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New Zealand shows even strong building codes are no match for monster earthquake, experts say [Update]

New Zealand earthquake: Christchurch airport plans to reopen Wednesday; extra flights added

The devastation and loss of life in the Christchurch, New Zealand, quakes offer some sober lessons for California, earthquake experts said.

Click here to view an interactive on the New Zealand quake The damage shows that a sharp earthquake in a highly vulnerable area can get the better of strong seismic safety codes.

“If the dart lands right on you, it generates intense shaking and a lot of buildings that we think are safe turn out to not be safe,” said Susan Hough, seismologist with the U.S. Geological Survey.

The quake’s epicenter occurred less than six miles from the center of Christchurch, New Zealand’s second-largest city, far closer than a 7.0 quake in September, which had an epicenter about 30 miles away and resulted in no deaths.

 Also, the highest ground acceleration recorded was greater than 2G, or twice the acceleration of gravity –- which would make Tuesday’s quake among the most powerful in terms of ground-shaking acceleration on record, said Hough. It was strong enough to throw objects in the air.

“There’s only a handful of records of shaking” as strong as 2G, Hough said. “That’s quite extreme shaking.… Some earthquakes just have stronger shaking that affects buildings.”
 
By contrast, the ground shaking in the 6.7 Northridge quake in 1994 was less, recorded at 1.7G, Hough said. Hough has estimated that the strongest ground shaking in Port-au-Prince in the Haiti earthquake in 2010 was only about 0.5G.
 
Among the buildings destroyed in the quake were the Pyne Gould Guinness Building, which is described by local media as one of Christchurch’s best-known office towers, the Canterbury Television building, and the spire of the century-old Christ Church Cathedral. Staffers at The Press newspaper in Christchurch were trapped as part of the 102-year-old building collapsed, the newspaper reported.
 
Hough said it appears that some of the buildings that collapsed are fairly modern, which, “to me, says that we still have some things to learn.” She noted that during the 1971 earthquake in Sylmar, Olive View Hospital collapsed, even though it had just been built; earthquake scientists also discovered after the 1994 earthquake in Northridge that some of the welds in steel frame buildings weren’t as strong as previously thought.
 
“In this case, I strongly suspect the accelerations just exceeded the design values,” Hough said. As recently as the 1980s, seismologists had believed that earthquakes couldn’t generally produce ground accelerations greater than about 0.5G. But scientists began understanding that ground accelerations could be much stronger after reviewing new data from newly constructed earthquake monitoring stations.


Hough said Tuesday’s quake offers a lesson in humility to California, showing what can happen when a quake is centered so close to the city center and populated by dense structures, some relatively new, and some historic.
 
Thomas Jordan, director of the Southern California Earthquake Center at USC, said Christchurch was devastated in large part because of the shallowness of the quake, and the fact that the strongest shaking occurred precisely in the location of the city’s downtown area.

“It’s really the fact that you had a lot of buildings very close to the very strongest hypocenter, which means the strongest shaking was right there in town,” Jordan said.
 
Another question is how very tall buildings in California would fare in a big earthquake, particularly the long period of booming and shaking, roughly similar to the low tones in music. “We don’t have a lot of observations of how modern tall buildings will perform in really big earthquakes,” Hough said.
 
There are other buildings in California whose vulnerabilities in quakes are well-known, such as multi-unit condos and apartment buildings with tuck-under parking. They are vulnerable because their first floor lacks a wall that would help keep the building from toppling in a quake, Hough said.
 
Los Angeles has enacted an ordinance that has required bracing of unreinforced masonry buildings, Hough said. But other municipalities haven’t enacted such requirements, although state law does require unreinforced masonry buildings in California to have signs posted warning about their condition.
 
In 2003, a quake that rocked California’s Central Coast killed two men in Paso Robles, when the roof of a 19th-century building collapsed on them. Farther north, parts of the 19th-century Mission San Miguel collapsed.

[Updated at 8:55 a.m.: In Christchurch, Jason Ingham was preparing for a seminar on earthquake building standards Tuesday afternoon New Zealand time when the hotel where he was staying began to shake. He and his colleagues from the University of Auckland had studied damaged structures after the last Christchurch quake, which struck in September of last year. But he said they could feel immediately that Tuesday’s quake was more intense.

