Quake activity along the San Andreas fault is picking up

http://latimesblogs.latimes.com/lanow/2010/07/increased-earthquake-activity-predicted-for-california-faults.html

Increased quake activity predicted for California faults
July 9, 2010 | 5:25 pm

There is growing concern among seismologists that the 7.2 Mexicali earthquake April 4 placed more pressure on Southern California's faults, resulting in increased quake activity over the last three months.

The latest evidence was Wednesday's magnitude 5.4 Collins Valley earthquake that rolled from the mountains south of Palm Springs, leaving no major damage but rattling nerves throughout the region.

Wednesday’s quake was centered in the San Jacinto fault zone -- Southern California’s most active -- which runs 100 miles from the border northwesterly toward Riverside and San Bernardino.

Scientists had warned for some time that the Mexicali quake had transferred pressure from the Mexican border area toward the San Jacinto fault and nearby Elsinore fault – which runs 110 miles and could cause major damage in urban areas -- making quakes there more likely.

“The probability of a larger earthquake on those faults could be high within the next year or two,” said John Rundle, a physics and geology professor at UC Davis.

Rundle said the aftermath of the Mexicali quake is turning out to be significantly different than the aftermath of the two other large quakes to hit Southern California in the last two decades.

Both the 7.3 Landers quake in 1992 and the 7.1 Hector Mine quake in 1999 in the Mojave Desert resulted in aftershocks that dissipated relatively quickly. By contrast, the Mexicali quake has been followed by aftershocks and “triggered earthquakes” that are showing no signs of ending.

“This thing seems to be popping off with lots of small earthquakes, and it’s not decaying very quickly … which to me is worrisome, frankly,” he said.

Experts are particularly concerned because the northern edges of the Elsinore and San Jacinto fault zones line up, respectively, near the Whittier fault, which runs into Orange and Los Angeles counties, and the San Andreas fault. Both faults could produce catastrophic quakes.

Smaller earthquakes continue at an unexpectedly high level far north of the Mexicali quake in the Inland Empire.

“Under normal circumstances, you have a rather rapid die-off of activity after an earthquake. But in this case, the activity seems to be motoring along at a fairly high level,” Rundle said.

In contrast, Rundle’s analysis shows the probability of a large earthquake -- such as a magnitude 7 -- has decreased closer to the Mexicali quake area, such as near San Diego.

Rundle is involved in research that is looking to take patterns of smaller earthquakes that have occurred after the Mexicali earthquake and using them to forecast probabilities of where larger earthquakes will be.

“You can actually mathematically map the transfer of stress from one fault to another after an earthquake,” Rundle said. “Small earthquakes are a response to the underlying levels of stress. The higher the level of stress, the higher number of small earthquakes one typically finds. We use the patterns of small earthquakes to forecast the occurrence of larger earthquakes.”

Another piece of evidence are science stations that are built on both sides of the earthquake faults. Satellite imagery of those stations show that both sides of the faults are increasingly moving past each other, indicating growing strain.

Andrea Donnellan, a Jet Propulsion Laboratory geophysicist, likened the Mexicali quake to the initial crack in a car’s windshield.

“Over time … it cracks more,” she said. “The cracked head is where the stress is highest, and that will propagate.”

Increased strain on a fault, Donnellan said, looks like a rubber band that is increasingly stretched.

“Stretch it for a while, it will break,” she said.

The observations underscore that earthquake faults need to be looked at as a system -- similar to how weather patterns in Alaska and on the other side of the Pacific Ocean can affect California.

“You can’t look at it in a vacuum. If you look at it from a system perspective where all these faults interact with each other … you can get an idea how a fault can turn on or off an earthquake on another fault,” Donnellan said.

-- Rong-Gong Lin II

What I have noticed is that the earthquake activity has greatly increased around known volcanic areas all over the world. In the last 25 years there has been a lot of plate subduction and not much of a corresponding expulsion of fresh lava other than in Hawaii and one or two other places. There is a lot of energy under the earth's crust looking for release. So far, we've all been rather lucky that it has been in bits and spurts rather than one huge belch.

I'm also wondering if the melting of the glaciers is contributing to increased plate movement. Those acres of ice are hefty and like most things, when the plates are no longer having to support the weight of all that ice, they are more free to move around.

