Latest US Earthquakes Updated - USGS

	MAG	UTC DATE-TIME y/m/d h:m:s	LAT deg	LON deg	DEPTH km	LOCATION
MAP	3.0	2010/03/14 16:42:53	38.819	-122.793	3.4	3 km ( 2 mi) NNE of The Geysers, CA
MAP	3.2	2010/03/14 11:42:52	67.697	-159.603	10.0	88 km ( 55 mi) NNE of Kiana, AK
MAP	3.7	2010/03/14 07:38:00	56.142	-152.334	10.0	132 km ( 82 mi) SSE of Old Harbor, AK
MAP	3.0	2010/03/14 00:54:00	18.790	-64.732	112.1	40 km ( 25 mi) NNW of ROAD TOWN, British Virgin Islands
MAP	4.2	2010/03/13 16:32:32	32.986	-116.364	6.2	23 km ( 14 mi) ESE of Julian, CA
MAP	3.3	2010/03/13 11:03:49	18.995	-66.365	45.4	58 km ( 36 mi) N of Breñas, PR
MAP	3.1	2010/03/13 09:02:44	35.398	-98.069	5.0	14 km ( 9 mi) W of Union City, OK
MAP	4.2	2010/03/13 05:20:17	44.263	-129.322	10.0	415 km (258 mi) WNW of Bandon, OR
MAP	4.9	2010/03/13 04:53:41	44.358	-129.263	10.0	410 km (255 mi) W of Yachats, OR

Earthquakes in US West May Be Due to Natural Gas Mines

Saltwater pumped deep into the earth in a natural gas mining operation might offer a plausible, but not definitive, explanation for small earthquakes in Texas in 2008 and 2009, scientists say.

On Oct. 31, 2008, small (magnitude 3.0) tremblors shook homes in the Dallas-Fort Worth area. Similar shakes (3.3) occurred again May 2009. Now there are rumblings in not only Texas, but Oklahoma and Arkansas.

"The earthquakes were right in our backyard, and quakes don't happen too often in Texas," says seismologist Brian Stump of Southern Methodist University in Dallas, senior author on a Leading Edge journal study. "We usually only get small ones."

Some suspicions centered on wells involved in "hydraulic fracturing" of shale layers in Texas and elsewhere. The shale is cracked by injections of high-pressure water, loaded with sand, to free natural gas trapped within. The U.S. Geological Survey estimates that 200 trillion cubic feet of natural gas may reside in shales nationwide.

Stump and colleagues analyzed records from 11 quakes. Triangulating from different earthquake waves, the group narrowed the origin to about one-tenth of a mile just south of the Dallas-Fort Worth airport, atop a geologic fault about 15,000 feet down.

"It's an old fault, but it still has stresses on it, which can trigger quakes," Stump says.

About 13 fracture wells have been drilled since 2002 near the locale, but the team found the epicenter sits almost exactly on the location of a wastewater "reinjection" well, where about 9,000 barrels of saltwater a day was deposited 10,000 to 14,000 feet deep. The salty "flowback" water was pumped to the surface in the fracturing process, and disposing of such brine by reinjecting it into deep rock removes the need to treat it for safety reasons.

"These kinds of induced quakes are widely accepted in the seismological community, and it looks like they have a case here," says geophysicist Jim Dewey of the U.S. Geological Survey office in Golden, Colo. "The vast majority of wells don't have quakes associated with them, of course."

But geophysicist Shaopeng Huang of the University of Michigan in Ann Arbor cautioned in an e-mail that "a causal link between a given earthquake with a particular borehole is debatable," given the tremendous energy involved in even a minor quake.

"We are only saying a link to the well is 'plausible,' not definitive," Stump says. Still, he notes, the quakes have ceased since the saltwater reinjection was stopped at the site after a third set of tremblors in June 2009.

Leading Edge Journal; Southern Methodist University; University of Texas - Austin; USA Today; USGS.

