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6.3 Magnitude Earthquake Hits New Zealand
Topic Started: February 22 2011, 11:20 AM (658 Views)
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A 6.3 magnitude quake in the New Zealand city of Christchurch has left at least 65 people dead and hundreds more trapped in collapsed buildings.

The strongest tremor, which was measured at a magnitude of 6.3, struck at a shallow depth of just four kilometres, at 12:51pm local time (midnight Irish time). There had been two smaller tremors in the morning, and in the hours that followed there were 12 aftershocks, measuring up to 5.9 in magnitude. It is the second major quake to hit the city in six months.

Local television showed bodies being pulled out of rubble strewn around the city centre. People have gathered in the middle of parks across the city, seeking safety from the danger of aftershocks Two buses were crushed by falling buildings and a local youth hostel imploded. Rescue and recovery efforts are continuing.

The Department of Foreign Affairs has said it is attempting to find out whether any of the 1,000 Irish people living in the city have been affected by the quake.

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6.3 quake in Christchurch, NZ, 65 deaths reported

Note aftershocks ranging from 5.6 to 4.5 have also been felt in the last few hours.

http://wattsupwiththat.com/2011/02/22/6-3-quake-in-christchurch-nz-65-deaths-reported/
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It is also being reported that the quake caused some 30 million tons of ice to break off from New Zealand’s biggest glacier. Tour guides at the Tasman Glacier in the Southern Alps say the quake caused the ice to “calve” from the glacier, forming icebergs in the terminal lake.
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'Fairly violent' 5.3 earthquake rocks Christchurch
By Paul Harper
8:10 AM Tuesday May 10, 2011

A 5.3 magnitude earthquake has rocked Christchurch early this morning, GNS Science reports.

The aftershock was centred 20km west of Christchurch, at a depth of 15km, striking the city at 3.04am.

GNS Science said the quake was "widely felt around Canterbury", with many Cantabrians reporting the jolt was "slightly damaging".

The aftershock is the second largest to strike following the devastating 6.3 magnitude earthquake on February 22.

It was also the 25th earthquake Canterbury has had measuring five or more on the Richter scale since the 7.1 magnitude earthquake on September 4.

Prime Minister John Key said the quake has not caused any further considerable damage, but it "gnaws away at the confidence of Cantabrians who want this to end and for things to return to normality".

Mr Key is due to visit the city on Thursday.

A Fire Service southern communications spokesperson said there were no callouts following the quake.

Police said the only calls they had were from staff wondering if they needed to come to work.

New Zealand Herald reporter Jarrod Booker said the quake was "fairly violent".

"It gave the house a good shake," he said. "It was noticeably larger than previous aftershocks."

On social networking site Twitter Cantabrians shared their experience of the jolt.

"That #eqnz is close to home - no wonder it felt so dam powerful! and broke the window," Deon Swiggs tweeted.

"The Sky TV broadcast of the Liverpool FC game doesn't start until 6.55am. Up too early! Should have set that shake for later," Bob Hall tweeted.

"I wonder if The Grand Chancellor Hotel is still standing?" David Jones wrote.

There is no visible change to the Hotel Grand Chancellor this morning. The 26-storey building is still on a lean awaiting demolition.

Power remained on throughout the tremor.

GNS Science seismologist Caroline Ashenden said it was definitely one of the bigger aftershocks, but was not unexpected.

"We forecasted between zero and two aftershocks greater than 5 in the month between the 19th of April and 19th of May and this is the second one we've had," she said.

Newstalk ZB's Jo Scott, said the constant shaking doesn't get any easier, especially when they come in the middle of the night.

"We've had a total now of 5490 aftershocks and it's not nice. It's definitely something that is hard to deal with. It's very hard for people in Christchurch, especially when they're woken."

Canterbury residents have told Newstalk ZB they feel exhausted and under siege.

"You feel like soldiers, you're hanging in there but people are only human and they do break down," one caller said.

The aftershock has been followed this morning by a 3.4 magnitude quake at 6.06am, centred 10km southwest of Christchurch at a depth of 5km.

The 5.3 shake measured 6 on the Mercalli scale which measures ground shaking. That means it would have been difficult to stand, items are likely to fall off shelves and there will be plaster damage to some houses.
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Powerful earthquakes rock Christchurch......Last updated 20:45 13/06/2011.

GNS Science is warning of more aftershocks in coming days as thousands of people face a night without power after magnitude 6.0 and 5.5 earthquakes rocked Christchurch.

