West Coast Earthquakes

2011 Southern California Earthquakes

2011-03-17T20:08:00.000-07:00

10 Most recent 3.0+ earthquakes in Southern California

updated: 03/17/11 08:03 PM (West Coast Time)

MAG	DATE	LOCAL TIME	LOCATION	DEPTH (KM)
3.1	3/17/2011	10:30 AM	17 WNW Pinnacles, CA	7.9
3.4	3/17/2011	10:18 AM	14 NW Pinnacles, CA	5.8
3.0	3/16/2011	10:55 PM	5 NE San Simeon, CA	2.1
3.3	3/15/2011	12:15 AM	36 SW Ensenada, MX	7.0
3.6	3/13/2011	11:30 PM	54 SSE Calexico, CA	10.0
3.4	3/10/2011	8:51 PM	16 NNW Tehachapi, CA	5.4
3.2	3/10/2011	7:56 AM	17 N Searles Valley, CA	4.7
3.2	3/9/2011	5:55 AM	36 SSE Calexico, CA	10.0
3.0	3/8/2011	8:17 PM	1 N Big Bear City, CA	6.7
3.1	3/8/2011	12:46 PM	13 WSW Calexico, CA	12.9
MORE 2011 QUAKES
Previous Years

4.9 & 4.5 | 8:08pm | Borrego Springs, Ca. | June 12th, 2010

2010-06-13T00:52:00.000-07:00

At 8:08pm, on Saturday night, two moderate earthquakes struck in the Anza-Borrego Desert. A 4.9 and 4.5 magnitude earthquake hit approximately 9 miles north northwest of Borrego Springs, California. Both earthquakes occurred just south of the Anza Gap and are related to San Jacinto Fault.

The first earthquake was a 4.9 magnitude quake which struck at 8:08pm.

The second earthquake was a 4.5 magnitude aftershock that struck at 8:09pm.

Because the earthquakes struck so close together, only 24 seconds separated the two seismic events, the USGS had trouble determining the exact magnitude, location, and whether they had one or two events recorded. Within the first hour, the magnitudes were revised multiple times and the sizes ranged from 4.4 to 4.9 in magnitude.

At the time of this posting, the official answer seems to be that two quakes occurred, a magnitude 4.9 and a 4.5.

The epicenter of both quakes were far from any major town. Anza and Borrego Springs were the closest towns to the epicenter, both small desert communities. The San Diego Union Tribune quoted a clerk at the Borrego Springs Resort as saying, "...the building’s glass shook but did not break, and the resort had no damage." No damage or injuries were expected elsewhere as well.

Despite the quake being considered small to moderate, it was widely felt strongly by many in Imperial, San Diego, Orange, and San Bernandino county areas, as well as by people in the Los Angeles city area. Additionally, felt reports were received from Tijuana, Tecate, and Mexicali, Mexico.

Some of the communities that turned in the most felt reports included Carlsbad, Ramona, La Quinta, Santee, Escondido, San Diego, Poway, Encinitas, Temecula, San Marcos, Fallbrook, Palm Desert, Murrieta, and Oceanside.

I personally felt this quake while I was at work in Carlsbad, California. I was in an office building at the time, ground floor, in a hallway when the earthquake struck. It felt like something hit the building. The entire building suddenly shook violently. I stopped what I was doing and looked down the hallway. I heard the shaking travel through the building from one side to the other, east to west. I knew immediately that it was an earthquake. However, after the initial jolt, I could not feel any shaking afterward and no apparent damage had been done.

The following recording was made back home while I was at work. I have set up an earthquake cam in an attempt to capture a quake on video. Unfortunately, there is no sound, but what you will see is at least three things move in the shot. (According to the clock in the video) At 8:07pm and 49 seconds, the p-wave hits, effecting the chimes and the pendulum. A 8:07pm and 59 seconds, the pendulum and the ball move, almost in unison. You have to watch for the ball closely, though. It's very subtle. For the remainder of the video, the chimes and pendulum shake until they eventually calm down.

[Magnitudes and locations are subject to change as the USGS continues to review the data.]

-Article written by Tim "Lance" Sherwood of Oceanside, Ca.

3.1 | 4:02am | Ocotillo, Ca. | June 9th, 2010

2010-06-09T04:43:00.000-07:00

At 4:02am, on Wednesday morning, a 3.1 magnitude earthquake hit 6 miles southeast of Ocotillo, California. The earthquake occurred just north of the Mexican border, in the desert, and is possibly related either to the Yuha Wells Fault or the extreme northern edge of the Laguna Salada Fault. The earthquake appears to be an aftershock of the 7.2 Baja earthquake sequence.

A 1.9 magnitude aftershock was detected just two minutes later.

The 3.1 magnitude earthquake was not reported as felt by anyone to the USGS.

The epicenter of the 3.1 quake is located in the desert where no major towns are immediately nearby. Due to the minor magnitude and rural terrain, no damage or injuries are expected.

The closest communities are Ocotillo, Ocotillo Wells, Jacumba, Seeley, Calixico, Mexicali, Santa Isabel, El Centro, Brawley, Plaster City, and the closest major US city is San Diego.

[Magnitudes and locations are subject to change as the USGS reviews the automated data.]

3.7 | 4:59pm | Santa Monica Bay, Ca. | June 7th, 2010

2010-06-07T18:03:00.000-07:00

At 4:59pm, on Monday evening, a 3.7 magnitude earthquake hit 4 miles west of Hermosa Beach, California. Earlier in the morning, a 3.5 magnitude hit 3 miles west of Hermosa Beach, making the 3.5 a preshock to the 3.7 this evening.

The earthquake occurred just off the coast of the LA area and may be associated with either the Redondo Canyon or Palos Verdes fault zones. The epicenter was located just north of both fault systems.

Approximately an hour after the 3.7 magnitude quake, close to 3200 felt reports were given to the USGS, most of which were centered around the LA metro area. The highest number of reports, 202, came from the Manhattan Beach area. It was reported being felt as far north as Bakersfield, as far east as Riverside, and as far south as Capistrano Beach.

Due to the minor magnitude, no damage or injuries are expected.

[Magnitudes and locations are subject to change as the USGS reviews the automated data.]

3.3 & 3.2 | 1:32pm & 1:41pm| Big Bear City, Ca. | June 7th, 2010

2010-06-07T13:38:00.000-07:00

At 1:32pm, on Monday afternoon, a 3.3 magnitude earthquake hit 4 miles north of Big Bear City, California. Nine minutes later, a 3.2 earthquake struck in the same location. A 2.6 aftershock followed a minute later.

The earthquakes occurred away from town, closer to Highway 18, going down the mountain on the north side. It occurred deep in the San Bernandino Forest. Due to the minor magnitude and rural location, no damage or injuries are expected.

Approximately 20 minutes after the two 3.0+ quakes, only 6 felt reports were given to the USGS. All six came from the area of Big Bear.

Before these quakes, it would appear that a small handful of microquakes, ranging from magnitudes of 1.1 to 2.6, began at 9:23am this morning. These may have been preshocks to the 3.0+ quakes seen this afternoon.

In 1992, a 7.3 earthquake struck near Landers, California. Just three hours later, a 6.5 earthquake shook the vicinity of Big Bear, California. The closest fault to Big Bear, California, is the San Andreas fault.

[Magnitudes and locations are subject to change as the USGS reviews the automated data.]

3.5 | 2:17am | Santa Monica, Ca. | June 7th, 2010

2010-06-07T02:28:00.000-07:00

At 2:17am, on Monday morning, a 3.5 magnitude earthquake hit 3 miles west of Hermosa Beach, California.

The earthquake occurred just off the coast of the LA area and may be associated with either the Redondo Canyon or Palos Verdes fault zones. The epicenter was located just north of both fault systems.

Approximately 15 minutes after the quake, more than 720 felt reports were given to the USGS, most of which were centered around the LA metro area. The highest number of reports, 88, came from the Manhattan Beach area. It was reported being felt as far north as Chatsworth, as far east as Covina, and as far south as Irvine.

Due to the minor magnitude, no damage or injuries are expected.

[Magnitudes and locations are subject to change as the USGS reviews the automated data.]

4.1 | 11:10am | Ocotillo, Ca. |June 3rd, 2010

2010-06-03T17:47:00.000-07:00

At 11:10am, on Thursday morning, a 4.1 magnitude earthquake hit 6 miles east southeast of Ocotillo, California. The earthquake occurred just north of the Mexican border, in the desert, and is possibly related either to the Yuha Wells Fault or the extreme northern edge of the Laguna Salada Fault. The earthquake appears to be an aftershock of the 7.2 Baja earthquake sequence.

Earlier in the morning, a 3.2 earthquake occurred near Anza and a 3.1 earthquake occurred near Salton City, California. These three earthquakes occurred within 10 hours of each other and, two months after the Baja quake, this is showing signs that seismic activity in the region is not going quiet just yet.

The 4.1 magnitude earthquake was felt as far north as Palm Springs, as far northwest as Irvine, as far west as San Diego, as far east as Mexicali, and south into Mexico.

The epicenter of the 4.1 quake is located in the desert where no major towns are immediately nearby. Due to the moderate magnitude and rural terrain, no damage or injuries are expected.

[Magnitudes and locations are subject to change as the USGS reviews the automated data.]

3.1 | 7:15am | Salton City, Ca. | June 3rd, 2010

2010-06-03T07:38:00.000-07:00

At 7:15am, on Thursday morning, a 3.1 magnitude earthquake hit 6 miles west southwest of Salton City, California. The earthquake occurred west of the Salton Sea, in the desert, at the southern most tip of the San Jacinto fault system.

Earlier in the morning, at 1:44am, a 3.2 microquake occurred near Anza which is along the same San Jacinto fault. It is possible that the two quakes are reacting to the same stress due to the close proximity of time and location, as well as being along on the same fault system.

At the time of this posting, no damage or felt reports were posted to the USGS. The epicenter of the 3.1 quake is located in the desert where no major towns are nearby. Due to the low magnitude and rural terrain, no damage or injuries are expected. A 1.4 aftershock occurred at 7:20am.

[Magnitudes and locations are subject to change as the USGS reviews the automated data.]

3.2 | 1:44am | Anza, Ca. | June 3rd, 2010

2010-06-03T01:50:00.000-07:00

At 1:44am, on Thursday morning, a 3.2 magnitude earthquake hit 12 miles east southeast of Anza, California. The earthquake occurred just East of the "Anza Gap" near the San Jacinto Fault system.

At 1:48am, a 1.4 microquake was shown to be near Hemet, approximately 25 miles up the same fault to the northwest. It is possible that the two quakes are reacting to the same stress due to the close proximity of time and location, as well as being along on the same fault system.

No damage or felt reports were posted to the USGS. The epicenter of the 3.2 quake is located in the mountains where no major towns are nearby. Due to the low magnitude and rural terrain, no damage or injuries are expected. The 1.4 magnitude quake is considered a "microquake" and is generally too small be to be felt.

[Magnitudes and locations are subject to change as the USGS reviews the automated data.]

3.8 | 7:50am | Ocotillo, Ca. | May 29th, 2010

2010-05-29T07:59:00.000-07:00

At 7:50am, on Saturday morning, a 3.8 magnitude earthquake hit 7 miles east southeast of Ocotillo, California. This appears to be continued stress from the 7.2 magnitude Baja quake of April 4th. It may be related to the extreme north end of the Laguna Salada Fault, or more than likely the quake relates to the Yuha Wells Fault.

This local region has gone relatively quiet, however, this is the first 3.0+ magnitude quake in the area immediately north of the border of Mexico since the 4.2 magnitude earthquake that struck 12 miles southeast of Ocotillo at 5:21am on May 24th.