US Earthquake List Updated - USGS

	MAG	UTC DATE-TIME y/m/d h:m:s	LAT deg	LON deg	DEPTH km	LOCATION
MAP	3.0	2010/03/10 10:05:09	33.245	-116.705	4.2	5 km ( 3 mi) E of Lake Henshaw, CA
MAP	4.9	2010/03/10 08:05:27	51.529	-173.516	57.2	89 km ( 55 mi) SSE of Atka, AK
MAP	4.9	2010/03/10 06:11:34	51.467	-173.482	44.0	96 km ( 59 mi) SSE of Atka, AK
MAP	3.1	2010/03/10 06:04:35	35.613	-96.766	5.0	5 km ( 3 mi) E of Sparks, OK
MAP	3.0	2010/03/10 04:36:38	36.060	-117.882	2.2	6 km ( 4 mi) ENE of Coso Junction, CA
MAP	3.8	2010/03/10 00:57:52	31.964	-115.903	7.0	63 km ( 39 mi) NNW of Lázaro Cárdenas, Mexico

Yellowstone Hit By Swarms of Earthquakes

Yellowstone National Park has been rattled by more than 250 earthquakes in the past two days following a period of 11 months of quiet seismic activity in the park.

The quakes have been gaining strength, with a 3.1 tremor recorded at 11:03 a.m. today. A 2.9 quake was recorded at 12:38 p.m.

Prof. Robert B. Smith, a geophysicist at the University of Utah and one of the leading experts on earthquake and volcanic activity at Yellowstone, said that the activity is a "notable swarm."

"The swarm is located about 10 miles northwest of Old Faithful, Wyo., and nine miles southeast of West Yellowstone, Montana," said Smith.

Jamie Farrell, a doctoral student in geophysics who works with Smith at the University of Utah, said that as of 3 p.m. today, 270 quakes have been recorded in the past two days.

Farrell said the quakes are occurring in an area about 5 miles from where the largest swarm of quakes was ever recorded in October 1985.

Quakes in the current swarm have ranged in magnitude of 0.5 to 3.1.

Farrell said there have been reports of at least one of the tremors being felt in the park, but he is expecting more reports as the earthquakes continue.

Smith said such swarms are "relatively common." Today's tremors seem to be normal tectonic activity, and is "not an indication" that some sort of volcanic activity will occur.

Since 1995 there have been 80 swarms, including the one that started Sunday, Farrell said.

Farrell said that there is absolutely no connection between what is occurring in Yellowstone and the magnitude 7.0 earthquake in Haiti.

"They are completely different systems," said Farrell. "They are not related."

In late December 2008 and early January 2009, Yellowstone National park experienced the second largest earthquake swarm in Yellowstone's recorded seismic history. The swarm under the north end of Yellowstone Lake consisted of 813 earthquakes with magnitudes ranging up to 3.9.

The most devastating earthquake in recent history in the Yellowstone region occurred on Aug. 17, 1959, when a magnitude 7.3 earthquake hit. It was centered near Hebgen Lake, Mont., killed 28 people and caused more than $11 million in damage.

Mike Stickney, director of earthquake studies at the Montana Bureau of Mines and Geology, said there is no way to predict when the next big one will hit.

He said it will likely occur along one of the 45 faults that line two belts - one stretching from Yellowstone National Park up to Helena, Mont., and a second one along the Montana-Idaho border.

The Yellowstone Plateau is one of the largest super-volcanoes in the world and has gone through three volcanic cycles spanning two million years, which included some of the world's largest known eruptions.

UPDATE: January 20th

The swarm of earthquakes at Yellowstone National Park which started Sunday has produced 644 tremors through 1:36 p.m. Wednesday, scientists at the University of Utah said this afternoon.

So far Wednesday, the the magnitude of the earthquakes has been in the 2.5 range or slightly lower.

Several tremors about 3.0 above were recorded on Tuesday.

As of 3 p.m. Tuesday, a total of 469 earthquakes had been recorded since Sunday, meaning another 175 quakes occurred in the past 22 hours.

The earthquakes have been reported by multiple people in the park itself, and in neighboring communities in Montana and Idaho.

Jamie Farrell, a doctoral student in geophysics at the University of Utah, said the quakes are occurring in an area about 5 miles from where the largest swarm of quakes was ever recorded in October 1985.

The area is six miles due west of Yellowstone National Park's Lower Geyser Basin, which is several miles north of Old Faithful.

Farrell said that there have been no reports of the quakes affecting the geysers in the park.

The most devastating earthquake in recent history in the Yellowstone region occurred on Aug. 17, 1959, when a magnitude 7.3 earthquake hit. It was centered near Hebgen Lake, Mont., killed 28 people and caused more than $11 million in damage.

USGS; Denver Post