Ah, thank you. The glacier theory is interesting. Will continue to watch.

I checked here last week after the Oklahoma and Arkansas quakes so I could use your link to the earthquake maps. Thank you for keeping up with all of this.

3.9 Ml - SOUTHERN CALIFORNIA
Preliminary Earthquake Report Magnitude 3.9 Ml
Date-Time

* 29 Oct 2010 18:03:21 UTC
* 29 Oct 2010 11:03:21 near epicenter
* 29 Oct 2010 12:03:21 standard time in your timezone

Location 32.824N 115.967W
Depth 7 km
Distances

* 10 km (6 miles) NNE (17 degrees) of Ocotillo, CA
* 26 km (16 miles) W (278 degrees) of Seeley, CA
* 31 km (19 miles) NE (42 degrees) of Jacumba Hot Springs, CA
* 38 km (24 miles) W (276 degrees) of El Centro, CA
* 104 km (64 miles) ENE (71 degrees) of Tijuana, Baja California, Mexico

3.6 Ml - OFF COAST OF OREGON
Preliminary Earthquake Report Magnitude 3.6 Ml
Date-Time

* 30 Oct 2010 19:29:13 UTC
* 30 Oct 2010 11:29:13 near epicenter
* 30 Oct 2010 13:29:13 standard time in your timezone

Location 43.132N 126.257W
Depth 10 km
Distances

* 149 km (93 miles) WNW (287 degrees) of Port Orford, OR
* 150 km (93 miles) W (271 degrees) of Bandon, OR
* 160 km (99 miles) W (262 degrees) of Barview, OR
* 228 km (142 miles) NW (313 degrees) of Crescent City, CA
* 392 km (243 miles) SW (229 degrees) of Portland, OR
--------------------------------------
4.6 Ml - CENTRAL CALIFORNIA
Preliminary Earthquake Report Magnitude 4.6 Ml
Date-Time

* 31 Oct 2010 01:02:05 UTC
* 30 Oct 2010 18:02:05 near epicenter
* 30 Oct 2010 19:02:05 standard time in your timezone

Location 38.650N 119.570W
Depth 0 km
Distances

* 20 km (13 miles) ESE (102 degrees) of Markleeville, CA
* 26 km (16 miles) ESE (123 degrees) of Alpine Village, CA
* 26 km (16 miles) SE (128 degrees) of Mesa Vista, CA
* 47 km (30 miles) SE (131 degrees) of South Lake Tahoe, CA
* 165 km (103 miles) E (86 degrees) of Sacramento, CA
-----------------------------------------

I wonder what's going on under water...subduction, plate slip or newly formed island building. Lots of quakes there today ranging from 5.5 to the low 4s.



Wider view of the Aleutians:

4.6 Ml - SOUTHERN CALIFORNIA
Preliminary Earthquake Report
Magnitude 4.6 Ml
Date-Time

* 4 Nov 2010 19:39:59 UTC
* 4 Nov 2010 12:39:59 near epicenter
* 4 Nov 2010 13:39:59 standard time in your timezone

Location 32.868N 116.018W
Depth 2 km
Distances

* 14 km (9 miles) N (352 degrees) of Ocotillo, CA
* 32 km (20 miles) NNE (30 degrees) of Jacumba Hot Springs, CA
* 32 km (20 miles) SSE (161 degrees) of Ocotillo Wells, CA
* 44 km (27 miles) WNW (282 degrees) of El Centro, CA
* 101 km (63 miles) ENE (68 degrees) of Tijuana, Baja California, Mexico
----------------------------------------------
4.1 Ml - BAJA CALIFORNIA, MEXICO
Preliminary Earthquake Report
Magnitude 4.1 Ml
Date-Time

* 4 Nov 2010 13:23:53 UTC
* 4 Nov 2010 05:23:53 near epicenter
* 4 Nov 2010 07:23:53 standard time in your timezone

Location 31.270N 115.666W
Depth 1 km
Distances

* 17 km (11 miles) SSE (156 degrees) of Lázaro Cárdenas, Baja California, Mexico
* 65 km (40 miles) NNE (30 degrees) of Vicente Guerrero, Baja California, Mexico
* 81 km (51 miles) WNW (292 degrees) of San Felipe, Baja California, Mexico
* 112 km (70 miles) SE (126 degrees) of Ensenada, Baja California, Mexico
* 190 km (118 miles) SE (137 degrees) of Tijuana, Baja California, Mexico
-------------------------------------

A 5.5 magnitude quake hit near Atka, Alaska - which is one of the islands along the Alaska Aleutian Chain. This area is the source of an ongoing 'swarm' of earthquakes. When magnitudes begin to reach the 5.0 and larger, it suggests something larger is on the way.