The magnitude 5.5 quake struck at 1pm, 10 kilometres east of Christchurch at Taylor's Mistake beach, at a depth of 11 kilometres, and sent people scrambling for cover. It was followed at 2.20pm by a more powerful magnitude 6 quake, centred 10 kilometres southeast of the city and 9km underground.

At least 40 people were injured in the earthquakes today, including two who were injured seriously, Radio New Zealand reported. At least ten people were taken to Christchurch Hospital with injuries due to falling building material after the 1pm quake.

Other residents from the devastated city cried in the streets and hugged their children.

Police said there had been no deaths.

Lines company Orion said 20,000 homes and businesses in eastern Christchurch were without power at 7pm. It was unlikely power would be restored to them overnight.

The company said crews were making good progress in restoring electricity to the city. The earthquakes had initially knocked out power to 56,000 homes and business.

Canterbury District Health Board advised that all water must now be boiled and residents should use chemical toilets or portaloos.

Christchurch City Council has set up a welfare centre at Cowles Stadium, where beds are available, for people who have had to leave their homes.

The quakes are the latest in a series of dozens of aftershocks to hit Canterbury following the devastating February 22 earthquake, where 182 people died, and a damaging magnitude 7.1 earthquake last September. The February 22 quake measured magnitude 6.3 and left 100,000 homes damaged - 10,000 beyond repair.

Christchurch's CBD was left in ruins, with 900 buildings - many in what has become known as the 'red zone' - expected to be demolished.

PM: 'WE STAND BESIDE THEM'

"We stand beside them, we are committed to rebuilding the city," Key said.

Key said Christchurch people were stoic people would regroup.

Key said Mayor Bob Parker was considering whether to declare a state of local civil defence emergency but the Government did not consider today's events serious enough to declare a national state of emergency.
Parker said it was "a serious situation" despite not declaring another state of emergency with power unlikely to be restored to the 50,000 who had lost it until tomorrow. The city's water infrastructure was also damaged. "Look after yourselves big time tonight," he said.

Today's quakes would "almost certainly" be considered a new event by insurer the Earthquake Commission, Key said.

The earthquakes were another blow to Christchurch residents, who found them frightening and upsetting.

"Quite frankly I think they're all over this and they want the sense of normality to return ... my heart really goes out to them."

It could have changed the areas that can be built on but too soon to stay.

Key said to demonstrate the significance of today's quakes, the magnitude six quake this afternoon registered an eight on the Mercalli scale which measures the intensity of earth quakes. By comparison the February 22 earthquake was a nine.

Following today's second quake, Parker said: "Thank God we had evacuated the red zone."

"We are being enveloped with dust. It is very very scary," Parker said.

Civil Defence has again set up a headquarters at the Christchurch Art Gallery where shaking was so violent those inside feared the large glass windows would burst.

As many as 50,000 homes are without power and authorities are urging residents to conserve water due to fears of further significant damage to the infrastructure.

Canterbury District Commander Dave Cliff urged residents to check on friends and neighbours, especially the elderly.

There was significant traffic congestion and drivers were told to avoid Ferry Road.

Civil Defence was setting up its headquarters in tents in Cranmer Square, near the evacuated Art Gallery.

'REJUVENATED' AFTERSHOCK ACTIVITY

GNS Science said residents could expect more aftershocks within the magnitude 4 to 5 range in the coming days due to the two latest quakes.

Today's magnitude 6.0 and 5.5 shakes were within range of forecasted aftershocks, and were centered on the coast and a short distance south of the fault that ruptured on February 22.

"These aftershocks were within the existing Canterbury aftershock zone and were within probabilities," GNS Natural Hazards Research Platform manager Kelvin Berryman said.

"This size of events is likely to produce its own aftershock sequence, therefore rejuvenating aftershock activity at least in the short term."

Scientists have said people should expect an elevated earthquake activity for many months since the magnitude 7.1 quake hit in September last year.

BUILDINGS FALL

More masonry fell from the landmark ChristChurch Catheral and there were reports of other buildings - in Lichfield St, in Latimer Square and at the corner of Stanmore Road and Worcester Street - falling down.

A house has fallen from the top of Clifton Hill into Peacock's Valley below as scores of people attempt to leave the seaside suburb of Sumner. Many residents have turned their power and water mains off before leaving the suburb which bore the brunt of today's earthquakes.

A crack through Scarborough Hill has seen the main road to Taylors Mistake cut off as emergency services fear more rockfall could destabilise other clifftop homes. One resident said the area was decimated and that damage to their homes was "far worse" than February's 6.3 magnitude quake.

