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Sat 23 Dec, 2006 02:47 pm
Posted on Sat, Dec. 23, 2006
Third earthquake in four days shakes San Francisco Bay Area
Associated Press
BERKELEY, Calif. - The third small earthquake in four days rattled the San Francisco Bay Area Saturday, but there were no immediate reports of injury or damage.
The temblor that struck Alameda County at 9:21 a.m. had a preliminary magnitude of 3.5 and a depth of about 6.1 miles, according to the U.S. Geological Survey.
The epicenter was about 2 miles from Berkeley, 3 miles from Piedmont and 3 miles from Emeryville, across the bay from San Francisco.
Residents throughout the Bay Area reported feeling the jolt, but Berkeley police said there were no reports of anyone being hurt by the quake.
Saturday morning's earthquake was similar in magnitude and location to temblors that struck Wednesday and Friday.
The three quakes erupted along the Hayward Fault, which geologists believe is due for a large quake in the potentially lethal 6.7 to 7.0 range.
http://en.wikipedia.org/wiki/Hayward_Fault
Lots of info on the area around the Hayward fault zone. It includes oil refineries, rapid transit, underground tunnels, underwater transportation tubes, many hospitals, universities, major highway arteries, ports, railroads, sports stadiums, several major bridges, and lots of people all residing on top of or near the fault.
Yikes! Please tell me there's a comprehensive emergency plan in place (and they're not relying on FEMA).
Some planning has been done, but not nearly enough actually put into action.
Most people are told to plan to take care of themselves. Some have emergency kits and family plans. Some companies have safety committees that have written plans. The Loma Prieta quake in '89 did a lot of good in that respect.
I spent most of my life in that area and it is not nearly as prepared as it should be, especially after seeing how well the "disaster planning" helped in New Orleans. I hope I am far enough away from it now. Experiencing another '89 type quake is not on my list of things I want to do again. I have my emergency kit in my closet, just in case.
Dec 24, 2006 12:36 pm US/Pacific
Scientists: Recent Quakes Not Sign Of The Big One
Seismologists from the US Geological Survey say the three small earthquakes that erupted along the Hayward Fault this week do not necessarily mean the big one will strike soon.
Geologist David Schwartz calls the timing of the quakes, which were all in the 3.5 magnitude "random and coincidental."
They occurred over four days in a part of the fault that's prone to quakes. There have been 39 recorded earthquakes measuring between 3.0 and 4.0 along the Hayward Fault since 1970.
However, none was followed by a larger quake.
An earthquake measuring 5.0 or higher in magnitude or greater might indicate that a bigger temblor was coming, according to Schwartz.
But seismologists say there is a 27 percent probability of an earthquake measuring six-point-seven or greater along the Hayward Fault by 2031.
Two more quakes on Hayward fault yesterday and today.
Minor quake reported near Union City
Bay City News
Sunday, December 25, 2006
(12-25) 11:01 PST -- A minor earthquake was felt in the East Bay this morning, capping a series of temblors that rattled Bay Area residents last week.
The U.S. Geological Survey Web site posted preliminary reports of a magnitude 2.6 earthquake that struck at 10:07 a.m. and was centered two miles northeast of Union City.
Union City resident Susie Callahan reported the quake felt "like two sharp jolts, like someone was closing the garage door twice."
The earthquake does not appear to have caused any damage, the Union City police have not received requests for help.
Saturday morning's 3.5-magnitude earthquake, and the temblors that preceded it, are not necessarily a precursor to a larger quake in the area, a U.S. Geological Survey seismologist reported.
Saturday's quake at 9:21 a.m., centered two miles east-southeast of Berkeley, was the third in four days in roughly the same location, according to the USGS.
A 3.7-magnitude quake struck Friday at 10:49 p.m. and another quake of the same magnitude hit Wednesday at 7:12 p.m., according to the
USGS.
Earthquake records going back to the 1970s show that there is usually about one magnitude 3 or 4 quake every year in this vicinity, USGS seismologist David Oppenheimer said.
An earthquake is created when stress builds up and there is a slippage on parts of the fault that are not creeping, Oppenheimer said.
In this area of the Hayward fault, "we think there is a creep event going on deep within the fault,'' Oppenheimer said.
But, according to Oppenheimer, it is more difficult to speculate if there may be more earthquakes in the area in the near future.
According to Oppenheimer, since 1970, within a 6-mile radius of these earthquakes, there have been 37 magnitude-3 seismic events, "none of which have been foreshocks to the magnitude 7 we've been worried about,'' he said.
