Ever get that feeling of quake deja vu?

Monday was the provincial anniversary holiday in Wellington, New Zealand. Kind of cool – the provinces were abolished in 1876, but we still get the holiday.

Around 4 pm the house began shaking – slowly at first and then quite violently. We get a lot of small quakes. This wasn’t one of them. In fact, it seemed up there with last year’s big quakes.

The science behind it is fascinating. New Zealand has an automated seismic network that publishes estimated figures to the internet in near-real time. The first official figures – calculated by the duty seismologist – were available within fifteen minutes, with a final refined value just over an hour afterwards. This quake, at magnitude 6.2 and with an epicentre near Eketahuna in the Wairarapa, was classified ‘severe’. It was 33 km deep – felt widely, but not so destructive as the shallow quakes that hit Christchurch in 2010-11 and Wellington in 2013. It occurred in the Pacific plate subduction zone, where the plate is being driven down by the Indo-Australian plate riding up over it. It’s no coincidence that this is right under New Zealand – the islands are a product of that collision.

Gollum in Wellington airport passenger terminal - a marvellous example of the model-maker's art.

I don’t have a photo of the Wellington airport eagles, but this is Gollum – taken last year – near the model that fell into the foodcourt. Click to enlarge.

Where I live the ‘felt intensity’ was at the high end of V on the Modified Mercalli scale. Damage around Wellington included the Weta workshop model of a Hobbit eagle  in the airport terminal, which crashed into the food-court. It was worse across the lower North Island in centres like Palmerston North. Fortunately nobody was killed or hurt.

Quakes have been on the rise in New Zealand lately. Archaeological work reveals that quakes cluster in decades-long patterns. The late twentieth century was one of the calmer periods. And now it looks as if we’re back in the action again. Christchurch, alas, may have simply been the beginning. Are they linked? Possibly. Certainly a quake in one area can increase stresses in a fault nearby that’s already under tension. But there also seems to be a general process of rising and falling activity.

The Christ Church Cathedral - icon of a city for nearly 150 years and the raison d;'etre for its founding in 1850. Now a ruin, due to be demolished.

The Christ Church Cathedral, Christchurch – photo I took in early 2013. Click to enlarge.

Best case is it will settle down. Worst case – well, there is a disturbing precedent from the fifteenth century, where a succession of massive quakes estimated at magnitude 8+ tore along the length of the country over just a few decades. One of them, circa 1460, struck just south of Wellington and filled in one of the two harbour entrances, the Te Awa-a-tia channel. Motukairangi island – modern Miramar – became a peninsula and the water within its hills swampy terrain. Peter Jackson’s studio is built on the uplifted land.

It's all in an ordinary industrial-style street.

Warehouses opposite Peter Jackson’s Park Road headquarters, Miramar – under water until 1460. Click to enlarge.

Maori named the quake Haowhenua (‘the land destroyer’). The evidence is still visible as the flat land of Miramar and the Wellington airport flats – and as beach lines at Turakirae Head. The name seemed a puzzle – a ‘land destroyer’ that produced uplift? Then archaeologists discovered evidence of 10-metre tsunamis at the same time.

The question is not ‘if’ this will happen again – but ‘when’. New Zealand has many fault lines – the largest is the Alpine Fault, which moves about every 300 years and generates quakes of magnitude 8+. We are due for one, statistically, within 50 years. Recent studies point to the existence of other large faults each side of the South Island. They are still being researched. Scary? No.  We have to accept the reality as it unfolds – and be prepared.

Do you live in an earthquake zone? If not, what natural disasters do you face?

Copyright © Matthew Wright 2014

Coming up: More writing tips, science geekery and humor. But hopefully not more quakes. For a while, anyway.

Mindless parking warden droogery in a quake-hit city

I posted last week about the way central Wellington had quietened after the July earthquake.

The dis-assembled crane in Luke's Lane - filling the lane - with the teetering lift shaft and 30-ton slab atop visible behind, propped up by another crane. Funny, why haven't the parking wardens ticketed the crane?

The dis-assembled crane in Luke’s Lane – filling the lane – with the teetering lift shaft and 30-ton slab atop visible behind, near the boom of another crane. Click to enlarge.

I think it was largely because the two largest central city parking buildings had been shut down – and parking in the streets is a lottery in the face of the Wellington City Council’s parking enforcers –  whose mind set, to me, was summed up when they deployed a spy car whose occupants intimidated motorists and issued tickets to drivers for ‘parking offences’ while they were actually on the road, waiting to turn left.

