Author Topic: Earthquake Swarms?  (Read 2165 times)

SAMSON123

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Earthquake Swarms?
« on: February 17, 2011, 05:35:26 PM »
Ark. cities feel unexplained surge in earthquakes



By SARAH EDDINGTON, Associated Press – Thu Feb 17, 9:45 am ET

LITTLE ROCK, Ark. – Jim Sutterfield was briefly puzzled by a thumping sound that seemed to slam the back of his office chair. But when the small-town Arkansas fire chief turned and saw no one was around, he quickly realized it was just an earthquake — again.

"That was only my second time to feel one, but others here have felt them for three or four months now," Greenbrier chief Jim Sutterfield said after feeling the latest tremor on Wednesday. "Now when it happens, people say, 'Well, there's another one.'"

Several small earthquakes ranging in magnitude from 1.8 to 3.8 have rattled the north-central Arkansas cities of Greenbrier and Guy this week, and the cause is unknown.

The U.S. Geological Survey has reported more than 30 earthquakes in the area since Sunday, including a magnitude 3.8 quake Thursday morning and at least 16 others occurring Wednesday, two of which were magnitude 3.2 and 3.5. More than 700 quakes have occurred in the region over the past six months.

Scott Ausbrooks, geohazards supervisor for the Arkansas Geological Survey, said the quakes are part of what is now called the Guy earthquake swarm — a series of mild earthquakes that have been occurring periodically since 2009. A similar swarm occurred in the early 1980s when a series of quakes hit Enola, Ark.

Ausbrooks said geologists are still trying to discover the exact cause of the recent seismic activity but have identified two possibilities.
"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," he said.

A major source of natural gas in Arkansas is the Fayetteville Shale, an organically-rich rock formation in north-central Arkansas. Drillers free up the gas by using hydraulic fracturing or "fracking" — injecting pressurized water to create fractures deep in the ground.

Ausbrooks said geologists don't believe the production wells are the problem, but rather the injection wells that are used to dispose of "frack" water when it can no longer be re-used. The wastewater is pressurized and injected into the ground.

"We see no correlation between natural gas production wells and earthquakes, but we haven't ruled out injection wells," he said, adding that if production wells were the cause, the earthquakes would be scattered all over the region underlain by the Fayetteville Shale formation and not in just one area.

Ausbrooks said the earthquakes are occurring in the vicinity of several injection wells.
Guy Police Chief Dave Martini said the locals continue to blame the gas companies for the quakes.
"We have a disposal well here just outside of the city," Martini said. "People are suspecting that to be causing it, even though there isn't any proof of that."

Martini said the earthquakes started increasing in frequency over the past week and that the disposal well has seen an increase in use recently.

Lawrence Bengal, director of the Arkansas Oil and Gas Commission, said a six-month moratorium was established in January on new injection wells in the area. He said four companies are operating already-drilled injection wells: SEECO Inc., Chesapeake Operating Inc., Clarita Operating LLC and Deep-Six Water Disposal Services LLC.

The moratorium, which is expected to end in July, is intended to allow time to study the relationship — if any — between the injection wells and earthquakes in the area.

The largest quake of the Guy Earthquake Swarm was a magnitude 4.0, which occurred in October, Ausbrooks said. The region could possibly see quakes reaching as high as 5.0, but he said anything above 6.0 is unlikely.

The magnitude scale for earthquakes is logarithmic, meaning a magnitude 3 earthquake would produce waves with amplitudes 10 times greater than a magnitude 2 and 100 times greater than a magnitude 1. Geologists say quakes of magnitude 2.5 to 3.0 are generally the smallest felt by humans.

"These periods of high activity are not uncommon. I don't think it's anything to be overly concerned about," Ausbrooks said. "We always encourage people to keep tuned in to what's going on and to always have an all-hazards disaster preparedness kit."
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SAMSON123

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Re: Earthquake Swarms?
« Reply #1 on: February 17, 2011, 05:40:44 PM »
What the hell is going on?

USGS Watching Mount St. Helen's Volcano Following Earthquake Swarm


Tamara L. Morris – Tue Feb 15, 8:15 pm ET
Contribute content like this. Start here.

The United States Geological Survey is watching the Mount St. Helen's volcano closely after a series of earthquakes struck on Monday. The area around Mount St. Helen's in Washington state has been experiencing minor earthquakes since an initial quake measuring 4.3 in magnitude struck around 10:35 a.m. local time, according to the USGS. Since that first quake, several smaller aftershocks were registered ranging between 1.0 and 2.8 in magnitude.

All of these earthquakes were centered in an area approximately five to six miles north of the Mount St. Helen's crater near the Johnston Ridge Observatory. The quakes were registered at depths between 1.7 and 3.7 miles. In total, at least 12 small earthquakes were registered in the area since the first quake on Monday.

