Earthquake Swarm Hits Central Oklahoma


‘Swarms’ usually occur during a period of a few days, not over eight months, geologist says


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December 20, 2009
By Johnny Johnson and Matt Dinger
The Oklahoman

JONES — During a typical year, Jones residents will feel one or two earthquakes. This year there have been 25 since March, and all of them have been felt, according to the Oklahoma Geological Survey.

"I can tell you what’s going on, but we don’t know why,” engineering geologist Ken Luza said. But Luza said equipment coming to the state next year might help answer some questions.

Luza said he’s not aware of any faults near Jones, but there are thousands of unnamed faults buried deep throughout the state’s subsurface.

"Now, we usually average about 50 earthquakes per year in Oklahoma,” Luza said. "So it’s not unusual to have earthquakes. But what seems unusual is that they seem to be concentrated in eastern Oklahoma County.”

Paul Wallis of Jones describes the earthquakes as "the boom and the shake.”

Wallis said Thursday night’s earthquake and the one early Dec. 13 were the ones his family has felt most strongly.

"That one last night ... we were actually putting the Christmas tree up, and the top went to shaking,” he said.

And on the morning of Dec. 13, Wallis said, he was in bed when the boom startled him awake about 2:30 a.m.

"I think the boom woke me up, and I was sitting up when the shaking was taking place. We’ve got the train track that runs about 50 yards from the house, and it was about two or three times louder than that,” he said.

His wife was downstairs working on the computer and ran upstairs.

"Her and the girls went to squealing,” Wallis said.

The family is not able to get earthquake insurance through their provider, but Wallis said he’d already looked into it.

He said the low premiums would be worth the added protection.

"We’re kind of right in the middle of it, it seems like,” Wallis said.

Wallis said some of his friends who live outside of town have felt some of the other tremblors but were unaffected by the two that have shaken his own house the hardest.

When a rash of earthquakes happen in one location over an extended time, Luza said, it’s called an earthquake swarm.

But swarms usually occur during a period of a few days to a week.

"It’s unusual to see it last eight months,” he said.

Luza said there are only 15 seismograph stations in the state.

That’s enough to narrow down the location of the epicenter to about a six-mile radius.

But it’s not enough to get an exact location of the quake or depth, or to be able to tell whether the ground there was moving up and down, side to side or both, he said.

"To measure that, we’d need more seismograph stations, and they are coming,” Luza said.

Beginning next year, Project Earth Scope, which is funded by the National Science Foundation, will bring in an additional 25 seismograph stations to Oklahoma. That will give the state a total of 40 stations, Luza said.

The equipment will be housed in Oklahoma for a two- to three-year study period then moved to another state.

But during that short window, Luza said, researchers will be able to collect data they have never had access to.

"We’re hoping this will give us the opportunity to look at the data and maybe we’ll be able to say something more definitive as to why,” he said.


Events

DATE TIME (UTC) COUNTY MAGNITUDES LAT. LONG. DEPTH
2009 MAR 08 13:06:39 UTC OKLAHOMA MAG. 3.6 35.452N 97.479W 5.00
2009 MAR 17 17:24:52 UTC OKLAHOMA MAG. 2.7 35.446N 97.456W 5.00
2009 MAR 17 17:41:37 UTC OKLAHOMA MAG. 2.5 35.446N 97.456W 5.00
2009 MAR 17 19:57:15 UTC OKLAHOMA MAG. 2.4 35.446N 97.456W 5.00
2009 MAY 29 01:26:28 UTC LINCOLN MAG. 2.2 35.80N 97.00W 5.00
2009 JUN 14 21:31:08 UTC LINCOLN MAG. 3.4 35.62N 96.85W 5.00
2009 JUN 16 16:32:46 UTC LINCOLN MAG. 2.8 35.89N 96.87W 5.00
2009 JUN 26 21:23:14 UTC GARFIELD MAG. 3.6 36.33N 97.46W 5.00
2009 JUL 01 17:14:48 UTC POTTAWATOMIE MAG. 3.4 35.40N 97.08W 5.00
2009 JUL 17 17:40:50 UTC MCCLAIN MAG. 2.2 34.99N 97.35W 5.00
2009 JUL 22 02:25:59 UTC LINCOLN MAG. 3.3 35.76N 96.97W 5.00
2009 AUG 14 20:08:59 UTC OKLAHOMA MAG. 2.3 35.46N 97.41W 5.00
2009 AUG 27 08:22:15 UTC SEMINOLE MAG. 3.4 34.99N 96.59W 5.00
2009 AUG 27 12:58:56 UTC OKLAHOMA MAG. 2.5 35.56N 97.29W 5.00
2009 AUG 27 15:17:52 UTC OKLAHOMA MAG. 2.7 35.56N 97.29W 5.00
2009 AUG 27 15:31:54 UTC OKLAHOMA MAG. 2.5 35.56N 97.29W 5.00
2009 AUG 27 17:14:22 UTC OKLAHOMA MAG. 2.6 35.56N 97.29W 5.00
2009 AUG 27 18:32:35 UTC OKLAHOMA MAG. 2.7 35.56N 97.29W 5.00
2009 AUG 28 02:09:12 UTC OKLAHOMA MAG. 3.7 35.56N 97.29W 5.00
2009 AUG 28 03:30:55 UTC OKLAHOMA MAG. 2.4 35.56N 97.29W 5.00
2009 AUG 28 04:15:50 UTC OKLAHOMA MAG. 2.3 35.56N 97.29W 5.00
2009 SEP 08 14:03:12 UTC OKLAHOMA MAG. 2.3 35.63N 97.20W 5.00
2009 OCT 23 03:56:29 UTC LINCOLN MAG. 3.0 35.79N 97.01W 5.00
2009 OCT 23 03:58:11 UTC LINCOLN MAG. 2.5 35.79N 97.01W 5.00
2009 NOV 02 18:27:05 UTC OKFUSKEE MAG. 2.7 35.43N 96.55W 5.00
2009 NOV 14 11:13:01 UTC OKLAHOMA MAG. 3.0 35.52N 97.21W 5.00
2009 NOV 16 11:12:59 UTC OKLAHOMA MAG. 2.5 35.49N 97.23W 5.00
2009 NOV 17 04:00:17 UTC STEPHENS MAG. 3.0 34.52N 97.62W 5.00
2009 NOV 23 05:47:12 UTC OKLAHOMA MAG. 2.6 35.49N 97.23W 5.00
2009 NOV 25 16:51:39 UTC OKLAHOMA MAG. 2.1 35.52N 97.27W 5.00
2009 NOV 29 01:36:58 UTC OKLAHOMA MAG. 3.1 35.60N 97.27W 5.00
2009 DEC 07 17:44:25 UTC OKLAHOMA MAG. 3.5 35.55N 97.25W 5.00
2009 DEC 11 14:00:42 UTC OKLAHOMA MAG. 2.8 35.58N 97.32W 5.00
2009 DEC 12 11:34:05 UTC OKLAHOMA MAG. 3.1 35.53N 97.33W 5.00
2009 DEC 13 08:38:25 UTC OKLAHOMA MAG. 3.4 35.59N 97.29W 5.00
2009 DEC 15 15:39:15 UTC OKLAHOMA MAG. 2.4 35.57N 97.28W 5.00
2009 DEC 17 23:52:01 UTC OKLAHOMA MAG. 2.2 35.56N 97.28W 5.00
2009 DEC 18 02:25:39 UTC OKLAHOMA MAG. 2.8 35.54N 97.27W 5.00

http://newsok.com/quakes-still-shaking-jones/article/3426115