Two men who had been salvaging windows from the St Johns Church in the central city were reported to have received cuts and bruises and were taken to hospital.

St John staff member Alistair Drye said the two men were okay, but shaken.

"The walls fell down around them," he said.

The church had been severely damaged in February's earthquake and was set to be demolished.

Walls around the outside of the church had "fallen and crumbled" during today's aftershocks, while the roof had collapsed onto the organ and the front of the church, he said.

The tower of Lyttelton's hiostoric Timeball Station fell in today's second quake.

Using binoculars, Lyttelton resident Peter Evans said he could see the remains of the Timeball Station from his back garden.

"You can see the tower has come down. The back roof looks like its collapsed into the building. The top of the tower has fallen off and is lying on the ground. The building has collapsed really."

Stonemason Mark Whyte was employed to take down the Timeball Station to see if it can be rebuilt. He was up a crane when the first aftershock hit. He said immediately went into Christchurch to check on other heritage buildings he is in charge of dismantling.

Asti Renaut had returned home and was chatting to a neighbour across the fence when the second earthquake struck.

"It felt like I was surfing on the lawn," she said.

Dominos Pizza assistant manager Renee Murray said Stanmore St buildings, in Christchurch, had also partially collapsed.

"All the shops have fallen down,'' she said. "Half of the roof has fallen in. They have not fully collapsed.''

Roads and bridges have been closed due to further damage and widespread liquefaction. And there have been reports of serious rock falls at Shag Rock, Boulder Bay and other coastal areas.

In the Liggins St area of Horseshoe Lake, the ground was bubbling with sand spurting out of the ground, as happened in the first two major quakes, a resident said.

EMERGENCY SERVICE RESPONSE

Canterbury police communication manager Stephen Hill said police moved to evacuate the red zone after the first quake.

A St John spokesperson said several ambulances were operating in the city and others were on standby.

Firefighters rescued two people from St John's Church in central Christchurch, fire communications spokesman Iain Lynn said.

Fire Service spokesman Dan Coward said there had been countless callouts to burst pipes, especially in the Sumner area where many locals were "freaked out".

He said fire crews were investigating a number of suspected fires and the smell of smoke in various sites around the city.

Flights have resumed in and out of Christchurch Airport but Jetstar and Qantas flights are still cancelled due to volcanic ash from the Chilean volcanic eruption.

Christchurch Airport's CEO Jim Boult said engineers have assessed the runways and terminal and there is no damage.

IMPACT WIDESPREAD

Significant rockfalls have been seen in Sumner and parts of Banks Peninsula and land and cellphone lines were down in many of the beachside suburbs and in the Heathcote Valley.

Liquefaction had been reported across the eastern suburbs and as far away as Kaiapoi, which was hard hit in the September quake.

Sirens were sounding throughout the inner city and helicopters were flying over the red zone.

Telephone networks reported lines overloading and asked users to text rather than call. Telecom, Telstra and Vodafone all reported congestion.

One Pak 'n Save Wainoni worker said items had been thrown from the shelves and the floor was littered with food and broken glass.

"It was pretty freaky. It felt like it was right under the supermarket," she said.

Sumner Supervalue supermarket is closed while staff clear fallen stock.

Residents in Beckenham and Merivale said crockery smashed and shelves were emptied.

EVACUATIONS

All staff at the Art Gallery, currently being used by earthquake and council officials, were evacuated.

Students at Burnside High, Christ's College, St Margarets, and St Andrews College, were also sent out of buildings to the safety of playing fields.

There were evacuations at Canterbury University, Westfield Riccarton mall and Pak 'n Save Wainoni.

Staff at the Canterbury Earthquake Recovery Authority have evacuated their Papanui building and won't return until a structural engineer has assessed it, a civil defence spokesman said.

Canterbury University law student Jennifer Jones was on the second floor of the university library when the quake hit. "It started off not too bad but then all the books started flying off the shelves. You've got 11 floors above you so everyone got out pretty quickly."

Riccarton mall was evacuated after the earthquake at 1pm today with reports of fallen roof tiles and raised floors in the building.

No injuries were reported as several thousand people were forced outside.

Several Westfield employees were in the building when the magnitude 6 quake struck at 2:20pm but were unhurt.

Greymouth pair Matt Adams and Crystal Graham-Hayes were shopping in Amazon when the magnitude-5.5 quake hit at 1pm.

''All the lights started shaking to the ground. I freaked out a little bit,'' Adams said.