15 minutes after the 3.8, no damage or felt reports were posted to the USGS. The epicenter is located in the desert. No damage or injuries are expected.

[Magnitudes and locations are subject to change as the USGS reviews the automated data.]

2.5 Magnitude Earthquake by Port Hueneme, CA

2010-05-26T01:22:00.000-07:00

At 11:22pm, a 2.5 magnitude earthquake hit 12 miles southeast of Port Hueneme, CA. Two hours after the quake, only 18 people in the local area had reported feeling it to the USGS. There were no reports of damage nor injuries and none were expected.

The magnitude and location is subject to change as the USGS reviews that data.

This micro earthquake was the latest in a slight increase of activity off the coast in the Channel Islands Region.

On May 15th, 2010, at 8:19pm, there was a 3.9 magnitude earthquake 10 miles southeast of Oxnard, California. That same night, there was a 2.6 micro quake by Ontario and a 3.0 in the Greater Los Angeles area.

3.6 | 4.3 Downtown San Diego Earthquakes

2010-05-25T23:12:00.000-07:00

At 8:52 pm, a 3.6 magnitude earthquake hit 11 miles west southwest of downtown San Diego.

At 8:57pm, a 4.3 magnitude earthquake hit 38 miles southwest of Imperial Beach.

Both earthquakes hit 5 minutes apart and both were off the coast of downtown San Diego. This is a change in activity as both quakes occurred far from the Baja aftershock sequence. There were no immediate reports of damage or injuries and none would be expected due to the moderate to low magnitude of both quakes.

The magnitudes and locations are subject to change as the USGS reviews that data.

The last earthquake in this region was a 3.5 magnitude quake 36 miles southwest of Rosarito, Mexico, on March 24, 2010.

Before that, there was also a 4.4 and two 3.6 magnitude earthquakes between February 1st and February 3rd earlier this year in the same general location off the coast.

Southern California Shakes with a 4.4 Earthquake

2010-03-16T04:29:00.000-07:00

A light earthquake with a magnitude 4.4 shook a section of Southern California shortly after 4am this morning (March 16, 2010).

The quake was centered in the Whittier area of the San Gabriel Valley. This is the same general area that was struck by the deadly 5.9 Whittier Narrows earthquake in 1987.

At this time no damage or injuries have been reported. The quake was felt as far south as northern San Diego County and as far North as Southern Kern County.

Moderate Quake Shakes Southern California

2009-12-30T11:24:00.000-08:00

A moderately strong 5.8 earhtquake struck the California/Mexico border near Calexico at 10:48am (Local time) on December 30, 2009. The quake was felt widely throughout Southern California, Northern Baja and Southern Arizona.

The quake Was felt as far away as Los Angeles and Phoenix.

Reports of damage or injuries have not come in yet. However, a quake of this size could cause local damage.

The quake occurred 30 miles south east of the heavily populated Calexico/Mexicali area. Quakes in this area are not uncommon. Quakes of 5.0+ have have struck this in recent years.

As of 30 minutes after the quake, there have been a number of sizable aftershocks including a 4.9 at 10:53, and a 4.0 at 11:07.

Minor Earthquake Shakes San Francisco

2009-10-13T20:37:00.000-07:00

8:30 PM - Tuesday October 13, 2009

An Earthquake with a magnitude of 3.7 has occurred area near Pleasanton, southeast of San Francisco.

The quake struck at 8:27 PM local time and was felt throughout the bay area and as far south as Gilroy.

No damage or injuries have been reported.

3.8 Earthquake Recorded off the Coast of Southern California

2009-10-08T01:15:00.000-07:00

October 7, 2009

A shallow earthquake measuring 3.8 on the richter scale occurred near San Clemente Island. This is due west of San Diego.

The earthquake struck at 8:31 in the evening local time. No damage and no injuries were reported as a result of this quake. The quake was felt in parts of southern Orange county and coastal sections of San Diego counties.

5.1 Shakes Central California

2009-10-01T03:18:00.000-07:00

An earthquake with a preliminary magnitude of 5.1 has struck the Central California region near Owens Lake, about 50 miles north of Ridgecrest. The quake struck at 3:01 AM local time and was immediately followed by several small aftershocks. Largest reported aftershock has been a 3.3 at 3:03 am.

This area is prone to earthquakes of this size. Damage and injuries have not been reported and are not expected due to the remote location and sparse population.

Past Magnitude 5.0+ earthquakes in the same area

5.2 July 17, 2001
5.0 March 7, 1998
5.2 March 6, 1998
5.3 November 27, 1996

3.9 Quake Shakes Fontana and the Inland Empire

2008-03-09T13:46:00.000-07:00

An earthquake with a magnitude of 3.9 occurred about 4 miles north of Fontana. It struck at 1:22 a.m. Local time on March 9, 2008. An aftershock measuring 3.1 occurred about a minute later.

A quake of this size is not expected to cause damage or injuries. It was widely felt throughout the Inland Empire, Riverside and parts of Los Angeles and Orange counties.

Quakes in this area are not uncommon. A 4.4 in January of 2005 was preceded by several smaller foreshocks.

LOCATION MAP (click to enlarge):

6.0 Nevada Earthquake

2008-02-22T02:13:00.000-08:00

A strong 6.0-magnitude earthquake struck a sparsely-populated region of northern Nevada on Thursday, damaging buildings and rupturing water and gas mains. Fortunately there were no serious injuries reported.

Here is a wide view of the immediate area followed by a closer view (click to enlarge).

NEWS REPORT

QUAKE FOOTAGE

A lot of people ask why the clips in this video stop just as the shaking starts. The reason is because the electricity went out and the recordings stopped.

Baja Continues to Shake

2008-02-12T03:08:00.000-08:00

The sequence of earthquakes coming out of Northern Baja is quite impressive and is not showing any signs of slowing down. It resembles an aftershock sequence you might see after a 6+ earthquake. But there was no 6+ earthquake. In fact, the quake which started this was only a 5.4.

The quake was originally posted as a 5.4 and later downgraded to a 5.1. There is still some debate over the true magnitude of this quake. It will take some time to determine the actual magnitude. It should be somewhere between 5.1 and 5.5.

As of the time of this report the 5.4 quake has been followed by at least 35 aftershocks with a magnitude of 3.0 or greater. Five have been greater than 4.0 and two have been 5.0 or greater. In total there have been over 200 aftershocks.

How does this compare with previous quakes in the area? Data from previous years shows that in May of 2006 a 5.4 earthquake produced 16 aftershocks of 3.0 or greater. In February of 2002 a 5.7 quake in the same area produced nearly fifty 3.0+ aftershocks.

The question that I'm sure everyone is asking is whether something bigger and more destructive is on the way. Nobody can say for sure. The 5.7 quake in 2002 was preceded by increased seismic activity which started in December of 2001.

It is always best to be prepared. Plan as if a stronger quake is on the way. Make sure you are prepared by having a supply of bottled water and non-perishable food. Always sleep with a pair of shoes and a flash light near your bed. Make sure there are no loose items or furniture that could fall and hurt someone.

It's a good idea to always be prepared. The mainshock is usually the largest and most destructive, and waiting until after the mainshock to get prepared is a bad idea.

Here is a link for more tips on how to prepare for an earthquake and what to do after one strikes.ALWAYS BE PREPARED

Here is our latest image showing the region affected by these quakes (click on it to enlarge):

Two 6.5 Quakes Rock Vancouver Island

2008-01-05T04:10:00.000-08:00

The area between Vancouver Island and Queen Charlotte Islands off the west coast of British Columbia was the location of two quakes. The first, a 5.3, struck at 2:39 am Saturday morning and the second and much stronger 6.5 quake struck about 20 minutes later at 3:01 am.

To soon to know if there is any significant damage or injuries. The quake was about 75 KM (48 miles) off the southern tip of Kunghit Island, which is part of the Queen Charlotte Islands.

The quakes were about 155 KM (95 miles) north-northwest of Scott Islands, Just north of Vancouver Island. This location is about 575 miles NNW of Seattle Washington.

A 6.5 earthquake is not likely to produce any damaging tsunamis.

As I'm typing this, a second 6.5 quake has been reported in the same area. This new quake truck at 3:44 AM. I will update the maps later today, when more information becomes available.

4.0 Quake shakes Washington State

2007-11-27T02:15:00.000-08:00

A 4.0 quake shook the Olympic Peninsula Monday evening. The quake was felt widely through the area. So far there have been no reports of injuries or damage.

The quake struck at 10:18 in the evening (11/26/07) near Brinnon, which is about 30 miles west of Seattle.

A 3.2 earthquake occurred in the same area this last January. Both quakes are shown on the following map images.

The first (left) is a regional view of the area, and the second (right) is a closer view (click to see full size).

Strong Shake Felt in Northern California

2007-10-30T22:40:00.000-07:00

An Earthquake with a preliminary magnitude of 5.6 has shaken an area northeast of San Jose. The quake occurred at 8:04 PM local time on 10/30/07.

The quake was centered in a remote section of the Calaveras Valley about three miles southeast of the Calaveras Reservoir. This location is about 7 miles east of Milpitas, 9 miles northeast of San Jose, 14 miles southeast of Freemont.

At this time there has been no reports of injuries or damage. This may change as information regarding the quake is still coming in.

CLICK HERE for the latest information and discussion regarding this quake.

4.5 Earthquake hits Los Angeles area

2007-08-24T00:24:00.000-07:00

LOS ANGELES (Reuters) - A small earthquake hit the northern Los Angeles area just before 1 a.m. (4 a.m. EDT) on Thursday (August 9, 2007), waking residents across a broad swathe of the area, but there were no immediate reports of significant damage.

The 4.5 preliminary magnitude quake was centered 4.1 miles north-northwest of the suburb of Chatsworth, according to the U.S. Geological Survey. It was extremely shallow, at only 3 miles deep.

Residents reported a strong jolt, followed by a lot of shaking. Some said pictures fell off walls, water sloshed around in toilets, and television sets wobbled on cabinets. A police spokesman said the quake triggered hundreds of alarms.

It was followed by two aftershocks, both with a preliminary 1.6 magnitude.

Chatsworth is just six miles west of Northridge, the epicenter of the magnitude 6.7 quake that killed 57 people and injured more than 9,000 in 1994.

4.3 quake felt near Watsonville

2007-07-02T14:49:00.000-07:00

UPDATED 7/2/07

An earthquake with a preliminary magnitude of 4.3 struck the Watsonville area monday afternoon. The quake struck at 12:58 PM and was felt throughout the region and up into the San Francisco bay area.

There have been no injuries and damage has been limited to a few items falling off store shelves.

Two smaller quakes occured in this area last week. CLICK HERE to read our report on those quakes.

If you felt this earthquake and would like to share your story (or read other accounts), please check our message board.

Don't forget to check out our 2007 quake map to see other Northern California quakes in 2007. Our list of previous years quakes can be found on the right side of our web site.

Small Quakes Rattle Watsonville

2007-06-27T22:22:00.000-07:00

UPDATED: 7/2/07

A new 4.3 quake has been reported in this area. CLICK HERE for our special report.

Residents in Watsonville were shaken by a series of small quakes late this afternoon. The three quakes, measuring 3.0, 3.2 and 3.0, all occurred within 15 minutes of each other.

The earthquakes were felt within the Watsonville and surrounding communities. The shaking has been described as a gentle rumbling ending in a sharp jolt.

If you felt this earthquake and would like to share your story (or read other accounts), please check our message board.

Be sure to check out our 2007 quake map to see other Northern California quakes in 2007. Our list of previous years quakes can be found on the right side of our web site.