An earthquake emergency, it seems, makes no difference. Here are photos I took on Monday of Luke’s Lane, where an external lift shaft adjacent to one of the parking buildings was left unsafe in the 6.5 magnitude July quake. The 6.6 magnitude shake of Friday 16 August finished the job; it was at high risk of collapse, urgent demolition indicated. One of the biggest mobile cranes in the country was brought up from the South Island – with the help of 10 flatbed trailers and prime-movers – to remove a 30-ton slab of concrete at the top of the collapsing shaft, as the first stage of the demolition process.

Meanwhile a security company was asked to keep the public out of the lane over the weekend. While they were doing it, the Council’s parking enforcers ticketed their vehicles.

Man, that crane is one big sucker.

Man, the boom alone fills the lane – now waiting for the rest of the crane to arrive.

The Council admitted that the incident was over the top, but you have to wonder about the corporate culture that cultivated this mind set in the first place.

What would happen if the guards weren’t there and the slab fell? You can imagine it crushing some passing pedestrian – and the corpse being found next day with infringement notice taped to the forehead for loitering in a legal roadway.

Reducto ad absurdium? Maybe.

Copyright © Matthew Wright 2013

Wellington struck by more severe quakes – 16 August

As I write at 5.30 pm, my desk is rocking to three quakes in quick succession, the largest at magnitude 6.3. These are just the latest in a string that have hammered my city, Wellington in a few hectic hours this afternoon, just a month after another swarm that, we were all hoping, might be over.

Soon after the biggest – a 6.6 magnitude shock – swept over the city at 2.31 pm, the streets were filled with cars and people, getting out of town. Here’s a photo I took with my phone looking across to Parliament buildings, at the base of Molesworth street.

Pedestrians and cars at the bottom of Molesworth Street, Wellington, after the magnitude 6.6 shock of 16 August. Aftershocks up to 5+ magnitude were still rolling in when I took this.

Pedestrians and cars in unusual number at the bottom of Molesworth Street, Wellington, after the magnitude 6.6 shock of 16 August. Aftershocks up to 5+ magnitude were still rolling in when I took this.

Really, of course, we have to think of these quakes as a single large event – one with punctuated movements. What’s more, there have been other quakes around the country, likely triggered by the latest re-eruption. The ones rocking Wellington are all centred on a fault line under Cook Strait, near the South Island town of Seddon – which has taken a severe hammering.

I’d like to extend a very warm and grateful thanks to all those who got in touch with me, within a few minutes of the news spreading – and from as far away as the US – to ask how things were going. I very much appreciate your kind thoughts – thank you.

There are no injuries reported. More soon.

Copyright © Matthew Wright 2013

Thoughts on a quietening city after earthquakes

I like Wellington, as a city. It is a compact place, a Saturday evening stroll through the café district an exciting wash of colour, people, smells and sound. Yet since a wave of earthquakes began sweeping over my city, nearly three weeks ago, the city centre is quiet.

Courtenay Place, Wellington 10 August 2013. I took this hand-held with my SLR, exposure time 1/6 second, ISO rating of 800. Hand held on a sixth-second exposure time. Just saying.

Courtenay Place, Wellington 10 August 2013. I took this hand-held with my SLR, exposure time 1/6 second, ISO rating of 800. Hand held on a sixth-second exposure time. Just saying.

Normally these streets would be way more crowded on a Saturday evening. Even the opening of ‘New Zealand’s Got Talent’ across the road didn’t do more than make that side of the street look normal for a Saturday night.

I took this with my phone - quality's not quite up to SLR standard.

I took this with my phone – quality’s not quite up to SLR standard.

I don’t think it’s worry about another quake. Our seismologists are good; the risk’s low.  People are philosophical about the risks and nobody I’ve spoken to is worried. No, that’s not the problem. I suspect a large part of it is the fact that half the parking buildings are closed. Other parking building owners have elevated prices to ‘highway robbery’ level in response.

Parking on the street is suicidal in the face of a vicious guilt-on-existence Council parking enforcement system – and you don’t have to be in a carpark to be ticketed. For a while they had an enforcement spy car roaming the street photographing drivers and ticketing people that included one motorist waiting to turn. I am not joking, it got to court. The Council lost, and the incident did nothing for their repute.

Another phone picture. I wonder about this building. The upper floors are a timber-frame add-on, which to me says that in a really big quake they'll perform differently from the reinforced concrete structure below.

