The Eye of the Fish

Maximus
March 1, 2010

Earthquakes and Tsunamis

One side of the Pacific plate: horrificly large earthquake. Hundreds dead, thousands homeless, yet again buildings destroyed. We’re lucky it wasn’t us.

On the other side of the plate sits New Zealand. And, let’s be honest, a pitifully small tsunami – yes, we’re extremely happy not to have been swept away by the waves, but really, truthfully and honestly: Civil Defense grossly over-reacted, didn’t it?

While on the one hand it’s a great opportunity for the people in yellow hi-vis jackets to fly around in a helicopter, telling people to stay off the beaches and putting tourist cruise liners out to sea, I have this sneaking suspicion that every time Civil Defense do this to such a degree, we’re all going to get a lot more complacent. With Wellington having suffered the ignomy of a 10cm high ‘storm surge’ that barely stirred up the sediment on the sea bed, to me the only decent response seems to have been to have gone surfing (yes, the water was lovely, thank you for asking). It seems that someone needs to brush up on their Physics 101, where amplitude is going to be reduced at a proportional distance from the epi-centre as energy disappates dissipates (well, yes, that someone brushing up could well be me, feel free to correct me if I’ve got it wrong). The question has to be asked – are we taking this Tsunami stuff too seriously?

But what if the tables are turned? There’s some apparent evidence (and completely logical too) that events on one side of the Pacific plate are followed by reactions on the other extremity. Wellington is – vastly – overdue for a massive earthquake of similar proportions, and if it occurs here we had really better be ready. And Chile can get our backwash instead. And here, we seem to be very slowly, extremely slowly, looking at how many of our buildings we should knock down before they fall down.

Ok, so this small brick shed, of unknown parentage, lonely in the central city, may be nothing much, but are we acting fast enough? The notice stuck to the window says that the owners have until 2024 to either strengthen or demolish it. 2024? 2024 !!! Doesn’t really seem fast enough to me… The question has to be asked – are we taking this Earthquake stuff seriously enough?

Tom
1 - 03 - 10

“Civil Defense grossly over-reacted, didn’t it?”

No, no, NO! Until the Tsunami had begun to hit NZ sensors, there was no way to be sure that it wouldn’t be bigger and more dangerous. In those circumstance, the responsible thing to do is to apply the precautionary principle. Once the local effects were being detected and it was clear that there would be little if any danger beyond the high tide mark, the warnings appear to have been downgraded to something like “Don’t go messing around in boats, but don’t run for the hills either.

As it happened, at Wellington the water level only just got higher than a normal high tide (http://img158.yfrog.com/i/1r6jq.jpg/), but there’s no way I would have gone down to check until it was very clear that there was no danger.

Honeywood
1 - 03 - 10

Dissipates. There. You asked to be corrected.

Now imagine this scenario: Civil Defense runs the numbers (after all, they’ve done Physics 101) and calculates that we will receive a ‘pitifully small tsunami”, tells us all not to worry, go to the beach, run the half-marathon around the bays, strip off for a photo at Breaker Bay; she’ll be right. The tsunami (having never being to university) rolls across the Pacific, hitting any number of undersea mountain ranges, builds and builds until it crashes mightily up and down the east coast of our fair isles, wiping out thousands of the complacent. In whose direction would the collective finger be pointed? It is the job of Civil Defence to be cautious and our job to pay attention to them. The tsunami that hit Samoa wasn’t that high but it sure was long. That’s where the damage comes. Many people have died standing too close to the water’s edge in Napier and being swallowed up by a freak wave. It does happen.

With regard to the fifteen year earthquake notice, the WCC is giving all owners of unstrengthened buildings plenty of time to do something about it. Some property owners would say, not enough time. Reducing the timeframe to a few years would make many buildings uneconomic and property values would crash. The WCC is wisely applying this rule consistently – are you suggesting that they should look at those buildings built out of brick, or are sheds, or owned by churches and give them less notice?

As to why we should take a tsunami more seriously than an earthquake (which, I think, was the point of your post), earthquakes are notoriously hard to predict; tsunamis a little easier, once the earthquake has happened. And remember, this was one of the largest earthquakes ever recorded. It’s easy for a fish to be complacent but how would you breathe if you were tossed high on Hataitai?

Maximus
1 - 03 - 10

Tom, Honeywood, thanks for the feedback. Dissipates, of course.