There are two other areas of current 'swarms' we are watching very closely. The first is the Baja Peninsula near Mexicali, California. The second is just north of San Francisco at Clear Lake, known as 'The Geyser' geothermal field.

---------------------------------------

The Associated Press along with every other major news agency has taken notice of the ongoing Alaska Aleutian Chain earthquake swarm. This comes on the heels of concern over the Cascadia Subduction Zone predicted escalation. Some seismologists believe several fault lines are connected along the Pacific Rim which includes the San Andreas all the way north through Alaska.

Large Subduction Zone quakes are the largest earthquakes in the world and can exceed 9.0 magnitude. Because earthquake size is proportional to the fault area, the Cascadia Zone is perfectly set for "the big one" as often mentioned in recent mainstream articles. The Cascadia Subduction Zone is a very long sloping fault that stretches from mid-Vancouver Island to Northern California. It separates the Juan de Fuca and North America plates.



Cascadia Subduction Zone

My son moved back to California just in time for the big one.

BBB

3.7 Ml - GREATER LOS ANGELES AREA, CALIF.
Preliminary Earthquake Report
Magnitude 3.7 Ml
Date-Time

* 5 Nov 2010 16:06:37 UTC
* 5 Nov 2010 09:06:37 near epicenter
* 5 Nov 2010 10:06:37 standard time in your timezone

Location 33.783N 118.131W
Depth 21 km
Distances

* 3 km (2 miles) SE (133 degrees) of Long Beach, CA
* 4 km (3 miles) ESE (119 degrees) of Signal Hill, CA
* 5 km (3 miles) WNW (301 degrees) of Seal Beach, CA
* 32 km (20 miles) SSE (160 degrees) of Los Angeles Civic Center, CA

Wonder how the Alaskan pipeline is holding up with all these recent quakes.



Magnitude 5.3 - NORTHERN ALASKA
2010 November 07 00:43:23 UTC

Earthquake Details

* This event has been reviewed by a seismologist.

Magnitude 5.3
Date-Time

* Sunday, November 07, 2010 at 00:43:23 UTC
* Saturday, November 06, 2010 at 04:43:23 PM at epicenter
* Time of Earthquake in other Time Zones

Location 69.186°N, 146.225°W
Depth 9.6 km (6.0 miles)
Region NORTHERN ALASKA
Distances 135 km (85 miles) SW of Kaktovik, Alaska
135 km (85 miles) N of Arctic Village, Alaska
505 km (315 miles) N of Fairbanks, Alaska
1350 km (840 miles) NNW of JUNEAU, Alaska

Magnitude 3.1 - NORTHERN CALIFORNIA
2010 November 07 22:16:35 UTC

Earthquake Details

* This is a computer-generated message -- this event has not yet been reviewed by a seismologist.

Magnitude 3.1
Date-Time

* Sunday, November 07, 2010 at 22:16:35 UTC
* Sunday, November 07, 2010 at 02:16:35 PM at epicenter
* Time of Earthquake in other Time Zones

Location 39.622°N, 121.935°W
Depth 21.6 km (13.4 miles)
Region NORTHERN CALIFORNIA
Distances 15 km (10 miles) SW of Chico, California
35 km (20 miles) WNW of Oroville, California
60 km (35 miles) NNW of Yuba City, California
120 km (75 miles) NNW of SACRAMENTO, California

4.2 Mb - OFF COAST OF OREGON
Preliminary Earthquake Report
Magnitude 4.2 Mb
Date-Time

* 10 Nov 2010 03:53:52 UTC
* 9 Nov 2010 19:53:52 near epicenter
* 9 Nov 2010 21:53:52 standard time in your timezone