Another phone picture. I wonder about this building. The upper floors are a timber-frame add-on, which to me says that in a really big quake they’ll perform differently from the reinforced concrete structure below.

Elsewhere, a few buildings are empty in the face of structural cracking and safety concerns. But the main new look is the profusion of bucket cranes with glaziers atop them, replacing broken windows.  I thought I’d share a few images I took.  I used my phone, so they’re not quite up to SLR standard. But hey…

Apart from the parking difficulty, people are philosophical, cheerful – quakes are part of life, sure. But not something to get wound up about. It wasn’t the ‘big one’. And it’s been a useful wake-up call. Next time, we’ll be better prepared.

Copyright © Matthew Wright 2013

A few quick glimpses of the Wellington quake

I had the chance to take a few photos of damage in central Wellington today after the 6.5 magnitude quake that struck at 5.09 pm on 21 July.

I used to drink in the pub at the bottom of this building. Now cordoned off...

I used to drink in the pub on the ground floor. Note the damage between the buildings.

Broken windows on Featherston Street.

Broken windows on Featherston Street.

There were lots of these signs about.

There were lots of these signs.

There were lots of orange cones around. Possibly a proportion of the world supply. The new 'look, I have been upgraded to Cyber status' statue of Katherine Mansfield had a new hat.

Cyber Katherine Mansfield had a new hat.

And Civic Assurance House, on The Terrace, had a massive crack down one side.

This looks kind of serious.

This looks kind of serious.

St Andrews On The Terrace was closed because of doubts about the building site next door – which also led to nearby Bolton Street being closed off to pedestrians.

Wright_BoltonStreet

The New Zealand Geological and Nuclear Sciences department can’t rule out more quakes of the same size. Or that they might tension the main Wellington fault – likely to cause the ‘big one’.

We’ll see. Fingers crossed.

Copyright © Matthew Wright 2013

Wellington quakes: how do you react in a crisis?

New Zealand’s capital city, Wellington, woke this Monday morning to chaos after being shaken by 230 earthquakes in a 72 hour period, including a 6.5 magnitude quake at 5.09 pm on Sunday that lasted more than 20 seconds and sent masonry and glass showering into some streets.

The USGS reported it as 6.9. Local GNS scientists measured it at 6.5 – our seismic network is a fantastic bit of technology that reports ‘first draft’ results to the web in real time. The energy released was still equal to about 20,000,000 tons of TNT. That’s about half as much again as the maximum yield of a US B-83 nuclear weapon. Nature, let’s face it, can dwarf human endeavour.

The State Insurance building of 1940, with the help of the GIMP 'cartoonify' filter and some other adjustments. Now, apparently, it is on a super-earth with thick air and maybe a touch of iodine in the atmosphere.

The State Insurance building of 1940, central Wellington – a photo I took and dealt to with the help of the GIMP ‘cartoonify’ filter and some other adjustments.

In another demonstration of nature’s reality, GNS scientists initially pinned the quakes to a particular known fault line, but now report that two separate tectonic events are happening – a sideways plate movement entering the mix. James Watt once insisted that nature could be tamed, if we could but find the weak point. Actually, it doesn’t have any.

The quake was centred 58 km from Wellington. Luckily. Our house rocked and rattled. My computer bounced on the desk – not good news for hard drives – while I grabbed a glass I had sitting nearby to stop it skittering. In another room my wife grabbed the TV set to stop it falling. I wasn’t afraid of the roof coming in – we live in a wood-frame building; they twist and flex, but don’t collapse unless they quake has a felt intensity of X or XI. And it could have been worse. A LOT worse.

The quake happened just on sunset and we were rocked by aftershocks during the night, enough to wake us up. Today it’s a grey Monday, and trains are out while lines are inspected, engineers are looking over buildings – streets are cordoned off. Part of the problem is that large parts of downtown Wellington are on reclaimed land. They include the railway station. It looks like masonry. Actually it’s steel-frame and concrete. When engineers developed it back in the early 1930s, they drew on Japanese expertise to help the quake-proofing.

My first effort to abstract at 18mm focal length.

Te Papa Tongarewa – New Zealand’s national museum, one of the largest buildings in the Southern Hemisphere, is built on reclaimed land but quake-proofed via a unique base isolation system developed right here in New Zealand.