Powerful Earthquake Off the coast of Papua New Guinea

2007-06-27T21:08:00.000-07:00

A strong earthquake with a preliminary magnitude of 6.7 has occured off Bougainville Island.

The following is a release by the United States Geological Survey, National Earthquake Information Center: An earthquake occurred about 220 km (135 miles) SSW of Arawa, Bougainville, PNG or about 825 km (520 miles) E of PORT MORESBY, Papua New Guinea at 8:52 PM MDT, Jun 27, 2007 (Jun 28 at 12:52 PM local time in Papua New Guinea). The magnitude and location may be revised when additional data and further analysis results are available. There have been no reports of damage.

------------
WIKI:
The Bougainville Province, also known as North Solomons Province, is an autonomous province in Papua New Guinea and is the largest of the Solomon Islands group. The largest island is Bougainville Island, and the capital is Arawa. The province also includes the adjacent island of Buka and assorted outlying islands including the Carterets. The population of the province is 175,160 (2000 census). Bougainville Island is ecologically and geographically, although not politically, part of the Solomon Islands. Buka, Bougainville, and most of the Solomons are part of the Solomon Islands rain forests ecoregion. MORE

Strong quake jolts southern part of Java

2007-06-26T22:08:00.000-07:00

Deutsche Presse-Agentur

Jakarta - A 6.0-magnitude earthquake struck the southern part of Indonesia's Java island Wednesday morning, but there were no immediate reports of injuries or damage, an official said.

The tremblor shook at about 5:23 am (2223 GMT Tuesday) and was centred in the Indonesian Sea 340 kilometres southwest of Cilacap district in southern coast of Central Java, said Anas, an official at the Meteorology and Geophysics Agency in Jakarta. He said the quake occurred at about 33-kilometres beneath the seabed.

Anas, who like many Indonesians uses only one name, said the quake was felt along a wide stretch of the southern Central Java coast, including the cultural city of Yogyakarta, but there were no reports of injuries or damage.

Yogyakarta and nearby regions has been struck by a powerful 7.3-magnitude earthquake on late May 2006, killing more than 5,800 people, injuring thousands of others and destroying and heavily damaging tens of thousands of homes and buildings.

Indonesia, the world's largest archipelago nation, is prone to earthquakes because the country sits atop Asia's so-called "Ring of Fire" where continental plates collide and earthquakes and volcanic eruptions are frequent.

Earthquake shakes Northern California Coast

2007-06-24T22:50:00.000-07:00

The Eureka Reporter - A magnitude 5.1 earthquake rattled parts of the North Coast Sunday at 7:32 p.m. The U.S. Geologic Survey indicated the temblor was located 41 miles northwest of Eureka at a depth of approximately 6.3 miles. There was no indication that the earthquake caused any major damage or injuries. According to the U.S. Geologic Survey’s 24-Hour Aftershock Forecast Map, as of 8 p.m. Sunday, there was a low probability of aftershocks occurring in the region.

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

If you felt this quake and have a story to tell, come on over to our "Quake Stories" board to share and to read other stories about this quake.

Also, be sure to check out the 2007 Earthquake map to see this quake along with other signficant quakes of 2007.

Space Shuttle Brings Sonic Boom

2007-06-22T13:08:00.000-07:00

Many people accross Southern California reported feeling an earthquake shortly before 12:45 pm (west coast time). As it turns out the culprit was not an earthquake, it in fact was the expected sonic boom caused by the return of the Space Shuttle Atlantis.

The shuttle was expected to land in Florida, but due to bad weather the landing was changed to Edwards Air Force Base in the Southern California desert.

The shuttle's path to the base took it over San Diego and Los Angeles before landing smoothly at 12:49 pm.

Small quake shakes Tennessee

2007-06-19T22:44:00.000-07:00

It has been in the works for quite a while: "On the morning of June 19, Tennessee will experience a 7.7 magnitude earthquake inside the New Madrid Seismic Zone near Memphis." What they weren't counting on was a Real quake to strike Tennessee that day.

Tuesday June 19th is the start of one of the states largest emergency response drills. While the main focus of the simulation is the New Madrid Seismic Zone near Memphis, a real earthquake was being felt 170 miles east near the small town of Spencer (about 50 miles North of Chattanooga).

Although the quake was not widely felt, it is a constant reminder that earthquakes can occur at anytime and anyplace and they don't always strike along active fault lines. Tuesdays quake measured 3.3 and occurred at 1:16 PM local time.

If you think that earthquakes never happen in this area, you may be interested in this map which shows all earthquakes in the area (since 1970) with a magnitude of 2.5 or greater.

Here is the map showing the specific location of this quake

Earthquakes Continue in Northern Oregon

2007-06-14T23:26:00.000-07:00

The area between Kent, Oregon and Maupin, Oregon has seen steady quake activity since December of 2006. The quakes have been in a concentrated area about 8 miles ESE of Maupin.

Most of the quakes are small and have not been felt. Quakes of this size usually go unnoticed by most. However, this sequence, now in its seventh month, has raised eyebrows because this kind of consistent quake activity has never been recorded in this location.

On Thursday afternoon, the strongest quake of the sequence was recorded. The 3.9 quake was the strongest in the region since a 4.2 earthquake in November of 1976.

CLICK HERE to view a special report showing all quakes in the area since 1976.

6.8 Earthquake off the Coast of Guatemala

2007-06-13T12:55:00.000-07:00

The following is a release by the United States Geological Survey, National Earthquake Information Center: An earthquake occurred 115 km (70 miles) SSW of GUATEMALA CITY, Guatemala at 1:29 PM MDT, Jun 13, 2007 (1:29 PM local time in Guatemala). The magnitude and location may be revised when additional data and further analysis results are available. No reports of damage or casualties have been received at this time; however, this earthquake may have caused damage due to its location and size.

------------
From the Associated Press
1:43 PM PDT, June 13, 2007

GUATEMALA CITY -- A powerful earthquake shook Guatemala on today, U.S. seismologists said, but there were no immediate reports of damage or injuries in the capital.

The magnitude 6.8 earthquake struck at 1:29 p.m. local time (3:29 p.m. EDT) and was centered 70 miles southwest of Guatemala City off the Pacific coast, according to the U.S. Geological Survey.

Firefighters in Guatemala City said they had no immediate reports of injury or damage.

Radio Sonora reported that houses were damaged along the Pacific coast, with mudslides in several areas. But firefighters in several coastal communities, including Santa Rosa and Escluintla, told The Associated Press they had received no reports of damage.

The quake was felt in neighboring El Salvador, where people ran into the streets in the capital of San Salvador.

Carlos Lopez, a spokesman for the Red Cross in El Salvador, said there were no immediate reports of major damage in that country.

The region is prone to earthquakes. One of Guatemala's most devastating quakes was in 1976 when nearly 23,000 people died.

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

This report will be updated as new information is received

Here are two maps showing the location. The first is a wide view, the second a closer view. (click on image full size image)

Moderate Quake Near Mammoth Lakes

2007-06-12T22:25:00.000-07:00

Aftershocks continue after a 4.6 earthquake shook the Sierra Nevada Mountains in Central California early Tuesday morning. The quake struck just after 12:20am (Pacific Coast time). So far there have been more than 160 aftershocks. Four of the aftershocks have been 3.0 or higher, with the largest being 3.6. The quake was preceeded by a 3.6 foreshock.

Hundreds of people throughout central California and Western Nevada have reported feeling the quake. Some of the stronger aftershocks have been felt by people in the vicinity of the epicenter.

The map here shows the area affected by this series of earthquakes.

This region of the Sierra Nevada's is very familiar with earthquakes. The last strong quake to register above 5.0 was back on May 15, 1999. When the area experienced a 5.6 quake. Even stronger damaging quakes ocurred in 1980.

Explore our Northern California historical Quake maps located on the right side of our website to see quakes in this area over the years.

3.5 Aftershock West of Frazier Park

2007-06-06T02:37:00.000-07:00

Tuesday's 3.5 earthquake was an aftershock to the 3.7 quake which shook the region early Monday morning. Both quakes, along with several smaller aftershocks, are occuring along a segment of the San Andreas fault near the Grapevine.

Anthony Guarino with the Southern California Seismic Network reports that this quake may have been felt in Valencia, Gorman, Castaic, and surrounding communities.

There were no reports of damage or injuries.

This map shows where these quakes occured in relation to the surrounding communties and it's proximity to the San Andreas fault. The orange quake on left is a 3.0 which occured on March 1st of this year.

A closer view of the quake area.

Earthquake in China kills two, injures 200

2007-06-02T20:34:00.000-07:00

Asia-Pacific News

Jun 3, 2007, 2:43 GMT

Beijing - A strong earthquake measuring 6.4 on the Richter scale struck an area of south-western China's Yunnan province early Sunday, destroying houses, killing at least two people and injuring more than 200.

The epicentre of the quake at 5:34 a.m. (2134 GMT Saturday) was at 23.0 degrees north and 101.1 degrees east near Yunnan's Pu'er city, near the border with Myanmar, state media quoted the China Earthquake Administration as saying.

There were reports of damage and casualties in the old town of Pu'er, and by mid-morning local officials had confirmed two people dead and more than 200 injured, 15 of them seriously, the official Xinhua news agency said.

Rescue teams were sent to the affected area to assess the damage and help victims, the agency said.

The US Geological Survey said the quake struck at a depth of 10 kilometres.

4.2 Quake Hits Southern California Desert

2007-06-01T23:03:00.000-07:00

A quake with a preliminary magnitude of 4.2 struck the lower Southern California Desert Friday Night. The quake was widely felt from the deserts to the coast, and even reports that it was felt as far away as Phoenix Arizona, some 250 miles away. Nearly 2,000 felt reports were filed within the first hour of the quake.

If the felt reports are accurate, it's my experience that this quake's magnitude will be upgraded sometime soon.

Click on the picture above to see exactly where this quake struck, along with other quakes in the area that have occurred in 2007.

Small Earthquake Shakes California-Mexico Border

2007-05-31T21:57:00.001-07:00

Associated Press - June 1, 2007 12:04 AM ET

OCOTILLO, Calif. (AP) - A small earthquake has rattled a desert town near the US-Mexico border, but there are no immediate reports of damage or injuries.

A preliminary report from the US Geological Survey says the magnitude-3.9 temblor struck at 7:08 pm. It was centered eight miles southwest of Ocotillo, about ten miles north of the border.

A dispatcher with the Imperial County Sheriff's Department says there are no reports of injuries or damage.

Small Quakes Rattle Lakeview, Oregon

2007-05-30T22:43:00.000-07:00

Two small quakes rattled the California Oregon border near Lakeview, Oregon this evening. The two tremors, registering 3.4 and 3.0 on the richter scale struck right around 7:00 local time on May 30, 2007.

The following two maps show where these quakes occurred. These quakes are preliminary, and their location and magnitudes may change as new data is reviewed.

CLICK HERE to see where this quake struck. (291kb image)

CLICK HERE for an even closer view. (304kb image)

I have prepared a special report showing a map and a list of all quakes in this area, going back to 1982. CLICK HERE to view the special report.

I will revise this report as needed.