''One of our mates [in Greymouth] texted before and said they felt it a little bit.''

The pair had not experienced a Christchurch quake before but Graham-Hayes felt they tempted fate this time.

''About ten minutes before the shakes I turned to [Adams] and said 'We haven't felt one yet' and then it happened.

''Watching everyone trying to run down the escalators that go up was a bit interesting. Everyone was pushing everyone out of the way trying to get through. Very scary.''

Configure Express Gym manager Janet Peterson said shoppers' reactions varied.

''It was a mixture. Some people were used to them but others you could see blankets being wrapped around people and people physically shaken up.''

Alena Smith, a retail assistant at fashion store Bling, had a near miss with a falling lightbulb.

''I saw a lightbulb just fall straight down in front of me. There was a bit of shattered glass.''

A spokeswoman for Westfield said the mall would not reopen today.

WITNESS ACCOUNTS

Press reporter Marc Greenhill was in Brooker Ave, Burwood, when the 6.0 struck.

He was talking to one of the residents who was trying to clean liquefaction out of his lounge from the 1pm quake when the second one struck.

"The road split down the middle and seven or eight mini geysers spurted liquefaction and water onto the road."

Within a minute the whole street was flooded and several cars were trapped.

Water levels rose above the gutter and across the pavement and up into driveways.

A woman came screaming out of her home as liquefaction silt and water poured out into gardens.

A witness near the Lyttelton Tunnel said the quake dislodged rocks from the Port Hills above, some which looked to be as big as car tyres.

Central Christchurch resident Jon Hicks said "everything come out of the fridge" during the quake.

Other items had fallen over inside his home but power and water supplies were still working as normal, he said.

Anthony Surynt was working in an electrical workshop in Sydenham, close to the CBD, when the quake hit. He says it came on really fast and lasted for about 10 to 15 seconds. "It was quite quick. I wouldn't be surprised if another building came down."

He says it didn't feel as big as the February 22 quake but compared it to the September quake. Surynt ran out of the building as soon as he felt the earthquake, fearful of all the electrical equipment in the workshop. He has now gone back to work.

Christchurch east MP Aaron Gilmore said he was just getting out of the car when the quake hit and couldn't work out what was going on.

"I could see the ground rise on the road, it was a bit freaky."

There was cracking in the wall of his North New Brighton office that hadn't been there in the last quake and more liquefaction and water.

"I was here for that last 5.5 quake and it definitely felt bigger," Gilmore said.

Lorraine Hill, who lives in Taylor's Mistake, said she was thrown out of bed by the earthquake's force.

"It was enough to throw me on the floor and have great difficulty getting up," she said.

"It's just our nerves, we haven't had one that big for so long."

Christchurch resident Amy Brown was home alone when the latest quake hit.

She said she was frightened and ran to a door frame for cover.

"It was like February. Things started to fall out of the pantry."

She urgently got in contact with her husband, and both checked on their children at school.

Meika Gale was working at Buns Bakery in Woolston when the quake hit and says some of the roof collapsed into the shop. She says some drinks fell out of the chiller but there isn't any major damage.

She says it was a "really violent shake" that lasted about 30 seconds.

Meika was preoccupied with trying to get hold of her former partner who is looking after their four-year-old daughter but phone lines are restricted.

Twitter user Nathanael Boehm said his two level house "swayed heaps". "Was up and ready to leap out a window if it started coming down.

"That would have been bloody close to a 6 magnitude quake. Heart going mental. Hope everyone ok!"

Other Twitter users also reported smashed items in their houses and car alarms being set of by the aftershock.

Richard Derham reported walking through the Arts Centre carpark and seeing "a couple of hundred cars start dancing".

QUAKES SINCE 1PM

1pm, 10km south-east of Christchurch, 11km, 5.5;

1.08pm, 10km south-east of Christchurch, 11km, 4.4;

1.28pm, 10km south-east of Christchurch, 9km, 3.4;

2.20pm, 10km south-east of Christchurch, 9km, 6.0;

2.40pm, 10km south-east of Christchurch, 10km, 4.9;

2.50pm, 10km south-east of Christchurch, 6km, 3.4;

3.08pm, 20km east of Christchurch, 8km, 3.7;

3.33pm, 20km south-east of Christchurch, 5km, 3.5;

4.10pm, 20km south-east of Christchurch, 8km, 3.5;

4.23pm, 10km south-east of Christchurch, 8km, 3.6;