The quake swarm – so far – hasn’t constituted the ‘big one’ that might kill 1500 or more in downtown Wellington alone if it occurred in office hours. Power, water and essential services are still on. Had the epicentre of Sunday’s quake been closer to the city, it would have suffered similar damage to Christchurch.

It’s a warning – a wake-up call. The major faults near Wellington haven’t ruptured.

And it leads me to a couple of questions. One of the best resources a writer has – their food and drink – is their own experience. That’s true for all writing, but especially fiction. Self-analysis becomes a habit. For me, this quake wasn’t a major; I’ve faced worse quakes, and I’ve faced worse threats to life and limb.

Still, we are not often tested by crisis.

Have you ever had to face a moment of crisis – and what did you do?

Copyright © Matthew Wright 2013

It’s earthquake season in New Zealand

We were jolted awake this morning in Wellington by a severe quake – magnitude 5.8. The intensity in our house was IV on the Modified Mercalli ‘felt intensity’ scale.

As I write this the national seismograph network is still picking up aftershocks – every few minutes. That followed Friday’s succession of jolts which included a 5.7 magnitude shock – felt intensity in Wellington, again, was IV. They are from a fault complex in the northern South Island, near the town of Seddon – a line stretching north towards Wellington.

Demolition under way.

My photo of demolition under way, central Christchurch, January 2013.

Quakes are a fact of life in New Zealand. It’s a part of living on the joint between two crustal plates. The other issue is volcanoes, which I covered last week. Quakes are the more immediate risk. They’ve killed more Kiwis than volcanoes. The two worst were the magnitude 7.8 Hawke’s Bay quake of February 1931, which killed 258 and seriously injured over 400; and the magnitude 6.3 quake of February 2011 that killed 185.

I had to take copyright action when this book of mine was infringed.

Cover of my book on the Hawke;’s Bay quake of 1931 – now out of print, alas.

A word of explanation . The ‘magnitude’ – what used to be the Richter scale – is a measure of energy. What counts on human level is ‘felt intensity’, a subjective measure of the energy delivered to a particular place. That varies, depending on the ground the shock wave has to travel through. In the case of the lethal Christchurch quake, bedrock reflected some of the waves back under Christchurch city, where the felt intensity was VIII – ”destructive’ to IX – ‘violent’. Peak ground accelerations were estimated at up to two gravities (19.4 m/sec/sec).

None of these came close to the quakes that shattered infant Wellington in 1848 and 1855. After the 1848 shock one settler observed that : ‘Only 1 bakers oven was left intact . . . A brick wall fell and killed Sgt. Lovell and 2 children. Medical hall kept by Dr Dorset became a scene to be imagined with bare shelves and the contents broken and badly mixed . . . A number of land slips occurred on the wooded hills between Wellington and Wairarapa and in one instance a house was shaken off the piles supporting it.

This picture of post-quake Napier isn't well known; it is from my collection and was published for the first time in the 2006 edition of my book Quake- Hawke's Bay 1931.

This picture of post-1931 quake Napier isn’t well known; it is from my collection and was published for the first time in the 2006 edition of my book ‘Quake- Hawke’s Bay 1931′. Figure facing camera is my grandfather.

Some settlers blamed poor mortar. ‘Sand and water is not very sticky,’ Charlotte Godley explained in a letter to her mother. The quake was centred on the Wairau Valley and later estimated to have a magnitude of 7.1, with a strength in Wellington of about VIII on the Modified Mercalli Scale. Wellington swayed to another tremor in May 1850.

The proverbial ‘big one’ hit in late January 1855. This was catastrophic, a major failure of the Wairarapa fault with an estimated magnitude of 8.1 or 8.2, and a peak felt intensity in Wellington of X. Destruction spread from Wellington to Wanganui, and the quake was felt as far north as Wairoa. The shelved land brought up by this quake is still visible today – in fact, roads run directly along the edge of it.

Two quakes in quick succession like that was unprecedented,

The frightening part is that some seismologists theorise they were linked. What happens, the theory goes, is that a rupture of one fault sets up tensions in adjoining rocks – setting up the next fault to break a little later.

There has been suggestion that the Christchurch quake swarm that began in September 2010 and continued into 2013 – effectively shaking the city to pieces, slo-mo style – was set up by a massive quake that hit Fijordland in 2007. As for the current quakes near Seddon…well, they’re at the other end of the Christchurch complex and…uh…the next one up are the two big Wellington faults.

Scientifically speaking, the jury’s out, but I’d hate to find out the theory’s right the hard way.

Copyright © Matthew Wright 2013