And while most of the damage last time occurred to unreinforced masonry buildings, many modern buildings were damaged Tuesday, said Ingham, who is an associate professor of civil engineering.

“Our instinct is that this exceeded the loads that even the modern buildings were designed for. We are almost certain,” said Ingham. “The assumption is that an earthquake of this size would have caused damage in any modern city anywhere.” ]

[Updated, 9:08 p.m.: New Zealand quake raises questions about L.A. ]

RELATED:

Small earthquake hits Huntington Beach

New Zealand quake victims, Wisconsin unions get aid from Los Angeles


New Zealand earthquake surprises experts with its level of destruction; California parallels seen

-- Rong-Gong Lin II and Sam Allen

Photo: A hostel for backpackers in Christchurch was damaged by the quake Tuesday. Credit: Simon Baker / Reuters

 
Comments () | Archives (32)

BUILDING codes do not apply to old buildings of past laws of different times because they are not being BUILT now.

"Hough said it appears that some of the buildings that collapsed are fairly modern, which, 'to me, says that we still have some things to learn.'”

That, according to a seismologist from the USGS.

First, she's apparently an American, not a New Zealander. She's knowledgeable about earthquakes, but what does she know specifically about NZ building codes? And this lack of knowledge shows in the "fudge words" she used: "appears", "some" and "fairly".

Your update, thankfully, contains the views of a building engineer and expert on earthquake building standards who was in Christchurch when the quake struck. His quotes, in contrast to those from the USGS seismologist, are useful. There was no reason to post pointless speculation when actual knowledge was out there to be had.

This article is in dire need of a review of its accuracy.

In 1972 after the LA earthquake it was shown the accelerations experienced where 1.0 Gs or more as the 1G accelerometers were pegged, vertically and horizontally. It was two (2) women killed in the Paso Robles quake not two (2) men, and the San Miquel Mission was very badly damaged but did not collapse. Given that these three items are relatively easy to check what is there about the rest of this article that I should believe? Not much.

Anyone in California (or other earthquake-prone area) who doesn't think that they need emergency water, food, clothing and meds stored outside their home is just playing russian roulette. Look at all the devastation to that city--and it's not as densely packed as LA or OC, so imagine what kind of problems there would be in the Southland with a similar quake.

If you check them out on Google-Earth you see that it's a city surrounded by fields...so even though the city is large it STOPS at some point. In Southern California the city just continues...so it would just be mile after mile of broken roads and devastation. Compounding the evacuation efforts and simple mobility within the affected area. In Northern California (SF, etc) it would be worse with the hills and high-rise area downtown. It was bad enough in the 80's!
Prepare-Prepare-Prepare!

Get those jugs of water, cans of food and "camping gear" set up outside your house or in your car. I think we'll all be playing "boy-scout" campout for a long time when it's California's turn.

The only protection from earthquake destruction is to switch to dome homes. Architecture as we're known it must adapt to reality.


Shakespeare says it best:

“If it be now, ‘tis not to come; if it be not to come, it will be now; if it be not now, yet it will come.

The readiness is all.”

(Hamlet)

***

Get ready to rumble!


Carl W. Goss

Los Angeles

What really scares me is that Orange County is largely built on the same type of silt and alluvial fill as Christchurch was, and just like them, we've got mountains and outcrops that could reflect and magnify the effects in some very unpredictable ways.

New Zealand Herald reported today that the rocky hills of the Lyttleton suburb may actually have reflected and concentrated some of the seismic waves, causing some of the patchy and inexplicably bad shaking in some parts of the city.

Coming to a location near you, in SoCal. Guaranteed.

These houses look as though they were designed by Frank Gehry.

I would imagine the fact that a 7.0 + quake had struck there months before didn't help matters. No one was killed, but there was considerable damage to many buildings, and it's hard to imagine that many more were not weakened and were therefore more likely to fail when the most recent quake hit.