Location 43.193N 126.185W
Depth 10 km
Distances

* 144 km (90 miles) W (274 degrees) of Bandon, OR
* 146 km (91 miles) WNW (290 degrees) of Port Orford, OR
* 153 km (95 miles) W (264 degrees) of Barview, OR
* 228 km (142 miles) NW (315 degrees) of Crescent City, CA
* 383 km (238 miles) SW (229 degrees) of Portland, OR

3.6 Ml - NEVADA
Preliminary Earthquake Report
Magnitude 3.6 Ml
Date-Time

* 9 Nov 2010 22:22:00 UTC
* 9 Nov 2010 14:22:00 near epicenter
* 9 Nov 2010 16:22:00 standard time in your timezone

Location 41.729N 115.148W
Depth 0 km
Distances

* 42 km (26 miles) WSW (249 degrees) of San Jacinto, NV
* 43 km (27 miles) E (88 degrees) of Williams Cabin, NV
* 47 km (29 miles) NW (316 degrees) of Wilkins, NV
* 112 km (70 miles) NNE (27 degrees) of Elko, NV
* 293 km (182 miles) WNW (293 degrees) of Salt Lake City, UT

4.2 Mb - OFF COAST OF WASHINGTON
Preliminary Earthquake Report
Magnitude 4.2 Mb
Date-Time

* 15 Nov 2010 12:19:15 UTC
* 15 Nov 2010 03:19:15 near epicenter
* 15 Nov 2010 06:19:15 standard time in your timezone

Location 47.997N 129.347W
Depth 10 km
Distances

* 327 km (203 miles) SSW (205 degrees) of Port Hardy, BC, Canada
* 353 km (219 miles) W (265 degrees) of Neah Bay, WA
* 369 km (230 miles) W (273 degrees) of Forks, WA
* 444 km (276 miles) W (265 degrees) of Saanich, British Columbia, Canada
* 478 km (297 miles) WSW (255 degrees) of Vancouver, British Columbia, Canada

----------------------------------------------
3.7 Ml - CENTRAL CALIFORNIA
Preliminary Earthquake Report
Magnitude 3.7 Ml
Date-Time

* 15 Nov 2010 08:41:15 UTC
* 15 Nov 2010 00:41:15 near epicenter
* 15 Nov 2010 02:41:15 standard time in your timezone

Location 38.635N 119.603W
Depth 0 km
Distances

* 18 km (11 miles) ESE (109 degrees) of Markleeville, CA
* 25 km (15 miles) SE (130 degrees) of Alpine Village, CA
* 25 km (15 miles) SE (135 degrees) of Mesa Vista, CA
* 46 km (29 miles) SE (135 degrees) of South Lake Tahoe, CA
* 162 km (101 miles) E (86 degrees) of Sacramento, CA

3.5 Md - WASHINGTON
Preliminary Earthquake Report
Magnitude 3.5 Md
Date-Time

* 16 Nov 2010 15:51:08 UTC
* 16 Nov 2010 07:51:08 near epicenter
* 16 Nov 2010 09:51:08 standard time in your timezone

Location 46.559N 122.440W
Depth 9 km
Distances

* 5 km (3 miles) NE (46 degrees) of Mossyrock, WA
* 12 km (8 miles) W (271 degrees) of Morton, WA
* 30 km (18 miles) SW (220 degrees) of Elbe, WA
* 76 km (47 miles) S (179 degrees) of Tacoma, WA
* 104 km (64 miles) N (7 degrees) of Vancouver, WA

4.6 Mb - OFF COAST OF OREGON
Preliminary Earthquake Report
Magnitude 4.6 Mb
Date-Time

* 21 Nov 2010 23:46:35 UTC
* 21 Nov 2010 15:46:35 near epicenter
* 21 Nov 2010 17:46:35 standard time in your timezone

Location 43.464N 127.212W
Depth 17 km
Distances

* 230 km (143 miles) W (281 degrees) of Bandon, OR
* 234 km (146 miles) WNW (291 degrees) of Port Orford, OR
* 235 km (146 miles) W (274 degrees) of Barview, OR
* 311 km (193 miles) NW (309 degrees) of Crescent City, CA
* 429 km (266 miles) WSW (239 degrees) of Portland, OR

http://www.computerworld.com/s/article/9197339/California_s_earthquake_risk_spurs_supercomputing_efforts

California's earthquake risk spurs supercomputing efforts
IBM's 10-petaflop system will be used to run quake simulations in 2011

By Patrick Thibodeau
November 20, 2010 06:11 AM ET
Comments (2)
Recommended (12)

Computerworld - NEW ORLEANS -- The rush to build more powerful supercomputers is part of a larger race to solve some of mankind's biggest problems and threats, and one person on the front line of that effort is Thomas Jordan, the director of the Southern California Earthquake Center.

