Earthquake tonight

[Rob Beale]

We were hit by a large eathquake tonight in New Zealand, 8:55pm local time. It was centred 50 km southeast of Gisborne in the sea at a depth of 40km with a magnitude of 6.8

I was in town with my family when it hit and experienced the longest rolling shake I have ever felt! My daughter and I were on a seat on the footpath, and the cars were rocking rapidly back and forth on their suspension. We moved out onto the roadway clear of the verandah and waited for it to subside - it seemed way longer than a minute of shaking!

We heard a loud bang to the right of us up the road, and we now know that a verandah collapsed, and a couple of parapets have fallen: one through a verandah, one through the roof of the shop.

Power was restored after about 20 minutes, though phone lines were jammed for over an hour.

No doubt there will be more damage found in the morning!

I can report that my C8AX is safe and the gear in the shed is still in place, just the odd thing fell over or off a shelf!
I'll check the chimney tomorrow, and the brick veneer on the house. We like timber framed houses here so they can roll with the shake!

I think I've settled down enough to go to bed!
Rob

ps this is the local news paper report posted one hour after the shake:

http://www.gisborneherald.co.nz/Defa...e420b903008130

Ouch ... nasty ... sounds like its done a fair bit of damage and I sure hope aftershocks or another quake do NOT happen ...

I've experienced heavy duty rumbling shaking of a bigger earthquake, not damaging though, just aggressive shaking ... though a big semi trailor truck had run into our fourplex ... Vancouver probably about 1975/76 ... I packed up our whole two bedroom apartment, got rid of all my furniture and was moved to Winnipeg in TWO WEEKS!!!! Ran home to mommy with my baby girl schnell. Scared the crap out of me, obviously

My youngest kids dad lives San Fransisco, now Oakland, was still in San Fran when that bad one hit there, sometime around 1989 or close to that year? His house, baker St, near Haight Ashbury area was violently shaken up (a glorious old 4 story Victorian as are many houses there) ... insane scarey time ... our daughter saw the news, shew was 5, and came yelling and running to me "Mommy mommy, Daddy Daddy earthquake San Fransisco ,.... " we were both pretty sacred and worried about John, we couldn't get through down there by phone of course, until he was finally able to call us hours later and tell us he was okay and so were other family members and friends ... earthquakes, wow, THAT one was a very bad one Those bridges. Awful. My little rumbles nothing compared to that, but the violent shaking and weaving/waving apartment we were in was .... well ... furniture walked by themselves ... intense.

End of free associaltion flow here ...

I figure that when the furniture starts walking by itself then its time to run

[Rob Beale]

Earthquakes are just one of many natural phenomenon, but more common in our "Shaky Isles" and of course California and Japan.

Despite good engineering, damage is more widespread than was apparent last night. Many older Edwardian buildings are damaged which is a shame as they have a character all of their own. They had survived earthquakes in 1931 and 1966 that badly damaged other buildings of that era.

Most damage is to brick masonry: the steel and concrete of modern structures resists damage generally, but a brand new hotel has been badly damaged.

Damage to homes is varied, with many losing lots of possessions flung around the house and smashed while others are virtually unscathed. Christmas will be sombre for many families.

Best wishes to all for the festive season
Rob

[Ryan]

Best of luck Rob for you and your community over the Christmas/New Year period.

I second Ryan's responses ... and I hope the community can pick up whatever pieces they can and get moving as quickly as possible ... although I imagine some people's lives and finances are turned upside down and it will be hard for them. I especially feel for anyone who lost someone, I read mention of some deaath/s in the storiy yesterday.

All the best.

Karmen

[Tony Smith]

Hang in there, Rob. I hope this doesn't put the NZ Cricket team off their game!

Heard on the news that there was one death attributed to the quake, a heart attack victim, as well as the extensive damage mentioned.

Amazing only one death reported and to heart attack. Wow. Could have been more ... read the part about the rain saved some diners lives .........