This series of small earthquakes occurring in approximately the same location over a short period of time is known as an earthquake swarm. According to the Global Volcanic Earthquake Swarm Database earthquake swarms are especially common around volcanoes and are often reliable methods of predicting an eruption but the Alaska Volcano Observatory website offered that there may be no need for alarm. The AVO website explained that while earthquake swarms may offer information that a volcano is becoming restless, they are not necessarily indicators of a pending eruption. According to the AVO, "Most seismic swarms are not precursors to eruptions."

The AVO website states that a great deal of seismic data from satellite imagery, deformation, gas measurements and the history of the volcano's geologic past are all taken into consideration when determining an eruption risk.

According to the USGS, seismic activity is common around volcanoes as volcanoes can produce various types of earthquakes--tectonic-type or volcanic-type. Tectonic-type earthquakes around a volcano occur when rocks break along faults or fractures around the volcano. Seismologists must determine if an earthquake near a volcano is tectonic or volcanic as the differences are very subtle.

Earthquakes are different from volcanic tremors, which are vibrations that last longer in duration (lasting from minutes up to days) and are caused by magma movement, movement of pressurized fluids or the escape of pressurized steam or gas.

According to the USGS, the most recent earthquakes are in the same location as another small swarm that happened in late January. In addition, the most recent swarm of quakes is similar to a swarm that began in August 1980. That swarm culminated in a 5.5 magnitude earthquake in February 1981.

The USGS website stated that studies conducted after the 1980 eruption of Mount St. Helen's "suggested that the magma removed during the May 1980 eruption and subsequent lava-dome building caused faults along the seismic zone to slip in response to the magma withdrawal. Similar interaction of volcanic activity and tectonic fault movement is possible in the case of" recent earthquakes,
The USGS also stated that "at present there appears to be no signs of unrest in the volcanic system" and that "The USGS and the Pacific Northwest Seismic Network at University of Washington continue to watch conditions at Mount St. Helens closely."

The current volcano alert level for Mount St. Helen's is still set at normal.

http://news.yahoo.com/s/ac/20110216/sc_ac/7864744_usgs_watching_mount_st_helens_volcano_following_earthquake_swarm_1
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SAMSON123

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Re: Earthquake Swarms?
« Reply #2 on: February 17, 2011, 05:45:29 PM »
Is the world about to shake apart? All of a sudden these earthquake clusters occurring in places around the world



Quake reading on seismograph
A quake reading on a seismograph. Three moderate undersea earthquakes of magnitudes between 5.1 and 5.4 struck off Japan Tuesday and early Wednesday, US seismologists said, but no tsunami warning was immediately issued.
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SAMSON123

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Re: Earthquake Swarms?
« Reply #3 on: February 17, 2011, 05:50:49 PM »
Strong earthquake in southeast Iran

SLIDESHOW
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hazbin

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Re: Earthquake Swarms?
« Reply #4 on: February 19, 2011, 09:31:55 PM »
they are just getting us ready for when they slip the new madrid fault. blaming it on the oil spill. they will submerge a few south western states. i mean it'll be an act of nature.

Jadeveon Clowney

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Re: Earthquake Swarms?
« Reply #5 on: February 19, 2011, 09:42:05 PM »
they are just getting us ready for when they slip the new madrid fault. blaming it on the oil spill. they will submerge a few south western states. i mean it'll be an act of nature.

Who is they?

hazbin

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Re: Earthquake Swarms?
« Reply #6 on: February 19, 2011, 09:45:29 PM »
Who is they?

sorry, i meant the naturally occuring earthquake caused by the new madrid fault slipping will submerge a few states.

Jadeveon Clowney

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Re: Earthquake Swarms?
« Reply #7 on: February 19, 2011, 09:53:25 PM »
sorry, i meant the naturally occuring earthquake caused by the new madrid fault slipping will submerge a few states.

If you don't want to tell, just say so.


When was the last time an earthquake submerged any major landmass?  Atlantis?

hazbin

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Re: Earthquake Swarms?
« Reply #8 on: February 19, 2011, 10:15:11 PM »
If you don't want to tell, just say so.


When was the last time an earthquake submerged any major landmass?  Atlantis?


i was just kidding around. sorry.

SAMSON123

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Re: Earthquake Swarms?
« Reply #9 on: February 20, 2011, 12:29:36 PM »
Who is they?

"THEY" are THOSE who run the show, call the shots and make shit happen....walk lightly in THEIR presence
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SAMSON123

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Re: Earthquake Swarms?
« Reply #10 on: February 20, 2011, 12:40:54 PM »
 
Quote
author=Jadeveon Clowney link=topic=366932.msg5202090#msg5202090 date=1298181205]
If you don't want to tell, just say so.

He won't say anything in order to protect you... because "THEY" may show up at your door late at night unexpectedly and whisk you away never to be seen again.


Quote
When was the last time an earthquake submerged any major landmass?  Atlantis?

Bimini off of the Bahamas
Dwarka off of India
The large lighthouse that once sat in Egypt is now a city completely underwater
In Japan a recently found entire city is completely underwater
Just off Puerto rico and Cuba sits two completely in tact and totally submerged cities..

So to answer your question earthquakes have submerged many a cities.

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