Remembering the Cape Mendocino Quakes of 1992

2007-05-30T01:54:00.000-07:00

USGS report

On April 25 at 11:06 a.m. PDT, a major earthquake struck northern California. This magnitude 7.2 earthquake was located about 30 miles (50 km) south-southwest of Eureka. Ninety-five people were injured and considerable damage occurred in southwestern Humboldt County. The preliminary estimate of damage from this earthquake, and two strong aftershocks described below, is 66 million dollars. The observed maximum intensity, VIII, was experienced at Ferndale, Honeydew, Petrolia, Rio Dell, and Scotia. Landslides and rockfalls occurred in the Honeydew-Petrolia area. The quake was felt throughout much of northern California and as far south as San Francisco and southeast to Carson City and Reno, Nevada. It was also felt in many areas of southern Oregon. A tsunami was generated with maximum wave heights (peak-to-trough) of 1.1 meters at Crescent City and 0.2 meters at Point Arena, California, and 0.1 meters on Hawaii.

At 12:42 a.m. PDT on April 26, a magnitude 6.5 earthquake hit the same area causing some additional damage in the Ferndale, Petrolia, and Fortuna areas. A fire caused by a broken gas main destroyed much of the business district of Scotia. The quake was felt throughout much of northern California.

Less than 4 hours after the second quake, at 4:19 a.m. PDT, the same area experienced a third strong quake. This magnitude 6.7 earthquake caused additional damage in the area of Ferndale, Fortuna, and Petrolia. It was also felt thoughout much of northern California and southern Oregon and to the south as far as Salinas, Santa Cruz, and San Francisco. These earthquakes were accompanied by numerous aftershocks. Many of the aftershocks were in the magnitude 4.0 to 4.8 range. Some of them were strongly felt, but they caused very little damage.

3.2 Earthquake Felt in Oklahoma

2007-05-28T02:50:00.000-07:00

UPDATED (5/29/07)

A 3.2 magnitude earthquake struck near Henryetta, Oklahoma shortly after 4:00 PM local time on May 27, 2007. There were no injuries and no damage was reported.

Earthquakes of this size are not all that uncommon in this part of Oklahoma. Historical records indicate that since 1975 at least 21 earthquakes with a magnitude of 3.0 or higher struck within 125 miles of today's quake.

Here is a list of those quakes, starting with the most recent:

Here is a map showing the region and all quakes since 1975

Click on image for larger version

Here is a closer map

Click on image for larger version

Here is an even closer view showing the specific location of this most recent Oklahoma quake

Click on image for larger version

Earthquake Preparedness

2007-05-26T22:27:00.000-07:00

The Los Angeles Fire Department published a great earthquake preparedness guide which they have made available on the Internet.

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

To those of us who live and work in the Greater Los Angeles area, earthquakes are a reality. In order to deal with this situation, earthquake preparedness must become a way of life. In the event of a major earthquake, freeways and surface streets may be impassable and public services could be interrupted or taxed beyond their limits. Therefore, everyone must know how to provide for their own needs for an extended period of time, whether at work, home or on the road.

Our goal in providing this information is to encourage you to prepare for a major earthquake and to maintain that readiness. Part of becoming ready is having the necessary supplies. Earthquakes, in our area, can happen at any time. They are not totally predictable. There are long periods between episodes. This is why it is important to maintain fresh emergency supplies through rotation of older stock into daily use. The quality of life and the potential for survival are greatly increased by being prepared.

William R. Bamattre
Chief Engineer and General Manager
Los Angeles City Fire Department

THE EARTHQUAKE PREPAREDNESS HANDBOOK

Earthquake Reported Near Kīlauea volcano

2007-05-26T21:13:00.000-07:00

Report prepared by the Hawaiian Volcano Observatory:

A magnitude-4.7 earthquake was recorded by the U.S. Geological Survey’s Hawaiian Volcano Observatory on May 24, 2007 at 9:13 a.. H.s.t. It was located beneath the upper east rift zone of Kīlauea volcano, near Puhimau crater, at a depth of 2 km (1 mile). A magnitude 4.1 aftershock occurred at 9:33 a.m. and was located 1.5 km (1 mile) farther downrift beneath Koko‘olau crater. A magnitude-3.9 aftershock occurred at 10:51 a.m. and was located 4 km (2 miles) farther downrift than the magnitude-4.7 at a depth of 1 km (1 miles). These earthquakes are the largest so far in a flurry of earthquake in the upper east and southwest rift zones that started May 12, 2007. The earthquake flurry has not been accompanied by any unusual swelling of the summit or other signs of unusual summit activity. HVO is watching the situation closely.

Since 1998, a few earthquakes with magnitudes greater than 4.0 have occurred at shallow depths beneath the upper east rift zone. Today’s event was the largest in at least the last 50 years.

Big Island Earthquakes are Normal

2007-05-25T17:29:00.000-07:00

from: Hawaii Big Island Volcano Update

We live on volcanos!

But nonetheless, they often make the news so we feel compelled to share any updates. Many times though, earthquakes never make the news outside of the local neighborhoods surrounding Pu`u O`o. It just depends on the volumes of news the big papers are already dealing with. Here’s the scoop on the latest newsworthy earthquake.

“A magnitude-4.7 earthquake occurred at 9:13 am HST at shallow depth beneath the summit caldera and was followed by several aftershocks, the largest of which was a 4.1 at 9:33 am. The earthquake and its aftershocks had no appreciable effect on the continuing Kilauea eruption.

The long story that won’t change daily: Over the past several months, Kilauea caldera has been expanding at a rate of 1.5 cm/month indicating minimal magma storage there; most of the magma supply continues to feed the Pu`u `O`o vent. Pu`u `O`o cone is slowly collapsing as shown by cracks spreading on its south flank and about 1 cm/month subsidence of its north flank.”

Two Quakes Shake Southern California

2007-05-24T01:49:00.001-07:00

May 23, 2007

Parts of Southern California were shaken by two mild earthquakes Wednesday night. Both quakes measured 3.9, and were centered about 2 miles South-Southeast of Devore, California. The first came in at 11:11 PM while the second struck less than five minutes later at 11:15 PM.

Although there have been no reports of injuries or damage, the quakes have been felt all the way the Los Angeles coastline, nearly 80 miles away.

Quakes are not uncommon in this area of the Southland. There have now been five quakes with a magnitude of 3.0 or greater in this general area since the start of the year.

I have created a special page showing the last 20 years of earthquake activity in the immediate Devore area. CLICK HERE to see a list of all quakes (2.5+) between 1987 and 2007.

Remembering the 1999 Bolinas Earthquake

2007-05-13T15:22:00.001-07:00

Written in August 1999 by JCP Seismologists

BOLINAS, CA -- Foundations rocked and rolled as far south as Santa Cruz County -- and shuddered sharply in Bolinas at the epicenter of one of the first significant earthquakes to strike the Bay Area since the Loma Prieta disaster nearly a decade ago. The temblor was felt thoughout much of the North Bay region.

Fortunately, the quake's size was fairly small, at magnitude 5.0. With the exception of a few emptied store shelves and a toppled chimney in the community of Bolinas, 15 miles northwest of San Francisco, there was little damage to speak of.

The shock struck north of the Golden Gate along the San Andreas fault zone near its intersection with the San Gregorio fault, which extends offshore southward from the Bolinas area. Although the San Andreas fault in this area is visited frequently by minor seismic activity, Tuesday's quake was one of the largest to occur along on this stretch of the fault since it ruptured here in the great San Francisco earthquake in 1906.

The U.S. Geological Survey forecast a 1-in-10 chance of strong and possibly damaging aftershocks in the Bolinas area during the week following Tuesday's quake.

Although this earthquake is insignificant in comparison to the disastrous magnitude 7.4 shock in Turkey just the day before, it may prove interesting for local scientists studying the likelihood of future earthquakes in the Bay Area.

The USGS and collaborating scientific agencies are currently updating their estimates of earthquake probability for the region's fault segments, one of which is the San Francisco Peninsula segment. This is a section of the San Andreas fault that extends from Los Gatos northwestward to the Bolinas area, and is immediately north of the Santa Cruz Mountains segment that ruptured in 1989 causing the Bay Area's most recent earthquake disaster.

In its magnitude of 5.0 and its location near the end of a San Andreas fault segment, Tuesday's jolt at Bolinas is not unlike two moderate quakes that closely preceded the Loma Prieta shock. Those events, of magnitude 5.3 and 5.4, occurred near Lake Elsman just south of Los Gatos, about 16 months and 2 months before the earthquake on October 17, 1989.

The Lake Elsman events struck where the northern end of the Santa Cruz Mountains segment and the southern end of the Peninsula segment meet. Their timing and location has led some scientists to regard the Lake Elsman quakes as "preshocks" to the subsequent magnitude 7.1 Loma Prieta rupture -- useful harbingers, if so, had they been recognized as such.

Is the Bolinas quake a preshock of a larger quake to come? On this question the jury hasn't yet had time to convene.

--------------------------
USGS Report

8/17/99 Magnitude 5 earthquake near Bolinas, CA

The magnitude 5 earthquake that occurred on Tuesday, August 17 at 6:06PM local time was located beneath Bolinas Lagoon in Marin County at a depth of about 4.2 miles. It was felt broadly throughout the San Francisco Bay Area and yielded instrumental records of shaking that reflect various ground conditions in the Bay Area.

The earthquake occurred along a stretch of the San Andreas fault that had more than 20 feet of slip in 1906 as indicated by offset fence lines. In contrast, Tuesday's event probably resulted in slip of a few cm on a small patch of fault at depth.

Scientists consider Tuesday's quake to be a small to moderate size event. It would take approximately 4000 such earthquakes to equal the energy released by the 1989 Loma Prieta earthquake or 30,000 such earthquakes to equal the energy released in the magnitude 7.4 earthquake in Turkey which occurred on the same day.

The Bolinas earthquake is interesting to scientists for two reasons:

It occurred in a region that has had only one previous earthquake in the last 30 years of detailed seismic recording.

Information obtained from the earthquake waves indicate an up-down direction of slip not the sideways (or lateral) slip expected for the San Andreas fault.

The first observation was somewhat of a surprise. Much of the 300 mile length of the San Andreas fault that ruptured in 1906 (from San Juan Bautista to Cape Mendocino) is currently aseismic (relatively free of earthquakes) and has been since 1906. Scientists consider the San Andreas fault in Northern California to be in a "locked" part of its earthquake cycle.

The second observation suggests that, in detail, this earthquake probably was not on the San Andreas fault, but rather occurred on a small fault adjacent to the main fault at depth.

Two Earthquakes Rattle North Coast of California

2007-05-11T15:01:00.000-07:00

by Heather Muller , 5/9/2007
The Eureka Reporter

“I thought I was on a boat in the ocean,” said Renee Jacobsen, manager of the Petrolia Store and former chief of the remote town’s volunteer fire department.

The magnitude 5.2 earthquake that struck 39 miles west of Petrolia shortly before 1 a.m. Wednesday “pushed you up like on top of a wave,” she said.

“And then there was the aftershock,” she said, a magnitude 4.5 temblor 17 minutes later and two miles closer to shore.

“That one was more like a sharp jolt.”

According to the U.S. Geological Survey, people reported feeling the initial earthquake as far north as Trinidad and as far south as Victorville — more than 900 miles away.

Brenda Godsey, public information officer for the Humboldt County Sheriff’s Office, said her office received only one earthquake-related inquiry and no reports of injury or damage.

The Office of Emergency Services was not activated, said OES Program Coordinator Dan Larkin.

In situations like this, Larkin said, “there’s nothing we do, because there’s nothing we can do.”

Had the incident been serious, he said, any of a range of responses would have been triggered, possibly including an emergency declaration and the activation of the Emergency Alert System, as well as various local, state and federal emergency response protocols.

Humboldt State University geology professor Lori Dengler said the earthquakes were “of interest and a low level of excitement,” adding that the two events occurred along the Mendocino Fault, which is the region’s single most active fault.

“Since 1980, we’ve had about 150 earthquakes of magnitude 4 or larger along the Mendocino Fault,” she said.