"We are very concerned about the current state of the faults in Southern California," said Jordan, who described the San Andreas Fault as "locked and loaded and ready to roll" and one day unleash a sizable earthquake.

Jordan and his team have been running simulations of how an earthquake might affect southern California on the Jaguar system at Oak Ridge National Laboratory. Until this week Jaguar had been the world's fastest supercomputer, at 1.75 petaflops. But it has now been eclipsed by China's 2.5-petaflop system, Tianhe-1A, according to the semiannual Top500 ranking of the world's most powerful machines.

The point of building a supercomputer is to improve research capabilities. Supercomputers allow scientists to study in simulated environments everything from the effect of the BP oil spill on coastlines to the behavior of cells at an atomic level and the impact of an earthquake.

"Normally, we learn these things from just hard experience [but] we think we can learn a lot about what to do from simulation," said Jordan. "We can't predict the future; we can't predict earthquakes. But we can really begin to do some really detailed simulations, and that makes people think."

The idea is to use simulations to show how to prepare for an earthquake. With increasing computer power, simulations can be built that model how an earthquake, at different magnitudes, will hit neighborhoods, affect infrastructure and rock buildings; they could also show where and how an earthquake creates fire risks, among other things.

Jordan is preparing his applications to run on Blue Waters, a planned 10-petaflop system (meaning it would deliver 10 quadrillion calculations per second) that's due to be up and running next year at the National Center for Supercomputing Applications (NCSA) at the University of Illinois, Urbana-Champaign. That scale of computing will mean that an application with a runtime of 4,000 processor hours on Jaguar can be completed in just 770 hours on Blue Waters, said Jordan.

A processor hour is equivalent to one hour on one processing core.

In a presentation at the SC10 supercomputing conference here this week, Jordan ran a video showing a simulation of the energy from a magnitude 8 earthquake being distributed around Southern California. It wasn't a Hollywood production, with scenes of buildings shaking and roadways cracking, but an intensely graphical display of sharp yellow and red peaks and valleys moving swiftly over a map of the region, indicating where an earthquake might do the most damage. The product of mountains of data, the graphics on the map were just as alarming as any images Hollywood produces.

There is urgency to Jordan's need for more computing power. The Pacific Plate is moving northwest at a rate of about 16.4 feet every 100 years. "That means we've got to have big earthquakes every 100 years," said Jordan.

The 1906 San Francisco earthquake, which had about 16 feet of displacement, produced a 7.8 magnitude earthquake. But in the area around the southern San Andreas Fault, the last big quake was in 1857, and further south, there hasn't been a big one since 1680, said Jordan. Two years ago, the California Geological Survey and the earthquake center estimated that there's a 99% probability of magnitude 6.7 or larger quake during the next 30 years in California.

It could be years before there's a big earthquake, said Jordan. But "I can tell you all the seismologists are very nervous."

Blue Waters, which is being built by IBM, will have the fastest cores "of its generation." It also has the fastest memory infrastructure and fastest interconnect, "which means that data movement is much faster in the Blue Waters system than other systems of today -- and actually [faster than] many of the systems that will be in place next year and the following years," said William Kramer, the deputy director of the Blue Waters Project at the NCSA, which is overseeing development of the system.

"The combination of not just how fast the cores go, but how fast can you get data to them, is really the secret why Blue Waters will be such a step forward," said Kramer.

The system's fundamental building block is a 32-core SMP -- four eight-core Power 7 chips -- with shared memory and one operating system image, yielding about a teraflop of aggregated computing power, said Kramer. The interconnect is about 1.1TB per second, and the system was designed to reduce the number of hops data must take, because each hop adds time. "In the normal case, to go anywhere in the system from any one core to any other core; worst case it takes five hops," said Kramer.

The machine will have more than 300,000 processing cores.