"That doesn't mean we should all relax,'' Oppenheimer said, adding that after all the earthquakes, there is a slight increase in the probability of a larger quake on the way.
Copyright 2006 by Bay City News, Inc. Replication,
These are like getting long-term hurricane or tornado warnings that take many decades to arrive. In the case of the Hayward fault, it is more like waiting to see if the wind currents will bring an offshore hurricane in your direction. It might not be this hurricane, but you know it is just a matter of time and all you can do is prepare or get the hell outta dodge.
I'm 350 miles south. Perhaps it will strike me next!
Were you there for the Northridge quake, Nick?
Not good news for those living along the Pacific Ring of Fire, which includes the Hayward Fault.---BBB
Powerful earthquake reported off Taiwan coast
Tsunami fear 'over,' official says
By Annie Huang
The Associated Press
December 26, 2006
TAIPEI, TAIWAN A powerful earthquake struck off southwestern Taiwan today, briefly prompting fears of a tsunami on the second anniversary of the quake and deadly waves that killed thousands in south Asia.
Taiwanese media reported one person died and three were injured when their home collapsed in the southern city of Pintung. Other reports said city streets had cracked and a major bridge was damaged. They said fires were burning out in the area, apparently caused by downed power cables.
The quake was felt throughout Taiwan. The U.S. Geological Survey estimated its magnitude at 7.1, while Taiwan's Central Weather Bureau measured it at 6.7. It was followed eight minutes later by 7.0 magnitude aftershock, the USGS said.
Two hours later, an official at Japan's Meteorological Agency said there was no longer any danger of a destructive tsunami headed for the Philippines, as had been predicted.
"The danger has passed," said Hiroshi Koide of the agency's earthquake section. "We predicted tsunami based on the depth and magnitude of the earthquake. But ultimately, it appears no large tsunami were triggered."
Phone lines were cut in the southern cities of Kaohsiung and Pingtung, possibly hindering reports of damage by residents, the CTI Cable News reported. Several high-rise hotels swayed violently in Kaohsiung, it said.
Liao Ching-ling, a 30-year-old manager at Kaohsiung's Ambassador Hotel, said she had never before felt such a strong quake: "The building swayed so badly that many panicky guests ran out of their rooms and into the streets."
The initial tremor was centered at sea about 13 miles southwest of Hengchun on the southern tip of Taiwan, the bureau said. Hengchun is about 260 miles south of Taipei.
Quakes frequently shake Taiwan, which is part of the Pacific's "Ring of Fire," an arc of volcanos and fault lines encircling the Pacific Basin. Most are minor and cause little or no damage, but a 7.6-magnitude earthquake in central Taiwan in September 1999 killed more than 2,300 people.
A 9.1-magnitude earthquake off the coast of Indonesia on Dec. 26, 2004 caused a tsunami that killed at least 230,000 people in 11 countries. Those waves reached as high as 33 feet.
back i the days in grad school when I used to monitor the seismic equipment and do the Mag and epi/hypocenter calcs for the big guys to announce to the press, we always had bets made at how the pattern of circular temblors would occur throughout the edges of a series of plates. Watch this one along the Clipperton and Clarion next.
Butrflynet wrote:Were you there for the Northridge quake, Nick?
I've only been here a few months butterfly. But I have heard the stories that it was pretty nasty even here.
Farmerman, I've been watching ever since the '89 quake. I've been able to see distinct patterns while watching the animated maps of a weeks' worth of quakes around the world. It is interesting to see how a quake on one side of the pacific seems to trigger quakes on the other side.
The last year I've been watching a gradual northward movement of quake locations. There has been a huge increase in activity of smaller quakes in the last month on the US side, then it quieted down for a week and then several large quakes occurred on the Asian side again, and now the US side is moving again. It's been traveling upward from South American along the coast. Alaska and Central America have been moving quite a bit. California is starting to creep northward a bit too. The quiet spot is the Northwest and Canada. There hasn't been much other than the occaional quake out in the ocean up near Eureka.
Watching the animated quake occurences reminds me of watching the light show in Close Encounters of the Third Kind scene when the alien ships and the US military are doing their musical communicating back and forth. Both sides of the Pacific Rim are communicating back and forth with each other as they creep northward.
Nick, be glad you didn't experience the Northridge quake. I was smack in the middle of the Loma Prieta one, in Oakland within a few blocks of the freeway that collapsed. That is something I never ever want to experience again.
