked while sitting on their commodes, cabinets have fallen off the walls, cracks have been appearing in foundations and some framing.  People are frightened.  Geologist Scott Ausbrooks from the Arkansas Geological Survey has said he ruled out fracking and is studying injection wells as the possible culprit.  Meanwhile, people in the area agree with him regarding the injection wells, but still think the whole process of fracking is contributing to this.  Mr. Ausbrooks is quoted in Planetsave: "It could just be a naturally occurring swarm like the Enola swarm, or it could be related to ongoing natural gas exploration in the area,” Scott Ausbrooks, geohazards supervisor for the Arkansas Geological Survey, said.

The earthquakes in the past week have been increasing in number and intensity some over 4.0 on the Richter Scale.  They have been centered a little south of Guy, in Greenbrier and have also been felt by people in the larger town of Conway, AR.  Why doesn't Governor Beebe call for a real moratorium on injection wells so we can see if the hypothesis is correct?  If earthquakes are caused by injection wells, we should stop injecting immediately.  Why not stop for a month?  We could see if the quakes stop.  Right now, many, many, many people believe our government is courting a huge disaster.  What if they trigger "the big one?"  Even Mr. Ausbrooks warns people to have emergency preparedness measures in place.  WHY, if there is no danger?  Read the entire Planetsave article here.