This from one of our Canadian news site Canoe:

Quake rattles north New Zealand

By CAPTION 1Ray Lilley





Hole ripped in the roof of a book store, Friday, December 21, 2007, after a magnitude 6.8 earthquake struck Gisborne, New Zealand. (THE ASSOCIATED PRESS/NZPA, John Cowpland)

WELLINGTON, N.Z. - A strong earthquake struck New Zealand on Thursday night, collapsing at least three older buildings in one coastal city on North Island, sparking small fires and forcing authorities to declare a state of emergency.

Sixteen minor injuries were reported in the port city Gisborne, which was hit hardest by the quake and suffered the most property damage, although it was felt all over the country, officials said.

The magnitude-6.8 quake, which struck at 8:55 p.m. local time was centred in the Hikurangi undersea trench off North Island, 40 kilometres below the surface and about 50 kilometres southeast of Gisborne, the GNS Science geological agency reported.

The U.S. Geological Survey recorded the quake at magnitude 6.6.

The quake did not trigger a tsunami warning at the Pacific Tsunami Warning Center in Hawaii.

Police cordoned off a large part of Gisborne's central business district until engineers could inspect damaged buildings and ensure they were safe to enter, said senior police Sgt. Moira Brown on Friday.


"We have got a lot of damage and are still assessing the situation," police Insp. Waata Shepherd said.

"Some roofs have collapsed. We are still trying to ascertain the amount of damage."

The central city area had been "locked down" because of the damage, he said.

Power lines were down in some areas and the quake had left a huge hole in one of Gisborne's main roads, he added.

Mayor Meng Foon said the fire department put out 10 small blazes. Water and sewage systems were still working.

Gisborne District Council spokesman Vance Walker told TVOne News three historic buildings had collapsed in the centre of the city.

Structural engineers confirmed at least 12 buildings had been badly damaged, said Gisborne Civil Defence controller Jon Davies.

Earthquake Commission insurance manager Lance Dixon said early estimates indicated $23 million in damage was incurred.

Stephanie Butler said her two-storey Bernina sewing shop in Gisborne was destroyed when a next-door building toppled onto it.

"One side is completely missing...and part of our roof and even the light tubes have blown onto the building next door" by the force of the falling building, she told National Radio.

Gisborne restaurant owner Tony Taylor said rain that forced diners to eat inside probably saved their lives - after a chunk of brick and concrete crashed on to an outside table.

"It was a Godsend that it was raining," he said.

"Otherwise those guys would be dead."

The table and chairs were "absolute pancakes" he said. Large cracks running through outside walls threaten the future of the old brick abattoir building, he added.

Dennis Munro, a farmer near Wairoa, a town about 30 kilometres south of Gisborne, said he had extensive damage to his house, including a toppled chimney, cracks in the walls and a collapsed kitchen ceiling.

The house was a "real mess," with Christmas gifts destroyed, he said.

The National Crisis Centre was activated to assist local agencies dealing with the quake's aftermath.

Quake damage was reported from towns up to 200 kilometres north and south of Gisborne.

Vulcanologist Dr. Warwick Smith of GNS Science said the quake was not strong enough to spark a tsunami off the coast.

"My judgment call...was that 6.8 wasn't big enough for a tsunami," he told National Radio.

"The ocean floor has to either be uplifted or subside to move that water, and 6.8 isn't big enough."

One caller, who identified himself only as Brian, said his family sheltered in doorways as the quake rocked Gisborne.

"That was a ride and a half. It was freaky," he said.

Murray McPhail, who lives about 10 kilometres outside Gisborne, said the quake caused waves in his swimming pool.

"Stuff came out of cupboards, bottles fell off walls, ornaments fell," McPhail told NewstalkZB.

"It was pretty violent. It was certainly a decent shake."

New Zealand sits above an area of the Earth's crust where two tectonic plates are colliding. It records more than 14,000 earthquakes a year - but only about 150 of those are felt by residents and fewer than 10 do any damage

http://cnews.canoe.ca/CNEWS/World/20...734914-ap.html

[Rob Beale]

That "Canoe" report is very good.

Tsunamis have hit Gisborne's coastal area often in the past. One in the 1940's hit just to the north and washed a bridge away as well as flooding a pub and destroying at least one house.