4.27pm, 10km south-east of Christchurch, 8.8km, 3.3;

4.40pm, 20km south-east of Christchurch, 6km, 3.6;

4.56pm, 10km south of Christchurch, 5km, 3.5;

6.11pm, 20km south-east of Christchurch, 9km, 3.3;

6.50pm, 10km east of Christchurch, 5km, 3.0;

7.21pm, 20km south-east of Christchurch, 2.9;

7.29pm, 20km south-east of Christchurch, 3.5;

7.42pm, 20km east of Christchurch, 3.7;

7.59pm, 20km south-east of Christchurch, 3.2;

8.28pm, 20km sou-east of Christchurch, 4.0;

8.45pm, 20km south-east of Christchurch 3.4;

9.05pm, 10km south of Christchurch, 2.9;

9.52pm, 20km east of Christchurch, 2.8;

Magnitude 5.5 earthquake footage:

Aftershock on Camera | Christchurch Earthquake | 5.5, 11 km deep, Mon, Jun 13 2011 1:00 pm ....Video link .... http://youtu.be/01NK8zrOuyQ

St johns latimer square christchurch 6.0quake 13.06.11 ...Video link ...... http://youtu.be/aPlhah46EkM

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Liquefaction and sinkhole following the Christchurch 6.0 today


More info and videos Link ........ http://thecontrail.com/forum/topics/christchurch-shaken-by-55-and
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NZ Herald....4:19 PM Tuesday Jun 14, 2011

Christchurch: latest updates Link ...... http://www.nzherald.co.nz/nz/news/article.cfm?c_id=1&objectid=10732090
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Christchurch shaken by another new fault line

15:14 14 June 2011 by Wendy Zukerman

A 6.3-magnitude earthquake shook the New Zealand city of Christchurch on Monday. It was preceded about an hour earlier by a 5.6-magnitude foreshock.

The tremors are aftershocks from the 6.3-magnitude quake that unexpectedly hit the city on 22 February.

This time, several buildings collapsed and power was disrupted. The greatest force of the quake hit areas that were already damaged, however, leaving most of the city centre unaffected.

The recent earthquakes struck only 3 kilometres south of the epicentre of February's quake. But Bill Fry, a seismologist at the Institute of Geological and Nuclear Sciences (GNS Science) in Lower Hutt, New Zealand, says they occurred on "a completely different fault line".

Since February, GNS Science has been monitoring aftershocks in the New Zealand region of Canterbury, in which Christchurch lies. These observations revealed a "distinct cluster" of aftershocks in the new region, suggesting this is a new fault line, says Fry.
Moving and shaking

"The ground motions were also quite different in the two events," he says. Most of the movement in the February quake was caused by the tectonic plates thrusting over each other, but this time, the plates were moving "from side to side". At their fastest the plates accelerated at 20 metres per second2.

According to Fry this fault line was activated by February's quake, which triggered a lot of movement in the plates.

John Townend, a seismologist at Victoria University of Wellington, New Zealand, says the recent quake could "re-energise the system" and create a new wave of aftershocks in the region. Christchurch has been trembling since February, with minor quakes shaking the town almost every day, but this is the largest aftershock yet recorded
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Monday's earthquakes 'lift risk to 30pc' Last updated 11:53 15/06/2011.

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Geovert engineering firm engineers at the top of a cliff overlooking Shag Rock at Sumner.

Christchurch mayor Bob Parker says there are no reports of damage from this morning's 5.0 tremor which rattled the quake-hit city.

The tremor, which struck at around 6.27am, was centred 20km southeast of the city at a depth of 6km.

It was followed by a 4.2 magnitude shake at 6.32am.

At a media briefing outside the Christchurch Art Gallery this morning, Parker said Christchurch quakes remained a "live event" and residents should be prepared in case of any future emergency.

People should have supplies of food and water ready, though he hoped they would not be needed again.

Police earlier said there were no reports of damage.

GNS duty scientist Gill Jolly said the 5.0 aftershock was likely from the same fault line that produced Monday's big shakes.

"On it or very very close to it - there's been a number of aftershocks in that same area."

The 6.3 and 5.7 quakes would have generated their own series of aftershocks, Jolly said.

"Every time there is a bigger quake it resets the clock," she said.

Those would now follow the general pattern of decreasing in rate and frequency over the coming days and months.

Three other aftershocks rocked the city since midnight.

CHANCE OF NEW BIG QUAKE RISES

Monday's quakes have increased the probability of another earthquake of similar size or stronger hitting Canterbury in the next year.