Dengler described the fault as “kind of our Mason-Dixon Line. It really divides the West Coast of the United States into two completely different tectonic areas.”

To the south is the San Andreas Fault with its side-to-side “transform” movement. To the north are the Gorda and the Juan de Fuca plates that converge along the coast and dive down to create the vertical movement characteristic of the Cascadia Subduction Zone.

The Mendocino Fault itself, where Wednesday’s earthquakes occurred, moves horizontally, Dengler said.

“So if you had been standing south of the Mendocino Fault, and if there were no water in the ocean and you could have actually seen what was going on, you would have seen the land north of the fault move maybe half a foot closer to the coast,” she said.

But it could have been worse.

“In the 1906 earthquake, had you been on the San Andreas Fault and looked across to the other side, you would have seen it move more than 20 feet in some places,” she said.

Dengler has long said the North Coast is overdue for a damaging earthquake.

“The point I really like to make is that this is the time to take action to reduce your hazards. It can be something as simple as that huge potted plant on a bookshelf above your bed. Maybe there’s a better place for it. Develop an emergency plan for your family. Make sure your hot water heater is secured to a structural element of your house.

“They’re small things, but they can make a big difference.”

On shaky ground: Significant North Coast earthquakes of the past 30 years

+ June 14, 2005 6:50 p.m.
Magnitude 7.2, centered 97 miles west of Trinidad
Felt lightly but resulted in tsunami warning for the entire West Coast
No reports of injury or damage

+ Feb. 18, 1995 8:03 p.m.
Estimated magnitude 6.5, centered 80 miles west-southwest of Eureka
No reports of injury or significant damage

+ Dec 26, 1994 6:10 a.m.
The Eureka Earthquake
Estimated magnitude 5.4, centered 12 miles west-southwest of Eureka
Minor injuries reported and damages estimated at more than $2.3 million

+ Sept. 1, 1994 8:15 a.m.
The Mendocino Fault Earthquake
Estimated magnitude 6.9, centered approximately 90 miles west of Cape Mendocino
No reports of injury or significant damage

+ April 25, 1992 11:06 a.m.
The Ferndale Earthquake
Magnitude 7.1, centered near Petrolia
Followed by aftershocks of magnitude 6.6 and 6.7 near Cape Mendocino
Damage estimated at $60 million, resulted in federal disaster declaration

+ Sept. 17, 1991 12:29 p.m.
The Honeydew Earthquake
Estimated magnitude 6.1, centered 13 miles south-southeast of Cape Mendocino
More than 60 percent of Honeydew residents reported structural damage

+ Nov. 8, 1980 2:27 a.m.
The Trinidad Earthquake
Magnitude 7.1, centered 30 miles west of Trinidad
Freeway overpass south of Eureka collapsed
Regional damages estimated at $1.75 million

Source: Humboldt State University Geology Department’s Humboldt Earthquake Education Center

Remembering the 1984 Morgan Hill Earthquake

2007-04-12T22:04:00.000-07:00

On April 24, 1984 at 1:15 p.m. PST, a 6.2 magnitude earthquake occurred on the Calaveras fault to the east of San Jose, California. This earthquake was felt over an area of approximately 120,000 km2 in California and western Nevada. The area of moderate damage ($8 million) extended southward from the epicenter rather than centering on the epicenter. This pattern indicates that the Morgan Hill earthquake may have been a double event with the second event being located about 17 km southeast of the main shock.

In Santa Clara County, where most of the damage occurred, more than 550 structures incurred minor damage. Major structural damage was mainly confined to a very small area on two streets of the Jackson Oaks subdivision located east of Morgan Hill (population 19,000). Five houses were condemned; two of these had fallen off their concrete foundations and suffered partial collapse. Several masonry buildings on Main Street in Morgan Hill were damaged and later condemned. Well-engineered industrial buildings and residential structures sustained only minor damage, but many mobile homes fell off their supports causing considerable damage to the furnishings inside. There were many reports of fires resulting from the quake. Minor damage also occurred at San Martin and Coyote. Twenty-seven people were injured.

Small Quake Hits off the Coast of Northern California

2007-04-08T22:09:00.000-07:00

Associated Press - Petrolia, CA (April 6, 2007)

A small quake struck off the coast of Humboldt County on Thursday afternoon (4/5/07), but there were no immediate reports of injuries or damages.

The magnitude-4.1 earthquake struck at 3:54 p.m. and was centered about 40 miles southwest of Eureka and 206 miles northwest of Sacramento, according to the U.S. Geological Survey

There were no immediate reports of damage or injuries, according to a spokeswoman for the Humboldt County Sheriff's Department.

Magnitude 6.7 Felt Throughout Hawaii

2006-10-16T22:25:00.000-07:00

The following is a release by the United States Geological Survey, National Earthquake Information Center: A strong earthquake occurred about 10 miles (15 km) north-northwest of Kailua Kona or 65 miles (100 km) west of Hilo, Hawai`i at 11:07 AM MDT, Oct 15, 2006 (7:07 AM HST in Hawaii). The magnitude and location may be revised when additional data and further analysis results are available.

Numerous people suffered minor injuries, many buildings damaged and landslides blocked roads on Hawaii. Power outages occurred throughout the Hawaiian Islands.

The Island of Hawaii is the youngest island in a chain of volcanoes that stretch about 3500 miles across the north Pacific Ocean. The island chain results from a stationary hot spot that originates deep beneath the crust. The ocean crust and lithosphere above the hot spot move to the northwest as a result of plate tectonics. During the process new island volcanoes are formed and older volcanoes are carried away from the hot spot source, erode, and eventually subside beneath sea level. The vast majority of earthquakes in Hawaii are related to volcanic activity. Some occur before or during an eruption and likely result from underground movement of magma. Others, like this recent earthquake, result from stresses that build in the Earth’s crust as the volcano grows. Earthquakes on the volcanic Island of Hawaii are not rare. The largest on record was the magnitude 7.9 1868 earthquake which triggered a tsunami that drowned 46 people and spawned numerous landslides that resulted in 31 deaths. In the vicinity of the recent earthquake, a magnitude 6.9 tremor struck on August 21st 1951 that damaged scores of homes on the Kona coast and triggered numerous damaging landslides.

Small Earthquake Rattles Southern Island

2006-07-09T22:46:00.000-07:00

By Rebecca Whitney
The Pictorial
Jul 08 2006

VICTORIA, BC - A minor earthquake on Tuesday had some people in the Cowichan Valley rumbling in their boots.

Pacific Geoscience Centre reported the quake, with a magnitude of 3.7, was centred in the Strait of Juan de Fuca 20 kilometres off the coast of Victoria.

Earthquakes on the scale of Tuesday’s shake do not generally cause damage — and in this instance there was no damage reported — although some Victoria residence reported incidences of things falling from shelves.

“You don’t start to get damage until you get to a 5 or 5.5 and even then only in poorly built structures,” said Natural Resources Canada earthquake seismologist Taimi Mulder.

“A 3.7 would feel like a truck slamming into your house — a real short, sharp jerk,” said Mulder.

As you move further from the epicenter of the quake, the frequency of the waves lengthen and therefore the quake is felt as more of a swaying of the ground.

People as far up Island as Shawnigan Lake and Cobble Hill reported feeling the earth move under their feet, but only very slightly.

According to Mulder there were three reports written in from the south Cowichan region stating the quake felt like a “strong gust of wind hitting the house” and an audible “vibration” that didn’t cause any movement.

Earthquakes of this magnitude occur a couple of times a year in southwestern British Columbia, and Mulder says “every couple of months an earthquake will occur that is strong enough to be felt.”

Mulder asks Vancouver Island residents to report to Natural Resources Canada if they feel an earthquake because people’s experiences are valuable tools in measuring and analyzing earthquakes.

“People’s experiences provide us with really valuable local information, said Mulder.

If you get shaken by a quake log onto www.earthquakescanada.ca and click on Did You Feel it.

4.7 Quake Rattles South Bay Area

2006-06-15T19:05:00.000-07:00

SAN MARTIN, June 15, 2006 - A magnitude 4.7 earthquake struck the south San Francisco Bay area early Thursday, but there were no reports of injuries or damage, authorities said.

The quake struck at 5:24 a.m. PDT about 6 miles east of San Martin, a town of 4,200 people in a rural part of southern Santa Clara County, and was followed by three smaller quakes, according to the U.S. Geological Survey.
The quake could be felt in San Francisco, about 70 miles north of the epicenter.

No one was hurt and there were no reports of damage, according to the Santa Clara County sheriff's department and police in Gilroy, about 8 miles from where the quake struck.

Major Quake Shakes Southern Africa

2006-02-22T16:39:00.000-08:00

Associated Press

Feb. 22 - An earthquake with an estimated magnitude of 7.5 struck Mozambique, the U.S. Geological Survey said Wednesday. There was no immediate word on injuries or damages.

The quake hit at 12:19 a.m. Thursday local time. Its epicenter was 140 miles southwest of Beira, on Mozambique's Indian Ocean coast, USGS spokeswoman Clarice Ransom said. She said the initial reading had been 6.9 but was adjusted upward.

The earthquake was felt as far away as Durban, South Africa, and Harare, Zimbabwe.

A newspaper editor in Maputo said he was in the 11th floor of an apartment building that was rocked by the quake.

"It shook a lot. We could feel it very strongly," Fernando Velosa, editor of Jornal de Mocambique, told Lisbon radio station TSF. Portugal is the former colonial ruler of the African nation.

The quake was shallow, which increases the potential for damage, said Dale Grant, a geophysics with the USGS National Earthquake Information Center in Golden, Colo., which is a clearinghouse for temblors worldwide.

"It was felt very widely in in the epicentral area, though it's not a very heavily populated area," Grant said. "There is certain to be damage, but so far, we've had absolutely no word of damage."

WIDE MAP

CLOSE MAP

3.6 Earthquake Felt Across Northwest

2006-02-02T21:01:00.000-08:00

KIROTV.com

EVERETT, Wash. -- Residents near Everett and surrounding areas felt a 3.6 magnitude earthquake Thursday evening just before 6 p.m.

The University of Washington, Department of Earth and Space Sciences reported the earthquake at 5:47 p.m., 9 miles west of Everett with a depth of 19 miles.

That puts the center of the earthquake on the south end of Whidbey Island.

People who felt the earthquake called the KIRO 7 newsroom from Camano Island, Everett, Queen Anne Hill, Arlington, and Port Ludlow.

There were no reports of damage or injuries.

Minor quake reported in Portland

2006-01-28T22:58:00.000-08:00

Associated Press

A minor earthquake was reported in Portland Saturday evening. There were no immediate reports of injury of damage.

The U.S. National Earthquake Information Center in Golden, Colo., put the intensity at 2.8, near the lower levels normally felt by humans. An intensity of 3 was registered on seismographs at some other points.

The epicenter was listed as being in close-in northeast Portland about 10 miles deep.

Geophysicist Dale Grant at the National Earthquake Information Center in Golden said a quake of that magnitude may be felt "but it's not going to do damage of any significance."

Nearly 17,000 earthquakes of magnitude 1 to 6 have been recorded in Oregon and Washington since 1970. Between 15 and 20 quakes a year are strong enough to be felt in the Northwest. Those are usually magnitude 3 to 4, according to the Oregon Department of Geology and Mineral Industries.

Small earthquake shakes rural area outside Morgan Hill

2006-01-26T21:20:00.000-08:00

associated press

MORGAN HILL – An earthquake with a preliminary-magnitude of 3.7 struck a rural area south of the San Francisco Bay area on Wednesday morning, according to the U.S. Geological Survey.