I was on a conference call with people in our San Jose and Concord offices and it was very odd and then very scary. San Jose felt it first, then Oakland and then Concord. As the file cabinets in my office started flipping over onto the floor, I yelled into the phone for everyone to hit the deck and get under their desks. We had ceiling tiles falling on top of people in office cubicles, paintings falling off the walls and sheetrock in some offices separated at the corners.
We were at the Oakland City Center in a building that floats over the underground parking garage. I felt like I was going to get seasick from all the rocking back and forth. Then there were the awful smells days later from the collapsed freeway. I still shudder thinking how close I came to being on that freeway at the time. If we hadn't been on that conference call, I would have been heading out the door driving home on it.
I know that because of that experience I am now overly sensitive to earthquakes. Everytime a heavy truck or bus goes by on the roads out here, it shakes the apartment building. Drives me nuts and I always have to check the USGS site to see if we had any local quakes that I excused as more truck rumblings.
Anyway, watching the earth's ballet movement via the animated maps at USGS has been an interesting study through the years.
Our offices in the Northridge area had the same sort of damage and experience during that earthquake.
Sitting at work for hours, listening to radios and watching TV for news until it was deemed safe enough to leave, and then driving home after dark in streets without lights or traffic signals through groups of people roaming the streets gave me a pretty good lesson in the need for individual emergency planning and preparation. We can't rely on the companies or local governments to be able to help.
That all sounds really cool! I can hardly wait for my forst earthquake! On second though -- maybe I can wait a LITTLE while.
USGS
U.S. Geological Survey site:
http://www.usgs.gov/
thats nothing, we get hundred of earthquakes every year in the UK
three in one day in scotland recently
http://news.scotsman.com/topics.cfm?tid=907&id=680632003
So do we, Steve. The media only reports the ones greater than 3.0.
The USGS has maps showing the ones less than 3.0 if you're interested in seeing the total number and not the recent largest ones.
Tonight's quake was widely felt all the way into the Sierra Foothills. Very little damage, mostly pictures, books and supermarket stock falling off shelves. I feel stronger jolts from trucks going by my apartment here in the eastern portion of Sacramento Valley. Really glad I wasn't closer to relive the memories of the Loma Prieta quake. -- Lynn
Quote:
By Leslie Griffy and Sandra Gonzales
5.6 quake hits near Alum Rock, strongest since Loma Prieta
Mercury News
Article Launched: 10/30/2007 08:19:16 PM PDT
A moderate, but powerful earthquake struck San Jose just after 8 p.m. tonight, shaking buildings and prompting rattled residents to pour out of their homes.
The temblor on the Calaveras Fault lasted about 30 seconds. The U.S. Geological Survey preliminary magnitude estimate was 5.6, making it the most powerful quake to hit the Bay Area since Loma Prieta, Oct. 17, 1989. That was a magnitude 6.9.
The epicenter was five miles miles from Alum Rock, seven miles from Milpitas and nine miles from San Jose City Hall with the earthquake originating 5.7 miles below ground.
Shaking was felt throughout the Bay Area. Eleven aftershocks with magnitudes of 1.3 to 2.1 were reported by 8:45 p.m.
There were no immediate reports of major damage, though cellular and landline telephone service failed for a time in some areas.
The latest updates:
10:01 p.m.: Quake brings back bad memories in Santa Cruz
In Santa Cruz, where one in three buildings was destroyed along Pacific Avenue downtown in the 1989 quake, tonight's shaking brought back bad memories.
"It gave me a sick feeling in the pit of my stomach. It's more like physical memory than anything else," said Mardi Wormhoudt, who was Santa Cruz mayor in 1989, and was eating dinner on the Santa Cruz Wharf. "It's amazing how it comes back. Unfortunately, it brings back so much of what was so horrible."
Neal Coonerty, owner of Bookshop Santa Cruz, which was destroyed in the 1989 quake and became a symbol of rebirth later, was upstairs in his home when Tuesday's quake hit. There was no damage, but the shaking was something he hadn't felt in 18 years and he rushed to call his daughter to find out if she and his new granddaughter were OK.
"It was forceful. It is nerve-wracking. It takes your breath away," Coonerty said. "You are always hoping the 1989 equarthquake was once in a lifetime. But this is California and we all know it probably won't be. It is unnerving."