New calculations by GNS Science yesterday show that from today until June 15 next year there is now a 30 per cent chance of a quake of between magnitude 6.0 and 6.9 striking the Canterbury aftershock zone.

That compares with a nearly one-in-four, or 23 per cent, probability expressed last month.

The calculations show if that quake does not occur in the next month, the chance of it happening will drop back to about the 23 per cent level.

GNS Science hazards modeller Matt Gerstenberger called it a "slightly increased" risk.

"Before, we were talking about a one-in-four chance. It's now three in 10. It's an increase but it isn't a large increase," he said.

"If we do the same [yearly] calculations for a month from now, assuming there haven't been any aftershocks of over 6.0 between now and then, it's back to where it was before."

Scientists analysing Monday's quakes – yesterday upgraded to magnitude 5.6 and 6.3 – now believe they occurred on another fault 2km to 3km south of the Port Hills Fault, which generated the February 22 shake.

Seismologist Bill Fry said there had been six aftershocks of magnitude 4.0 or greater on or near this fault since February.

Like most of the quakes since September 4, they had been high in energy. However, most of the energy released on Monday was horizontal, compared with vertical on February 22.

"This contributed to the anomalously high shaking intensity of the earthquakes, as the amount of shaking is proportional to the energy released," Fry said.
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"The spatial size of the underground rupture area for the magnitude-6.3 quake was relatively small for the amount of energy released. This implies that the fault was very strong."

Visiting United States seismologist Kevin Furlong said Monday's major aftershocks had probably reduced the stress buildup around the eastern end of the Port Hills from the February 22 quake.

It was likely stress had now transferred further east and offshore, he said.

"So there will be aftershocks from this and they will likely mostly be on or near the fault that ruptured [on Monday], and also possibly further to the east, and also some to the north-northeast, as was the case after February."

He said the first quake had been a trigger for the second, with both showing almost identical movements.

"Although their locations relative to the February event are slightly different – more to the east – I think they reflect the same tectonics," he said.

"Whether we want to say they are the same fault or simply adjacent faults is really semantics to me. They are fault segments that are interacting with each other."

After such an incredible sequence of quakes, the problem now was knowing what "normal" was.

Earthquake scientists had "cut their teeth" on the behaviour of quakes from plate boundary faults such as the San Andreas in California and New Zealand's Alpine Fault but knew far less about small crustal quake sequences like this one.

"We know the plate boundary faults' history and behaviour that, say, every 300 years they do this or that. But with this type of event, we don't know what is normal for the Canterbury region," Furlong said.

"We assumed what we had up to September 4 was normal, but it appears it wasn't normal. We don't know what is the background condition that the Earth is now moving towards.

"Each earthquake sequence is unusual, this one both because of its character and observation.

"It's as well-recorded as any of this size has ever been. We are seeing things about it – things that we don't see in any other place.

"It's aspects of this that makes this [sequence] very important to science and why it's hard to be definite about how it's going to behave."

Geotech Consulting engineering geologist Mark Yetton said he had not seen any obvious surface rupture on the Port Hills from Monday's quakes.

QUAKES UPGRADE

Monday afternoon's biggest earthquake came close to outstripping the magnitude of the deadly February 22 quake.

GNS Science seismologists yesterday reclassified the 2.20pm aftershock as magnitude 6.338, just 0.005 of a magnitude smaller than February's 6.343 quake.

Their new analysis found it was significantly shallower than first thought – at a depth of 6.1 kilometres, not the originally reported 9km.

The February quake was about 5.9km deep.

The earlier shake on Monday was upgraded from 5.5 to 5.646 in magnitude and occurred at 1.01pm, about a second later than initially recorded. It was 9.2km deep rather than 11km.

GNS Science seismologist Bill Fry said the upgraded magnitudes reflected further analysis of local, regional and more distant New Zealand data. "It's quite a quick determination, but it includes a lot more data than we had for the solution yesterday," he said.

"The initial estimates of size and location were based on data received within minutes of Monday's earthquakes occurring. The revised magnitudes incorporate data from about 250 seismographs throughout New Zealand."

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CLOSE CALL: The Sumner RSA seen from the air.
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Aerial photos of Christchurch.

Link to photos ................ http://www.stuff.co.nz/national/christchurch-earthquake/photos/5138783/Aerial-photos-of-Christchurch
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Street Cam view of streets, etc


Link .......... http://eqviewer.co.nz/
Edited by Audi-Tek, June 15 2011, 08:26 PM.
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