The hardware will arrive next year, with scientific research expected to begin late in the year. The system takes up around 5,000 square feet of space -- twice that when you add in the supporting infrastructure and the advanced storage it needs. A new building was built this year to house Blue Waters and other systems, and t was designed with future needs in mind. It has the potential to support up to 100 megawatts of power, with Blue Waters itself using around 12MW. Blue Waters relies on water cooling, as well as the cooler Illinois air to stay chilled, and it will be allowed to run in a hotter environment -- one with temperatures above 80 degrees.

The entire project, including the computer, is expected to cost more than $300 million.

The drive for more computing power is spurred by a number of factors. There is the need for speedy results, particularly in an emergency situation such as when healthcare researchers are modeling the spread of a virus like H1N1.

Blue Waters will be followed by two 20-petaflop systems in 2012, one at Oak Ridge National Laboratory and the other at Lawrence Livermore National Laboratory.

One reason scientists need large systems is for their ability to run thousands or even millions of the same type of simulations. The approach is called "uncertainty quantification," where scientists run simulations with different inputs and physics, such as those used in weather forecasting, and then develop a statistical analysis, producing a result with "higher fidelity," or better predictive capability, said Karl Schulz, associate director of high-performance computing at the Texas Advanced Computing Center at the University of Texas in Austin.

There is also a strong desire to run "multi-physics," which are simulations that bring together, for instance, fluid mechanics and structural dynamics and chemistry, said Schulz.

The need for systems that can handle these big problems is one of the reasons an effort to build an exascale computer is important, Schulz said. An exascale system would be 1,000 times more powerful than a petaflop system, and is the kind of system Jordan is anxious to use. The first one is expected to be ready sometime around 2018.

A bunch of average-sized ones all over the US today.

4.2 M - OKLAHOMA
Preliminary Earthquake Report
Magnitude 4.2 M
Date-Time

* 24 Nov 2010 22:48:30 UTC
* 24 Nov 2010 16:48:30 near epicenter
* 24 Nov 2010 16:48:30 standard time in your timezone

Location 35.627N 97.246W
Depth 7 km
Distances

* 6 km (4 miles) SW (232 degrees) of Luther, OK
* 8 km (5 miles) ESE (121 degrees) of Arcadia, OK
* 8 km (5 miles) NNE (30 degrees) of Jones, OK
* 31 km (19 miles) ENE (58 degrees) of Oklahoma City, OK
* 317 km (197 miles) N (352 degrees) of Dallas, TX
--------------------------------------
3.8 Ml - CENTRAL ALASKA
Preliminary Earthquake Report
Magnitude 3.8 Ml
Date-Time

* 25 Nov 2010 01:04:52 UTC
* 24 Nov 2010 16:04:52 near epicenter
* 24 Nov 2010 19:04:52 standard time in your timezone

Location 63.101N 150.788W
Depth 121 km
Distances

* 81 km (50 miles) N (359 degrees) of Petersville, AK
* 84 km (52 miles) NNW (335 degrees) of Chase, AK
* 91 km (56 miles) NNW (346 degrees) of Trapper Creek, AK
* 219 km (136 miles) NNW (346 degrees) of Anchorage, AK
------------------------------------
4.6 Mb - OFF COAST OF OREGON
Preliminary Earthquake Report
Magnitude 4.6 Mb
Date-Time

* 25 Nov 2010 02:04:40 UTC
* 24 Nov 2010 17:04:40 near epicenter
* 24 Nov 2010 20:04:40 standard time in your timezone

Location 43.852N 127.912W
Depth 10 km
Distances

* 294 km (183 miles) WNW (287 degrees) of Bandon, OR
* 295 km (184 miles) WNW (282 degrees) of Barview, OR
* 300 km (186 miles) W (281 degrees) of North Bend, OR
* 382 km (237 miles) NW (309 degrees) of Crescent City, CA
* 456 km (284 miles) WSW (248 degrees) of Portland, OR
--------------------------------------
3.8 Ml - CENTRAL CALIFORNIA
Preliminary Earthquake Report
Magnitude 3.8 Ml
Date-Time

* 25 Nov 2010 04:01:15 UTC
* 24 Nov 2010 20:01:15 near epicenter
* 24 Nov 2010 22:01:15 standard time in your timezone

Location 36.030N 117.787W
Depth 3 km
Distances

* 15 km (9 miles) E (96 degrees) of Coso Junction, CA
* 32 km (20 miles) SE (144 degrees) of Olancha, CA
* 32 km (20 miles) SW (214 degrees) of Darwin, CA
* 47 km (29 miles) NNW (348 degrees) of Ridgecrest, CA
* 224 km (139 miles) N (11 degrees) of Los Angeles Civic Center, CA
-----------------------------------
Magnitude 3.0 - ARIZONA
2010 November 24 14:58:21 UTC

Earthquake Details

* This event has been reviewed by a seismologist.