The quake, which struck just before 7:30 a.m., was centered in an area 20 miles northeast of Morgan Hill and 23 miles east of San Jose in Santa Clara County, the USGS. said.

Neither the Santa Clara County Sheriff's Department nor the Morgan Hill Police Department received any immediate reports of injuries or damage.

Scientist says earthquake shows bigger one could be on the way

2006-01-17T21:51:00.000-08:00

THE NEWS TRIBUNE
Published: January 17th, 2006 02:30 AM

An earthquake described as “a miniature version” of the Nisqually quake that rocked Seattle nearly five years ago was a wake-up call in more ways than one, a scientist said.
Many residents in and around the British Columbia provincial capital and the Gulf Islands and a few on the mainland were jolted awake by the 3.9 magnitude quake at 4:29 a.m. Sunday, said John Cassidy, a seismologist with Natural Resources Canada.

About 200 people submitted reports on the agency’s Web site, most saying they felt the shaking for several seconds, Cassidy said.

There was no significant damage, just two or three reports of a few items being knocked from shelves, but the quake should be a reminder of the possibility of much bigger and more dangerous ones, he said.

“It’s been fairly quiet in terms of felt earthquakes for a couple of years here in Victoria, and that’s a bit unusual,” he said. “We generally have one or two small earthquakes a year that are felt on southern Vancouver Island.”

The quake was centered about 27 miles beneath Finlayson Arm near Bamberton, about 15 miles north of Victoria, and occurred within the Juan de Fuca plate, which is slipping beneath the North American plate of the Earth’s crust at the rate of about 11/2 to 2 inches a year, Cassidy said.

The Associated Press

Minor Quake Shakes up Eastern Santa Clara County

2006-01-16T00:48:00.000-08:00

Written for the web by Bob Montgomery, Internet News Producer

Residents of eastern Santa Clara County got an early wakeup call this morning when an earthquake rumbled through the region.

The temblor, which struck at 2:42 a.m., had a magnitude of 3.6. It was centered 21 miles east of San Jose, near the border between Santa Clara and Stanislaus counties. The quake occurred at a depth of 3.2 miles.

The shaker was strong enough to wake up some residents of the area, but did not cause any significant damage or injuries. It was felt in a number of South Bay communities, including Morgan Hill, Alum Rock and parts of San Jose.

6.9 Magnitude Earthquake Rattles Greece

2006-01-08T17:10:00.000-08:00

By PARIS AYIOMAMITIS

ATHENS, Greece - A powerful earthquake shook Greece on Sunday and was felt as far away as the Middle East and Italy. Minor damage was reported in southern Greece, and authorities on the island of Crete said three people were slightly injured.

No tsunami warnings were issued.

The Athens Geodynamic Institute said the epicenter of the 6.9-magnitude quake was located beneath the seabed about 125 miles south of Athens and 12 miles east of the island of Kithira in the Sea of Crete.

"It was a very powerful quake which shook all of Greece. There have been dozens of aftershocks," institute head Giorgos Stavrakakis said. "The quake occurred deep undersea and that's what saved us."

Stavrakakis said he did not expect any serious aftershocks.

The earthquake, which lasted for several seconds, occurred at 1:34 p.m. and was felt as far away as Cairo, Egypt, about 745 miles southeast of the epicenter.

The quake also was felt across southern Italy but there were no reports of damage or injuries, Italian news reports said.

Clarice Nassif Ransom, a U.S. Geological Survey spokeswoman in Washington, said scientists project that as many as 6 million people may have felt the earthquake.

Police on Crete, just south of Kithira, said three people suffered minor injuries.

On Kithira, regional governor Yiannis Mihas said 50 homes in the village of Mitata were damaged, and the village church was close to collapse.

Small Quake Jolts Santa Cruz County

2006-01-05T20:20:00.000-08:00

BEN LOMOND — Residents across Santa Cruz County were shaken awake this morning by a small earthquake that hit about 6:05 a.m.

No injuries or damages were reported. The 3.1 magnitude temblor struck about 2 miles from Ben Lomond, and originated 6.3 miles beneath the earth’s surface, according to the U.S. Geological Survey.

“It woke people up, and we got about 8 or 9 calls asking about damage,” Sheriff’s Lt. Steve Hartness said, adding that it felt like a truck had hit his house. “There was nothing to report.”

Many people, such as Karen Randall of Ben Lomond, weren’t sure the quick jolt was actually an earthquake.

“We all kind of wondered what it was,” said Randall, who had already arrived to work at Ben Lomond Market on Highway 9 when the quake struck. “I just heard a noise. It was kind of weird.”

Strong Quake Strikes Baja California

2006-01-04T01:09:00.000-08:00

A strong earthquake with a preliminary magnitude of 6.7 has hit the Gulf of California, about 435 miles south of San Diego.

The quake struck at 12:32 AM (1/4/06) Pacific Coast time and was preceded by a series of at least three quakes that registered over 4.0 on the Richter scale.

It is still too soon for reports of damage or injuries, but the quake did occur within 75 miles of some populated areas.

01:40AM (1/4/05)

The following is a release by the United States Geological Survey, National Earthquake Information Center: A strong earthquake occurred 90 km (55 miles) NNE of Santa Rosalia, Baja Calif. Sur, Mexico and 1620 km (1010 miles) NW of MEXICO CITY, D.F., Mexico at 1:32 AM MST, Jan 4, 2006 (1:32 AM MST in Mexico). The magnitude and location may be revised when additional data and further analysis results are available. There have been no reports of damage.

7.3 Earthquake Hits South Sandwich Islands

2006-01-02T01:26:00.000-08:00

The following is a release by the United States Geological Survey, National Earthquake Information Center:

A major earthquake occurred EAST OF THE SOUTH SANDWICH ISLANDS, about 345 Km (215 miles) SE of Bristol Island, South Sandwich Islands, or about 3945 km (2450 mi) south-southeast of Buenos Aires, Argentina at 11:10 PM MST, Jan 1, 2006 (Jan 02 at 5:10 AM local time in South Atlantic Ocean).

The magnitude and location may be revised when additional data and further analysis results are available. This earthquake is located in a remote area and no damage or casualties are expected

3.9 magnitude temblor hits near Kettleman City

2006-01-02T01:22:00.000-08:00

A 3.9-magnitude earthquake hit near Kettleman City on Saturday afternoon (12/31/05).

The quake struck at 1:30 p.m. about eight miles southeast of Kettleman City, according to the U.S. Geological Survey's Web site.

There were no reports of damage or injuries, said senior deputy Jesse Ferrell with the Kings County Sheriff's Department.

Small Earthquakes Rattle Santa Monica

2005-10-22T22:18:00.000-07:00

Two small quakes were felt through the west Los Angeles area on Saturday. The first quake struck at at 1:18 in the afternoon local time and registered 3.1 on the richter scale. The second quake was felt at 8:42 in the evening and has a preliminary magnitude of 3.0.

Quakes of this size are not expected to cause any damage.

The quakes were centered about 7 miles below the surface of Santa Monica. Specific coordinates put the epicenters near Santa Monica airport.

Click on the map to see a detailed picture of the area where these quakes were centered.

SPECIAL REPORT: 7.7 Pakistan Earthquake

2005-10-10T01:07:00.000-07:00

I have created a special map showing a detailed location of this killer 7.7 earthquake and it's 6.2 aftershock.

We know the earthquake has been felt for many hundreds of miles, however, the most tragic reports are coming out of the small villages near the epicenter.

This map shows the distances between nearby small towns and the 7.7 earthquake.

CLICK HERE TO SEE THE MAP

Palm Springs Quake Falsely Reported

2005-09-28T02:39:00.000-07:00

The Associated Press released a news story stating that a 3.2 magnitude earthquake occurred 13 miles north of Palm Springs on Sunday September 25. The fact of the matter is that no such quake occurred.

What did happen was what is called a "teleseism". Teleseisms are seismic waves caused by distant earthquakes. In this case, the teleseisms were caused by the 7.5 earthquake in Peru, which occurred several minutes before the teleseisms arrived in Southern California.

The Southern California Seismic Network's automatic earthquake detection system mistakenly thought the waves were those of a small local quake. Those who have pagers connected to the SCSN (Caltech/USGS employees, first responders, utility companies, and media) received a page (or automatic email) for a M3.2 quake near Desert Hot Springs at that time. As it turns out, the SCSN Duty Seismologist removed the event from the Simpson Map (the California earthquake map).

All earthquakes that occur are reviewed by a human. The automatic detection system is not perfect and sometimes mis-reports earthquakes.

Associated Press writers released this story without confirming that a quake actually occurred.

The quake in question was removed from the system within just a few minutes. Yet the news story lives on. Still, no reports of damage or injuries....

Tehachapi Quake Updated

2005-09-28T02:29:00.000-07:00

The earthquake that occurred 18 miles North of Tehachapi, California on September 24th has been upgraded from a magnitude of 3.5 to 3.6.

This is not a significant change. The adjustment came after several standard reviews. Many adjustments to magnitude, depth, location and time of occurrence, are made to all earthquakes. Reviews and adjustments can go on for days, weeks and sometimes months, depending on the size of the quake.

This earthquakes depth was also adjusted from 6.3km to 6.0km.

4.7 Earthquake Shakes the Mettler Area

2005-09-23T22:35:00.000-07:00

A moderate 4.7 earthquake shook the Mettler California area on September 22. The quake was felt as far away as Orange County to the South and Fresno to the North. The quake caused minor merchandise damage to some local shops, but no injuries were reported.

A 3.4 foreshock preceded the 4.7 mainshock by forty-four seconds. A robust aftershock sequence followed. Eight aftershocks above 3.0 were recorded within 14 hours.

This particular area is known to have earthquakes on occasion. Earlier this year A 5.2 earthquake and a 4.1 quake struck an area about 10 miles west of this current sequence.

In 1952 the Kern County 7.5 Quake was centered less than five miles from the location of this quake.

Small Quake Rattles Santa Cruz Area

2005-09-18T02:22:00.000-07:00

SEPTEMBER 18, 2005

An earthquake with a preliminary magnitude of 3.1 rattled a section of California south of San Francisco. The quake was located between Santa Cruz and Menlo Park near the small community of Boulder Creek. The quake struck just after midnight.

Although the quake was small it was felt by many people. Within two hours over one thousand people have reported feeling the quake. Reports have come in from as far north as San Francisco and as far south as Santa Cruz.

A quake of this size is not expected to cause major damage or injuries.

Strongest shaking was felt around the Boulder Creek area. One local resident was quoted as saying "set things to swinging and rattled with windows/glasses."

The deadly 7.0 Loma Prieta earthquake struck this region during the evening of October 17, 1989. That quake was centered 9 miles northeast of Santa Cruz, or 18 miles southeast of this recent quake.

The map below (click for full size) shows where this quake and it's first five small aftershocks occurred in relation to boulder Creek.

Slow Seismic Slip Event Underway in Pacific Northwest

2005-09-15T00:13:00.000-07:00

An important seismic event imperceptible to humans has begun in the Pacific Northwest as predicted, according to the government agency Geological Survey of Canada.

The chance of a major earthquake is 30 times higher now for a roughly two-week period, but the odds are still remote, scientists say

continue...

SPECIAL REPORT: Fontana, CA

2005-09-07T00:57:00.000-07:00

Late in the evening of September 6, 2005 we have seen a small swarm of earthquakes developing around the Fontana area.