I’m sure you’re right, but on the other hand, I suspect that after this weekend’s non-event, more people are just going to shrug off the warnings next time. The Boy Who Cried Wolf, and all that. Indeed, yes, how do we know it is a large wolf until it bites us on the bum…. but nonetheless, if every time they cry wolf and just a puppy runs out…. then its not surprising that people just want to pat it.

The answer, presumably, is that more feedback from underwater sensors may give more accurate information next time. My understanding is that NZ doesn’t really have much in the way of sensors – but the US does, in Hawaii, where the undersea coastal profile is far more condusive to tsunami than our more abrupt continental shelf. The tsunami that happened in Samoa was large because the earthquake epicentre was so close. The really serious tsunami (200,000 dead) in Aceh province in 2006 was enormous, not the least because of the undersea earthquake occurring directly off the coast, and the trapping of water in a narrow funnel where the bay narrowed. That’s a huge degree different from the situation here, where we have an entire half the globe full of water between us and them, and the ripple from the puddle has clearly gone wide and disappated / dissipated.

My comment re the Earthquakes is that really, if human life is to be saved and buildings stopped from falling down, then a 14 year gap between notice and rectification is asking for trouble. If there is a large earthquake, then these buildings really will fall down, and potentially kill people. At present the Earthquake Strengthening fund from the WCC is something like a pitiful $25,000 per project (although that would be more than enough for this shed). If the Council is serious about saving heritage as well as life, then the fund should be drastically increased.

m-d
1 - 03 - 10

You’re not alone in crying “crying wolf”: http://www.stuff.co.nz/national/blogs/on-the-house/3389257/The-boy-who-cried-tsunami

I have to admit taking the kids down to the Sunday market as usual – but only after it had become patently obvious that the overt breathlessness of the media was just a pitiful attempt at hype. Nevertheless, I think that the path taken by the CD was appropriate given the unknowns involved.

It was the first time that i haven’t seen a long queue for fresh fish from the boats that tie up to the wharf though…

Regarding EQ building codes and timelines (which seems to me to be a quite different issue) – a point in your favour is that the earthquake in Chile released roughly 500 times greater force than that in Haiti. Loss of life estimates are approx. 200000 in the former, and at the moment about 700 in the latter. A good case for regulated building standards (or has it more to do with the geology of the different sites)…?

m-d
1 - 03 - 10

Actually – the forces released in the Chile eq were twice as deep into the earth’s crust (22km) than that at Haiti (10km), which has obviously had some impact on the damage. Not sure what that mens for surface disruption at either site given the huge difference in power though… Someone who actually did physics101 might be able to help me out there?

m-d
1 - 03 - 10

It seems it is a combination of both geology and building regs – the very next article that appeared in my feed aggregator fortuitously answers all my questions: http://www.guardian.co.uk/world/2010/mar/01/chile-earthquake-resistant-design

Maximus
1 - 03 - 10

md – thanks for the link – i hadn’t seen the bit from Espinor. But then I went surfing on Stuff, and bought a paper (the same info, but always so much more authoritive when it’s actually printed, don’t you think?) and found these two nicely contrasting reports:

http://www.stuff.co.nz/national/3387016/Sightseers-and-swimmers-refuse-to-leave-the-beach
nice quotes – “Two women having coffee on Milford Beach said they had a good vantage point and another woman about to head out on a walk to Takapuna Beach said she had her flippers.”
and this: ” Two Dogs coffee caravan owner Mike Duffy continued trading through the morning, but had been warned of the danger by police, Civil Defence and a helicopter flying overhead with a loudspeaker. The beach was largely empty but those there were not concerned. “It’s just a joke more than anything,” he said. ”

Civil Defence Minister John Carter agreed the public’s response was largely good, but criticised those who went to the coast for a better view. “They are the makers of their own demise if anything does go wrong,” Mr Parker said. “Unfortunately, we always get the odd person who doesn’t appreciate the risk,” …”If you go down to the water, it might be the last thing you ever see.”

and this one:

http://www.stuff.co.nz/national/3387024/Diver-swept-away-by-wall-of-water
“Leon Mickelson was fishing for paua at Red Rock Beach in Hawke’s Bay when he was swamped by a metre-high surge of water, followed by two more waves. He had no idea a tsunami alert had been issued.
“This wall of water just hit me. I was getting tumbled across all the rocks, it was unbelievable. The force was just unstoppable. There was no way you could fight it, you just had to roll with it.”
The water then sucked him 20 metres out into the ocean, bouncing over rocks. “It was like being in a washing machine. It just completely and utterly caught us out.”

m-d
1 - 03 - 10

“printed” you say – what’s that? – some kind of archaic process whereby a large amount of energy is expended in turning natural resources into a base and pressing toxic chemicals into it so that information can be shared in a completely 1-way ‘tansaction’ (which you do actually have to pay for).