Magnitude 3.0
Date-Time

* Wednesday, November 24, 2010 at 14:58:21 UTC
* Wednesday, November 24, 2010 at 07:58:21 AM at epicenter
* Time of Earthquake in other Time Zones

Location 36.818°N, 111.791°W
Depth 5.8 km (3.6 miles)
Region ARIZONA
Distances

* 25 km (16 miles) NNW (331°) from Bitter Springs, AZ
* 31 km (20 miles) SSW (202°) from Big Water, UT
* 31 km (20 miles) WSW (250°) from Page, AZ
* 70 km (44 miles) ESE (110°) from Kanab, UT
* 204 km (127 miles) E (89°) from Mesquite, NV
* 314 km (195 miles) ENE (76°) from Las Vegas, NV
---------------------------------------

An unusual quake off the east coast today:



3.9 Ml - OFF EAST COAST OF UNITED STATES
Preliminary Earthquake Report
Magnitude 3.9 Ml
Date-Time

* 30 Nov 2010 15:45:59 UTC
* 30 Nov 2010 10:45:59 near epicenter
* 30 Nov 2010 09:45:59 standard time in your timezone

Location 39.799N 71.927W
Depth 6 km
Distances

* 127 km (79 miles) SSE (153 degrees) of Quogue, NY
* 127 km (79 miles) SSE (162 degrees) of Southampton, NY
* 128 km (79 miles) SSE (148 degrees) of West Hampton Dunes, NY
* 188 km (117 miles) SE (145 degrees) of Bridgeport, CT
* 197 km (122 miles) ESE (120 degrees) of New York, NY


Tectonic Summary

EARTHQUAKES IN THE STABLE CONTINENTAL REGION
Most of North America east of the Rocky Mountains has infrequent earthquakes. Here and there earthquakes are more numerous, for example in the New Madrid seismic zone centered on southeastern Missouri, in the Charlevoix-Kamouraska seismic zone of eastern Quebec, in New England, in the New York - Philadelphia - Wilmington urban corridor, and elsewhere. However, most of the enormous region from the Rockies to the Atlantic can go years without an earthquake large enough to be felt, and several U.S. states have never reported a damaging earthquake. The earthquakes that do occur strike anywhere at irregular intervals.

Earthquakes east of the Rocky Mountains, although less frequent than in the West, are typically felt over a much broader region. East of the Rockies, an earthquake can be felt over an area as much as ten times larger than a similar magnitude earthquake on the west coast. A magnitude 4.0 eastern U.S. earthquake typically can be felt at many places as far as 100 km (60 mi) from where it occurred, and it infrequently causes damage near its source. A magnitude 5.5 eastern U.S. earthquake usually can be felt as far as 500 km (300 mi) from where it occurred, and sometimes causes damage as far away as 40 km (25 mi).

FAULTS
Earthquakes everywhere occur on faults within bedrock, usually miles deep. Most of the region's bedrock was formed as several generations of mountains rose and were eroded down again over the last billion or so years.

At well-studied plate boundaries like the San Andreas fault system in California, often scientists can determine the name of the specific fault that is responsible for an earthquake. In contrast, east of the Rocky Mountains this is rarely the case. All parts of this vast region are far from the nearest plate boundaries, which, for the U.S., are to the east in the center of the Atlantic Ocean, to the south in the Caribbean Sea, and to the west in California and offshore from Washington and Oregon. The region is laced with known faults but numerous smaller or deeply buried faults remain undetected. Even most of the known faults are poorly located at earthquake depths. Accordingly, few earthquakes east of the Rockies can be linked to named faults. It is difficult to determine if a known fault is still active and could slip and cause an earthquake. In most areas east of the Rockies, the best guide to earthquake hazards is the earthquakes themselves.