Sort misleading, most people killed in Christchurch were in unreinforced masonry structures, you can't sell an unreinforced masonry structure in California. Most structural engineers will tell you that design limits on buildings only mean that the building won't collapse in a strong earthquake and the newer buildings did this. Thirdly, this is likely not a problem with the structures, but with the foundation. The Kiwi's have been slow to pick up on liquefaction issues and in general, the field of soil-structure interactions is very new.

Please pass this article on the the Board. I hope they will encourage the Bay Club members to reconsider their stance on earthquake insurance and bring ithe issue to another vote. Having suffered the loss of a building at my work during the 1994 LA quake, I know the nightmare that ensues when insurance is not available.

Cheryl Jordan Building 10

this was hardly a MONSTER Quake ... ... ...
it was shallow and of relatively long duration,
but NOT a Monster.

So we better spend billions of money we don't have to make even our strongest buildings better!

Let's face it folks, when Mother Nature says fall down, buildings must obey!

Please remember that, while large, this quake was by no means a "Monster Quake." The only reason it hit so hard is because it was shallow. And, while, I'm no expert, I'm guessing that a lot of the buildings that came down this time were weakened in the prior shake.

While it's true that if the dart lands on you, watch out, the dart landed on Northridge (the epicenter) in 1994. We did not see this kind of damage and death. To my knowledge California has the strongest building codes around. Everything is ridiculously engineered. And each time we have a major earthquake, the codes get stronger.

The house in the picture would not conform to any California sesmic building standard.

What an excellent report, so nice to hear it from another perspective other than the ricterscale (sp). It makes me fell a little more at rest here in Canterbury that it was a pretty unique event, as we are all still so worried that this will have triggered another quake. Thank you, for this and for all of your help that your country and others have offered. We are truely blessed to have this support.

What's worse is the lying by the USGS for the past 6 decades and pooh poohing the risk in the LA area of a super quake. Recent research at several California universities have proven that quakes similar to the Fort Tejon and Wrightwood and San Fran quakes occur every 88 years. And super quakes, with hundreds of miles of the San Andreas slipping at once, occur on average every 180 years.

The last super quake was 1690 and is 140 years over due!!

They are also lying about the San Andreas being a strictly strike slip fault system. Recent research also proves that every 500 to 1000 years the San Andreas does a subduction similar to the Cascadia, Indonesian, and Chili faults which produce massive 9+ quakes.

Beware Californians! Beware! It's coming soon and NOT to a theater near you but in real live action!

Mother Nature says, "Take all your seismic ratings, safety codes and other trivial, human minutiae and SHOVE 'EM!"

"When mama wants you, she will come and get you...and ain't a thing you can do about it."

The peak ground acceleration was more than 2G (that's twice the acceleration of gravity). I'm not sure how much higher it needed to be before some of the "experts" here consider it to be a monster. The Richter scale shouldn't be seen as the sole measure of how dangerous an earthquake is - there is much more to it than that.

WHAT DO PEOPLE EXPECT WHEN THEY LIVE ALONG THE RING OF FIRE, FOR GOD'S SAKE; OR, ALONG THE SAN ANDREAS FAULT. HUMAN HUBRIS AT WORK. THE ANSWER IS, MOVE TO A SAFE PLACE! DUH...

WHICH, is worse: the arrogance of the EXPERTS, or the stinginess of the bean counters? Neither! It's the politicians, taking payola!

I was shocked to find that the LA and Orange County areas of California are actually the "Broken Cookie" part of the Andreas Fault.
If you google past earthquakes you'll see that the fault is pretty much a crooked line from north to south until you reach the LA area. The fault line then "crumbles" into many small fault lines.
People living in LA and surrounding areas need to know that they are living on the worst possible "broken cookie" section.
Cavaet: You cannot put a broken cookie back together again.
LeeB.

Several years before the 1992 Cape Mendocino earthquake: two engineers who lived next door to each other got into a big argument about how to retrofit/earthquake proof a home. One rebuilt his house and doubled all the building requirements, if it called for a 2x4 he put in a 4x4 and so forth and the other had the house moved, drove pillars into the ground and then put the house back, tying the house to the pillars. The house that was double code fell to the ground and the house that was tied to foundation pillars had minimal damage. Food for thought.

 
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