Since the Boxing Day Tsunami, scientists re-evaluated the threat to NZ and found that good old Gisborne is at worst risk. A major earthquake of magnitude 8 or more hitting in the same area as Thursdays quake could cause an undersea landslip into the Hikurangi trench which lies offshore, parallel to the axis of the island. The warning period is about 20 minutes!


Well Tony I think its time the Black Caps changed from cricket to some other game: I don't see how the sponsors justify their costs.

I took a walk through town yesterday to have a look. There are still 3 blocks cordoned off. Workers were removing loose masonry on some buildings. Two of the worst hit shops were victims of insecure neighbours - in one case a complete first floor wall fell through the roof of a single storey neighbour.

On the night of the quake we found a lump of masonry lying on the pavement 10 metres away from our car - the lump was the size of a stove! and had crashed through the verandah.

Rob

[Rob Beale]

Christchurch was hit this morning at 04:35 local time by an Earthquake of magnitude 7.1 (Originally reported as 7.4) The epicentre was close, at 30 km away.

Damage is extensive, but no loss of life, just 2 serious injuries so far.

The damage is generally older brick buildings, where the front walls have fallen out into the street and crushed cars below.
Usually the floors are still in place, so no collapses as happens overseas.

Lots of houses have lost their chimneys, and brick veneer walls have fallen off some timber framed houses

Watermain and sewer pipe damage in some places, so that has public health implications.

Reports are still coming in as day breaks and authorities inspect and assess the extent of the damage.

Christchurch is about 1000km away from my home, but all kiwis are well aware of the effects of earthquakes, and most have family or friends nin the area.

Best wishes to all MLU members in Christchurch

Rob

[Ryan]

Best of luck to all over the pond. Have been watching this on the news this morning. Very fortunate that no one was killed.

[Ken Hughes]

Hi there Rob,Did the earth move for you?,It did here in Brighton Dunedin,everything was swaying back and forwards,My step son and his good lady and grandchild live in central Christchurch city,they are still without power and water at 330 pm today,they are with friends with power etc for now and are ok

[Ganmain Tony]

Hope everyone and their trucks are not bent.

Stay safe all you Kiwi boys and girls.....

[Lynn Eades]

My cousin just told me that his (its a dream home) is wrecked. Built on a concrete slab, It is near the Avon river, and is therefore built on river silt and rock The whole lot has become liquid, and slumped, no doors or windows can be opened or closed. We feel for them, but can't do a thing for them.

[Rob Beale]

In Christchurch and the surrounding area the damage is widespread, but fortunately no deaths reported as yet after 24 hours. The worry is that not all buildings have been checked yet. A lot of the damage will be shown on TV news worldwide now.

The size of the city and its proximity to the epicentre, have resulted in the large number of damaged buildings.

Thanks to our long history of earthquakes since European settlement began in the 1850s, NZ building practice has modified the old English style of brick buildings which were built to withstand gravity and a bit of wind only.
The 1931 earthquake that destroyed Napier and Hastings prompted a major change, and now all building elements are tied together: walls, floors and ceilings. A lot of old buildings have been retrofitted with ties and bracing, and all modern structures have extensive bracing in all directions.

Most of the damage you have seen on TV is where curtain walls have broken free and collapsed, but you will see that the floors are still in place. This is important as the occupants are not crushed by falling floors and are able to be exacuated after the shake stops.

Decorative features like parapets are also likely to break free, hence all Kiwi kids are taught to never run outside, but to get under strong furniture, or into doorways to shelter during the shake. We wait till its over before getting out!
The big death tolls in overseas Earthquakes are due to buildings collapsing and the floors pancaking down on each other. (There is little hope of rescue then).

On the domestic scene, it is chimneys that fall frequently, and crash through ceilings. This is despite advice to homeowners over many years to strengthen the ceiling around chimneys. Most brick chimneys in NZ homes have been replaced by concrete ones, at least at the top, as a succession of earthquakes over the last century have knocked them down!