1.3 2005/09/06 11:52 PM ( 2 mi) NW of Loma Linda, CA
1.0 2005/09/06 11:03 PM ( 4 mi) NNE of Fontana, CA
1.2 2005/09/06 10:56 PM ( 4 mi) NNW of Rialto, CA
1.2 2005/09/06 10:20 PM ( 2 mi) WSW of Loma Linda, CA
2.0 2005/09/06 10:09 PM ( 4 mi) NNE of Fontana, CA
1.0 2005/09/06 10:08 PM ( 4 mi) NW of Rialto, CA
1.2 2005/09/06 9:53 PM ( 4 mi) NW of Rialto, CA
1.4 2005/09/06 9:39 PM ( 4 mi) NNE of Fontana, CA

Do these small quakes mean a larger one is on the way? I did some research and I will present my findings and let you decide for yourself whether these are foreshocks are just another small swarm.

I searched past earthquakes which have occurred within 10km of this current activity.

Since 1950 there have been 17 earthquakes of 3.5 or greater. Seven of these had at least one foreshock.

Here is a map showing the specific location we are talking about. Quakes shown on the map come from the list below:

Mainshocks are listed in BOLD

3.9 5/15/1955 5:03 PM

4.1 6/28/1960 8:00 PM

3.8 8/21/1960 11:07 PM

3.7 2/25/1965 11:21 AM

3.7 9/2/1966 11:06 AM

3.6 10/14/1967 12:36 AM

3.5 3/17/1975 12:13 AM

1.9 1/7/1983 5:01 PM
2.7 1/8/1983 6:29 AM
4.0 1/8/1983 7:19 AM

1.6 2/18/1987 12:52 AM
1.4 2/18/1987 4:03 AM
1.7 2/21/1987 5:19 AM
4.0 2/21/1987 11:15 PM

1.2 10/11/1997 2:26 AM
1.5 10/11/1997 11:16 AM
1.1 10/13/1997 11:51 AM
3.9 10/14/1997 10:31 PM

1.4 11/1/1997 11:32 AM
3.6 11/4/1997 2:36 PM

0.9 1/29/1999 2:53 AM
3.6 1/30/1999 11:24 PM

3.5 4/9/2000 6:52 AM

3.7 7/25/2002 12:43 AM

1.4 7/26/2004 6:32 AM
3.8 7/28/2004 8:19 PM

1.6 1/2/2005 12:19 PM
1.4 1/2/2005 8:34 PM
1.1 1/2/2005 9:51 PM
1.1 1/2/2005 10:01 PM
1.5 1/2/2005 10:53 PM
2.7 1/4/2005 8:21 AM
1.6 1/4/2005 8:21 AM
1.8 1/4/2005 8:49 AM
3.1 1/4/2005 8:49 AM
1.1 1/4/2005 9:31 AM
1.3 1/4/2005 8:25 PM
1.6 1/5/2005 2:12 PM
1.6 1/5/2005 2:26 PM
2.5 1/6/2005 12:11 PM
3.6 1/6/2005 12:11 PM
2.5 1/6/2005 12:32 PM
3.3 1/6/2005 2:22 PM
4.4 1/6/2005 2:35 PM

Steps to Building A Personal Emergency Plan

2005-09-06T16:49:00.000-07:00

Before you begin, take a few moments to consider the possible emergency situations or potential disasters you could face. These are situations and events that could impact you, your family or your neighborhood or community. Talk to your family members to get their views and assistance in building an action plan you and your family can follow to help reduce the possible effects of any emergency or disaster. You may want to consider helping your neighbours do the same, especially those who are elderly or disabled.

The following steps will help you develop a personal or family emergency plan:
MORE....

2004 West Coast Earthquake Maps

2005-09-06T01:57:00.000-07:00

I have uploaded the 2004 earthquake maps. You can access them using the menu on the right sidebar.

I have decided to put the map and the list on the same page. The list appears below the map. Hopefully this will make it easier to view the data.

If you have any problems viewing or accessing the maps please leave a comment or send me an e-mail.

Obsidian Butte: Swarm Update

2005-09-05T02:45:00.000-07:00

UPDATED: 9/5/05 - 3:00 AM

NEXT UPDATE: 9/10/05 (unless there is a significant increase in activity)

NOTE: This report focuses on a very small radius (20km) around Obsidian Butte and does not include the entire Brawley Seismic Zone.

CURRENT SWARM STATS:
Total Quakes (8/25 - 9/5 2:15am) = 626

dates
8/25 = 1 quake
8/26 = 0 quakes
8/27 = 0 quakes
8/28 = 8 quakes
8/29 = 15 quakes
8/30 = 2 quakes
8/31 = 220 quakes
9/1 = 251 quakes
9/2 = 80 quakes
9/3 = 34 quakes
9/4 = 11 quakes
9/5 = 4 quakes (preliminary)
These quake counts are likely to change with time as USGS officials manually review seismographs.

magnitudes
0.1 - 0.9 = 2 quakes
1.0 - 1.9 = 426 quakes
2.0 - 2.9 = 165 quakes
3.0 - 3.9 = 25 quakes
4.0 - 4.9 = 7 quakes
5.0+ = 1 quake

Obsidian Butte is one of several areas in California known for its earthquake swarms. Unlike The Geysers in Northern California and Coso Junction in Central California, Southern California's Obsidian Butte is sporadic and inconsistent with its swarming. While the other swarm areas rarely see days without quakes, Obsidian Butte can go months without registering a single quake. But when they come, they come in a big way. However, when the quakes do come, they come in volume and not strength.

Obsidian Butte is not known for producing large destructive quakes. Obsidian Butte has seen thousands and thousands of quakes over the years (nearly 10,000 since 1960). However, since 1900 there has only been a handful of quakes that have been stronger than a 5.0. The largest being a 5.8 in 1981. That was also the last time a 5.0 or larger quake was centered in the vicinity of Obsidian Butte.

HERE is a map
showing all 5.0+ quakes that have occurred near the Salton Sea since 1900. On the map you will notice that there are just a few quakes in the immediate area of Obsidian Butte. All Obsidian Butte swarms occur tight against the South-East shoreline of the Salton Sea.

This swarm is following a classic pattern. Reviewing past swarm data shows that this one is making a run to be one of the strongest in many years.

we have seen some impressive swarms since 1960. Here is a list of the most active months (minimum of 50 quakes):

APR 1981: 1250 quakes
SEP 2005: 380 quakes (preliminary)
AUG 2005: 285 quakes (preliminary)
MAR 1989: 248 quakes
NOV 1976: 239 quakes
MAY 1981: 184 quakes
JUN 1979: 169 quakes
NOV 1987: 162 quakes
JUL 1987: 152 quakes
MAY 1983: 130 quakes
OCT 1999: 112 quakes
MAY 1996: 107 quakes
OCT 1979: 105 quakes
JAN 1998: 94 quakes
APR 2003: 88 quakes
MAY 2000: 86 quakes
JUN 2000: 83 quakes
MAR 2004: 77 quakes
JUL 1983: 76 quakes
AUG 1996: 75 quakes
FEB 1989: 69 quakes
DEC 1997: 67 quakes
DEC 1988: 58 quakes
AUG 1986: 56 quakes
OCT 1988: 54 quakes
FEB 2002: 53 quakes
OCT 1995: 51 quakes
JUL 1992: 50 quakes
SEP 2003: 50 quakes

April 26, 1981 was most likely the most active day for swarm quakes at Obsidian Butte. 609 earthquakes were recorded on that day. This day also saw the strongest swarm related earthquake which was a 5.8.

Interestingly there has only been three, maybe four quakes above 5.0 at Obsidian Butte since 1900. We have already talked about the largest, a 5.8 on April 26, 1981. The others were a 5.1 on November 4, 1976 and a 5.5 on July 29, 1950.

The 5.1 in 1976 was also in the middle of a swarm. That particular swarm started at 04:57 with a 2.6 quake. The 5.1 occurred at 10:41 and was the 42nd quake to occur in the sequence. This 1976 swarm died out by the end of November with a total quake count of over 200.

Here is a list of all Obsidian Butte quakes with a magnitude of 4.0 or higher. There really isn't very many considering Obsidian Butte has been the host to nearly 10,000 earthquakes since 1960.

5.8 4/26/81
5.1 9/1/2005
5.1 11/4/76
4.7 10/16/99
4.6 8/31/2005
4.6 3/6/89
4.5 9/1/2005
4.5 8/31/2005
4.5 10/16/99
4.5 8/31/2005
4.4 8/31/2005
4.4 7/13/83
4.4 11/4/76
4.3 8/31/2005
4.2 11/4/76
4.2 11/4/76
4.2 10/27/63
4.2 10/19/88
4.1 8/31/2005
4.1 6/13/79
4.1 11/4/76
4.1 11/4/76
4.1 11/4/76
4.1 11/4/76
4.0 12/31/97
4.0 4/26/76

CURRENT SWARM REPORT
This report will be updated periodically to reflect new quakes. The map below (click for larger view) shows only quakes from this current swarm. These quakes will not be added to the main maps and lists until their magnitudes and locations have been reviewed and updated.

CURRENT OBSIDIAN QUAKES OF 3.0 AND GREATER
click here to see all quakes

3.7 9/5/2005 1:53 AM 1E Obsidian Butte, CA
3.0 9/3/2005 4:17 AM 1ENE Obsidian Butte, CA
3.4 9/1/2005 11:44 PM 1ENE Obsidian Butte, CA
3.3 9/1/2005 8:55 PM 3SSW Obsidian Butte, CA
3.3 9/1/2005 8:54 PM 2SSW Obsidian Butte, CA
3.1 9/1/2005 8:50 PM 1SW Obsidian Butte, CA
3.2 9/1/2005 8:46 PM 2SW Obsidian Butte, CA
3.7 9/1/2005 7:46 PM 1SSW Obsidian Butte, CA
3.0 9/1/2005 6:38 PM 1SSW Obsidian Butte, CA
3.8 9/1/2005 6:30 PM 2WSW Obsidian Butte, CA
5.1 9/1/2005 6:27 PM 1S Obsidian Butte, CA
4.5 9/1/2005 6:27 PM 0NE Obsidian Butte, CA
3.0 9/1/2005 6:23 PM 2E Obsidian Butte, CA
3.2 9/1/2005 7:06 AM 3NE Obsidian Butte, CA
4.4 9/1/2005 6:50 AM 1NNE Obsidian Butte, CA
3.6 9/1/2005 6:50 AM 0E Obsidian Butte, CA
3.5 9/1/2005 6:48 AM 1E Obsidian Butte, CA
3.1 9/1/2005 1:24 AM 1E Obsidian Butte, CA
3.1 8/31/2005 9:15 PM 1ENE Obsidian Butte, CA
4.5 8/31/2005 4:32 PM 3ENE Obsidian Butte, CA
3.4 8/31/2005 4:29 PM 2E Obsidian Butte, CA
4.3 8/31/2005 4:27 PM 3ENE Obsidian Butte, CA
4.1 8/31/2005 4:07 PM 1ENE Obsidian Butte, CA
3.1 8/31/2005 3:59 PM 0ESE Obsidian Butte, CA
3.2 8/31/2005 3:54 PM 1SSE Obsidian Butte, CA
4.5 8/31/2005 3:50 PM 2E Obsidian Butte, CA
4.6 8/31/2005 3:47 PM 1SSE Obsidian Butte, CA
3.5 8/31/2005 3:45 PM 1E Obsidian Butte, CA
3.1 8/31/2005 3:17 PM 1E Obsidian Butte, CA
3.1 8/31/2005 2:49 PM 1NE Obsidian Butte, CA
3.4 8/31/2005 9:18 AM 3ENE Obsidian Butte, CA
3.7 8/31/2005 8:35 AM 2NE Obsidian Butte, CA
3.1 8/29/2005 12:39 AM 4NE Obsidian Butte, CA

Here are some links to articles about the swarm:
Is there a relationship between the Salton Sea earthquake swarm near Obsidian Butte and the hurricane Katrina? (conscious junkyard)

Kate Hutton Earthquake commentary (SCSN)

SCSN Special Report (SCSN)

3.8 Quake Rattles San Diego - Video Footage

2005-09-03T00:07:00.000-07:00

A 3.8 earthquake centered along the California and Mexico border just south of San Diego has been felt throughout San Diego county. The quake struck at 11:53 PM on September 2, 2005.