9:41 p.m.: Scientists not surprised by quake's magnitude
Earthquake scientists said they were not surprised that a 5.6 quake originated on the Calaveras Fault.
"We think the Calaveras is capable of a quake of maybe even a magnitude 6.4," said Tom Brocher, coordinator of Northern California earthquake hazards investigations for the U.S. Geological Survey in Menlo Park.
Brocher said that a quake with a magnitude 5.6 typically wouldn't be associated with a lot of damage: "Maybe things tipping over in grocery stores. Maybe here or there a pane of glass broken," he said.
Although there have already been aftershocks recorded, they have been minor. Seismologists don't anticipate another large quake on the fault soon.
"Probably this is the largest we're going to have," Brocher said. But there is, he conceded, a 5 to 10 percent chance of an earthquake this size or larger occurring on the Calaveras Fault within the next seven days.
It took some time for seismologists to pinpoint on which fault the earthquake originated. Both the Hayward Fault - which is considered due for the 'Big One' - and the Calaveras Fault slice through that area east of downtown San Jose.
When asked if an earthquake so close to the Hayward Fault could ultimately end up setting off a quake on that fault as well, Brocher said he didn't want to speculate.
"But," he said, "we'll be looking at that."
9:33 p.m.: VTA workers inspecting for damage
Valley Transportation Authority workers are checking the light rail lines for damage and trains have been slowed.
Power went out in sections of San Jose's Japantown one man said, but at Teske's German restaurant, not a glass was out place.
Owner Hans Baumann said the place swayed one way and then the other, the chandelier in the main dinning room went up and down and side to side. A diner yelped. And single display bottle of German liquor fell to the floor but didn't break.
"I knew it was a big one when it started to move in different directions," he said.
He had been standing near the kitchen watching the basketball game on the TV when the quake struck. "But nothing here broke. It was like that during the last big one too. This is an old building."
9:16 p.m.: South Bay hospitals report phone trouble, but no major damage
At local hospitals, the lights stayed on, no major damage was reported and patients appeared to be unharmed during preliminary checks - although everyone felt the rolling tremors.
At Regional Medical Center of San Jose, the closest hospital to the quake's epicenter, spokeswoman Victoria Emmons said the hospital could not make phone calls but could still receive them.
The earthquake was not severe enough to trigger an internal disaster alert at Good Samaritan Hospital, and it appeared only to disrupt some Nextel cellular phones, said Good Samaritan spokeswoman Leslie Kelsay.
At county-run Valley Medical Center, however, five elevators shut down in a building that once housed the main hospital but is now used for outpatient procedures and offices. No patients were in the building at the time of the quake, said spokeswoman Joy Alexiou.
The building was converted into offices because it was deemed seismically unsafe according to a state law that requires hospitals to retrofit buildings to meet higher earthquake safety standards.
"It really does prove the point (about hospital safety)," Alexiou said. "'We're feeling very fortunate nothing else happened to us."
8:31 p.m. Residents in downtown San Jose pour into the streets to check damage
On the north end of San Jose's downtown, shaken residents left apartments, condos and homes to survey the damage. Luckily it was minor.
The quake shook a metal garbage can into a car parked on the street and at 350 North 2nd a water pipe broke, streaming water into the parking garage of a condo building.
"At first I thought it was a train," said David Eaton, who lives in the building. "But it went on way too long. And then I heard things starting to fall and I knew it wasn't the train."
Although it was Eaton's first big earthquake, he was prepared. He stood outside of his building with his two dogs, carrying a flashlight and other emergency equipment.
"This building is only two years old but it really shook," he said.
Down the street near a VTA bus stop driver Christopher Archuleta stood outside of his line 23 bus with a big smile.
"That was fun," he said shaking his head.
He had been driving when the wheel started to shake and then bus started to sway.
Two of his passengers told him it was their first earthquake. He said the girls seemed nervous and were unable to get their AT&T cellular phone to work, but were able to borrow another passenger's cell phone to let their friends know they were OK.
8:22 p.m.: Cupertino resident reports 'entire house shook'
Vishram Dalvi said that his "entire house shook, pictures swayed, a few things fell off. We ran downstairs with the children but everything stopped. I am worried with what they say about the big one being long overdue now- was it every 140 years?"
In Palo Alto, one resident described the earthquake as feeling as if a "big rolling freight train just went through my backyard."
Within minutes, fire stations in Palo Alto reported in to the dispatch center that there was no damage to their stations.
My boyfriend lives in San Jose, he is OK but his cats are upset.
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