There are many grand old homes in and around Christchurch that were built in the English pattern, and they are showing quite extensive damage, as their brick walls have collapsed, and in many places roof structures have collapsed, and floors are unsupported. The multiple chimneys have not helped either!

The biggest worry now is the hidden damage: to utilities under the ground like Water mains and Sewers, and to structural elements of buildings. This will be major cost, and will need extensive survey work.

The odd geological feature is the sand volcanos that have "erupted". This is where the ground water and the sand under the area has been liquified by the vibration and been forced up through cracks and fissures as fountains! It all stabilises once the shaking is over, but structures may tilt, and cracks in roads need filling to make them passable. All bridges are closed as a matter of course until they are checked to ensure they are safe and undamaged.

I know there is a lot of misinformation about earthquakes, particularly where they are not experienced. I am very proud of how NZ has become a world leader in earthquake design and construction, (with California and Japan) and is able to save lives in quakes of a size that cause massive loss of life overseas. NZ design innovations have been constructed around the Pacific Rim, and have been proven in earthquakes like Kobe in Japan, and in California.

One idea is Lead-cored rubber bearing pads, which absorb the energy from the ground and protect the building above. (They are replaced after the quake)

I am a local council Engineer, and have a long term interest in this!

Well take care
best wishes from the Shakey Isles!

Rob

[cliff]

Bob I was a building inspector for Franklin District Council just South of Auckland before shifting to Queensland in 1999 and we were updated on new Earthquake design features and changes on a regular basis. It was a bit of a culture shock at first as here they concentrate on the uplift from Cyclone winds rather then the bracing and design for earthquakes. I'd hate to see even a small one in this area as it would destroy about 90% of all the buildings.

I phoned my Brother who lives in Timaru and got news about a cousin who lives at Ashburton. No damage and no injuries there to either which relieved my worries about them when I heard about the quake. Our news here last night estimated damage at 1.5 Billion Dollars and rising and I know from experience just how long it will take to get things back to the way they were before this happened. Just glad it did not happen at peak shopping hours and only 2 were seriously hurt.

[Rob Beale]

Cheers Cliff,

Do you remember that earthquake in NSW (Wollongong I think), about 1985?
It caused widespread damage, yet was only low magnitude.

The "leaky building" problem in Auckland and elsewhere seem to have come about when they allowed new building practices at the same time as changing timber treatment standards to allow alternatives to boric treatment of radiata pine softwoods. Instead of a pesticide with fungicide properties they used pesticides only to combat "wood borer insects", and any minor leaks now resulted in rotting.

I was in Turkey last month visiting Gallipoli and was looking at some new buildings in Ecebat. What scared me was the skinny columns compared to the floor slabs. To me this is a recipe for disaster, as there is no bracing between floors to stop columns failing and the pancake effect of falling floors. Maybe their earthquakes occur in the eastern side of the country?

In Oz the wind will be a greater danger, and design standards will show this. We use "cyclone ties" to hold roof trusses down but they are pretty useless in a cyclone!

We have a NZMVCC meeting in Christchurch next month, so I hope to get a look at some of the city then.

all the best for all our friends and relatives in Christchurch and mid Canterbury

regards
Rob

ps. well done the Wallabies!

[cliff]

worse still was them allowing untreated non structural framing in non load bearing walls. It is no wonder rules like this caused the NZBIA (New Zealand Building Industry Authority) a Government owned entity to go bankrupt and overnight emerge as a new agency with the same staff to avoid getting sued by all and sundry. This also lead to the end of Private Certifiers as they could not get insurance to cover any 'mistakes' although there are still one or two companies contracted to individual local councils with the council covering the insurance.

[Rob Beale]

This graphic shows the pattern of the earthquake and aftershocks in Christchurch since Saturday morning:

http://www.christchurchquakemap.co.nz

The damage estimate has been doubled to NZ$4 billion today.
The aftershocks are causing further damage with cracks opening wider.

They have already started demolition of some of the 500 damaged buildings in the central city. Some will be saved and strengthened, but many will not.

Half the Building section from my work headed south today to help out with the assessments in Christchurch - they had to do the same job in Gisborne 2 1/2 years ago.

Rob