I was able to capture this quake on video. The video clip is not very exciting and not much to see. But I am excited because it has already answered several questions I had. It will help in my research.

This is the first quake to be captured using my new "Klesko Cam".

Let me take a moment to explain what we are seeing on the video clip. First of all, the quake was heard before it was felt. As the video begins you will hear that I am watching the baseball game. I heard a loud roaring sound coming from outside. I stopped the TV. This is when the sound of the ball game stops. If you have a good sound system with a sub woofer you should be able to hear the deep roaring sound. At the same time you can see Ryan Klesko's head vibrate ever so slightly. Five seconds later the S waves (shear waves) arrived and you can see and hear the small jolt.

The loud whistling/ringing you hear is the quake alarm sounding. The quake alarm is a very sensitive device which detects seismic waves. This quake was rather small and the P waves (which was the loud roaring sound and slight vibration) were too slight to activate the alarm. The slower moving and more destructive S waves arrived five seconds later, when we heard the quake alarm.

ABOUT KLESKO CAM
Klesko Cam is designed to record a visual and audio record of earthquakes. The scene is a hodgepodge of household junk. In theory here is what we should be able to see:

First, we should hear the quake alarm start sounding. At the same time we may see Ryan Klesko's head start vibrating. The strength of the P wave vibration will be determined by the strength of the quake.

Next, we wait for the arrival of the S waves. The "S" or Shear Waves travel slower than the P waves. The timeframe between the "P" waves and the "S" waves are determined by how far away we are from the epicenter of the quake.

When the S waves arrives we should see Ryan Klesko start nodding or shaking his head (depending on the direction of the quake from our location).

If the quake is strong enough, we should see the dominoes start tumbling over. I only have one domino right now, but I'm saving up for more. I plan on setting up the dominoes in such a way that it can be determined which direction the quake came from by observing which dominoes fell and how they fell.

If the quake is even stronger, we will see the collapse of the "Diet Dr. Pepper Pyramid".

If the quake is even stronger you may see the camera start to tip over as you hear me in the background screaming and running around in a panic.

FAQ: Interactive Maps

2005-08-26T23:50:00.000-07:00

This weblog is designed as a research tool for people interested in current and past earthquake activity. The west coast of the United States is our main focus. However, we do special reports for significant earthquakes around the world.

OUR MAPS- We use Google Earth for our primary maps. Our earthquake maps are divided into three west coast regions:

Southern California (31.5 37.0, -129.5 -114.0)
Northern California(36.5 42.4, -129.5 -116.9)
Oregon & Washington (41.9 49.2, -129.5 -115.7)

Watch for maps and lists in our special reports as well. Our special reports feature maps of significant earthquake events from all over the country and other parts of the world.

Earthquakes are plotted on these maps using a custom program created specifically for this project.

DATA
Earthquake data comes from various sources. The ANSS Composite Earthquake Catalog, is used for all regions. Southern California also uses data from the Southern California Earthquake Data Center. Northern California also uses data from the Northern California Earthquake Data Center.

The ANSS catalog uses composite data from several sources. To create a more complete report, we supplement this data with data from SCEDC and NCEDC. It's common to have the same earthquake listed twice with differing details. Our software eliminates these duplicates and uses the listing with the largest magnitude.

INTERACTIVITY
Our maps are interactive. You can click on larger quakes (usually 5.0+) to see a closer map of that specific area. These special maps are produced only for larger quakes that occur over land within the boundaries of the United States.

COLORS & SIZES
Earthquakes displayed on the maps are seen in various sizes and colors. The size of the quake icon refers to the magnitude of the earthquake. The color of the icon refers to the relative age of the earthquake.

The colors of the quakes is a question I am often asked. What do they mean? The colors of a quake represent the relative age of the quake. I know what you are thinking now, "so, what does THAT mean"? It's not a simple question to answer but I will try.

The color scheme always follows a yellow to red gradient. The very first earthquake to occur (within that dataset) will ALWAYS be yellow and the last quake to occur will ALWAYS be red. All other quakes will be colored based on where it falls on the timeline between the first and last quakes of the dataset.

The easiest way to explain this is to demonstrate a very small dataset. Lets say we are listing three quakes. The first quake occurred on Monday and is colored yellow. The last quake occurred on Wednesday and is colored red. The second quake occurred on Tuesday. This quake would be colored orange because orange is half red and half yellow. Now if the last quake occurred on Friday instead of Wednesday. The Tuesday quake would be more yellow than red because it is relatively older based on the data set.

A map that feauteres data for a full year (Jan thru Dec) will show quakes occuring early in the year as yellow, and red for quakes occuring later in the year.

Another way to look at the colors is to always remember that quakes that are of similar colors occurred around the same time. All quakes that occur on the same day will always be the same color (regardless of the dataset).

Creating a dynamic color scheme like this allows us to create some very unique and informative maps. Look at this example for instance. This map used a dataset that included only the 1971 San Fernando quake and aftershocks, and the 1994 Northridge quake and its aftershocks. It's now easy to distinguish which quake belongs to which event. This would be impossible if they were all the same color.

LISTS
Our maps will have an accompanying quake list which shows the Magnitude, Date, Time, location, and Depth of the quake.

All times are listed as UTC time.

The locations are determined using our own special software.

ARCHIVES
We are slowly working our way back in time to create maps and lists for previous years. We will go back as far as accurate records will allow.

SPECIAL REPORT: Hot Springs, North Carolina

2005-08-24T22:34:00.000-07:00

At 11:09 PM local time on August 24, 2005 a minor earthquake struck near the North Carolina and Tennessee border. The quake measured 3.8 on the richter scale. No injuries have been reported, but minor damage has been reported in surrounding counties.

The quake was felt as far away as Atlanta, Georgia, about 170 miles away.

Although this may seem like an unusual location for earthquakes, minor quakes in this area are not uncommon. The U.S. Geological Survey reports that since at least 1776, people living inland in North and South Carolina, and in adjacent parts of Georgia and Tennessee, have felt small earthquakes and suffered damage from infrequent larger ones. The largest earthquake in the area (magnitude 5.1) occurred in 1916 . Moderately damaging earthquakes strike the inland Carolinas every few decades, and smaller earthquakes are felt about once each year or two.

To be more specific I have looked at an area within a 50 mile radius of this current quake. By looking at the map (1971 - 2005) to the right (click for larger view), you will see that this specific area has had it's share of small quakes.

Since 1971 This 100 mile area has seen 77 earthquakes at or above 2.0. A dozen of these quakes were 3.0 or larger. This most recent quake has been the largest.

CLICK HERE to see the complete list of all quakes shown on our map.

IS BAJA READY?

2005-08-18T05:00:00.000-07:00

Those that study patterns of small earthquakes to help predict the next significant earthquake may want to take a look at Northern Baja California. The area in question is located about 45-50 south of the California border in central Baja California.

I have noted an area where five quakes have occurred over the last few weeks. I have compiled a 25-year list of earthquakes that have occurred within a 15 mile (26.5 km) radius of where these quakes have occurred. (NOTE: All quakes referenced in this report are of 3.0 or greater)

This area has a rich seismic history, but has been very quiet in recent years. Prior to these recent quakes, a 3.0 was recorded on December 13th of 2004.

This area has seen four earthquakes of 5.0 or higher in the last 25 years. The most recent was a 5.0 on 12/3/91. The other three were all 5.1 and they occurred on 8/31/88, 1/25/88 and 5/8/85. Three of the four had at least one notable foreshock.

The 5.0 of 12/3/91 had two quakes within about six weeks of the mainshock, but calling these foreshocks might be a stretch based on this data.

The 5.1 of 8/31/88 had a 3.3 foreshock four days prior and a two other small 3's within a few weeks.

The 5.1 of 1/25/88 saw seventeen foreshocks. Activity increased in August of 1987 and four significant foreshocks occurred within the month prior to the mainshock. Before August, the last quake was back at the end of January.

On May 8, 1985 there was a 3.3 foreshock followed by a 5.1 mainshock about two hours later.

Although having 4 quakes in this area in a short period of time is not unprecedented, it is something to keep an eye on. Larger quakes here tend to have foreshocks.

HERE is the complete list of quakes that was used for this report.

SPECIAL REPORT: Japan 7.2

2005-08-16T00:53:00.000-07:00

On August 16, 2005 at 11:46 AM (local time) a powerful 7.2 earthquake struck off the coast of Japan causing injury and damage in many areas.

As you can tell by the attached graphics, Japan is a very seismically active location.

The graphic above shows that the quake was centered offshore about 60 miles east of Sendai.

The graphic on the left shows all quakes above 5.0 that have occurred within 200 miles of this quake over the last year. CLICK HERE to see a list of all quakes shown on the map.

click on graphics for a larger view

Are Your Pets Ready for the Next Quake?

2005-08-13T11:23:00.000-07:00

Everyone living in earthquake country is probably tired of hearing the phrase "Earthquake Preparedness". Hopefully we have not tuned out these words and have actually taken steps to protect ourselves and our property.

But what about our pets?

The good people over at The Pet Place have posted some great tips to help us prepare our pets for the next big earthquake.

It is vital that your pet be properly identified
This is especially important in time of an earthquake or other natural disaster when pets become frightened and run away. Be sure your pet has a collar and tag. In addition other methods of identification are available such as tattoos, or micro ID implants through such companies as AVID (714) 371-7505 for info. Remember, even inside pets need IDs in time of emergencies.

Keep pets in control so they won't bolt and run away
Keep leashes or harnesses handy. Cat owners should also have carrier ready. One note about pet carriers - the large, hard plastic types are much more durable, especially in protecting pets from falling debris from damaged structures, etc.

Have bottled water, dry food and/or canned food ready
These should be easily portable. Don't forget a can opener if you have canned food that doesn't pop open, it is a good idea to have a week's supply in both your house and car.

If your pet needs medication, be sure you have an extra supply on hand
and ready to take with you as needed. A blanket might also be useful as bedding for you pet if you are forced from your home.

Some pets will immediately hide when they are frightened
Be familiar with their special hiding places. It might be a good idea to have their favorite treat or food ready to coax them out. In case of dogs, having them trained will make it easier for them to respond to your commands.

If you have a first aid kit, look to see what also might be handy to treat your pet in case of injury
And you might also want to purchase a pet first aid book as a reference guide in case of earthquake or other emergency. Remember vets and emergency animal facilities probably won't be able to help you initially.

After-shocks are almost inevitable in case of an earthquake
So be prepared to help your pet through these.

Both you and your pet are going to be frightened
But try and do your best to remain as calm as possible so you can take care of the situation, and your pet. Keep your voice at a normal pitch and talk in comforting tones. Hold and caress your pet as a way of reassurance. You'll find that your pet will also help calm you.

Watch to see that your pet avoids contaminated water or items such as spilled anti-freeze
And watch out for frayed or downed electrical lines.

If your pet becomes lost
check with your local animal shelter as soon as the emergency allows this. In past emergencies in different part of the country it is surprising how many people forgot this first step in getting their pets back.

courtesy of www.thepetplace.org