Wouldn’t touch the stuff. Google Reader is my friend (hence the Guardian link)…

m-d
1 - 03 - 10

Ps to the above – it would be great if we could get a feed to the comments for eotf also, rather than just the new posts…

Alan Wylde
1 - 03 - 10

The amplitude was not negligible in Japan which is much further away. Simple physics does not work in this example!

Maximus
1 - 03 - 10

Tell you what – an iPhone version of the site wouldn’t half go down a treat too. Poneke’s site has got a sweet new ticker that spits out text to the mobile world. Very nice – and as fast as a jogger in a no swim zone. If you could do that Philip, I’d be well chuffed!

Alan Wylde
1 - 03 - 10

For a mere pc user this site is very badly behaved!

Maximus
1 - 03 - 10

Alan, ‘mere pc user’ ? I’m tempted to say “Get a Mac” but I’ll resist the temptation.
What seems to be the problem?
Have a seat.
Lie back and close your eyes.
There, now what seems to be the problem…?

Mike
1 - 03 - 10

The strange thing is that council won’t give us a permit to demolish it!!!!!!!!!!!!!!

Maximus
1 - 03 - 10

The council won’t give you a permit to demolish ? You’re talking about the old Elim shed?
Well, you’ve got 14 years or so to get that resolved. In the mean time, tell us more about it.
Is it old? My guess would be 1890 – 1910 ?
Is it historic? Must have been a shed for something interesting once upon a time.
Is it interesting inside? Cos apart from a pretty plain blank wall outside, it looks pretty dull.
Will the Council give you $25 k to restore it? Cos if not, then…..

But most importantly – given that anything proposed as a replacement should be better than what exists, what are you proposing to do with the site? Big new Elim gospel church? Hall for singing and dancing? They get a tick from me. But if its a carpark – naaa, thumbs down…

Philip
1 - 03 - 10

M-D – the comments feed is over here: http://feeds.feedburner.com/CommentsForEyeOfTheFish

Maximus
2 - 03 - 10

for those that want to watch the ripple effect in action, there is a great little movie on Wiki, of the Samoan tsunami effect across the Pacific.
http://en.wikipedia.org/wiki/File:Samoa_tsunami_animation_20090929_samoa_a.ogv

m-d
2 - 03 - 10

Thanks Philip!

Philonz
2 - 03 - 10

There was damage in NZ after a Tsunami in 1960 caused by a quake in Chile. I for one will continue to heed the warnings of CD and will have no sympathy for the clowns who go surfing in spite of the danger. It really isn’t the hardest thing in the world to stay away from the coast for ONE day.

Quaker
3 - 03 - 10

“council won’t give us a permit to demolish it!”

Well, a Resource Consent is required to create open space in the city, or to create a new building in its place. The council _could_ give you a consent for that, I guess, but they’d have to be convinced that whatever replaces it is going to be good. For instance: not a carpark.

Maximus
4 - 03 - 10

There’s a report that the Tugboat Restaurant suffered damage from ‘tidal surges’ on Monday.
http://www.stuff.co.nz/dominion-post/local/3397231/Tug-gangway-now-shipshape

Although some may argue that it is a pity the whole ugly boat didn’t sink as well, is this actually delayed tsunami damage?

Anyway: Stuff website also reports :BREAKING NEWS
Tsunami warning issued for part of Chilean coast after huge aftershock … More soon

Hmmmmm. Not issuing tsunami warnings here, I see.

Honeywood
4 - 03 - 10

be careful Maximus… when I once made a passing reference to the tugboat restaurant in an article I wrote the owner rang me up and physically threatened me

Maximus
4 - 03 - 10

They threatened to break your legs didn’t they? No fear here, just a very slippery tale…

It is a bit of a tragedy really, isn’t it. The food’s awful, that gangplank is clunky, and there’s always a faint smell of cat-pee or something from the old carpets. Plus the view both in and out is crap. However, I do quite like the idea of people living on boats, and restaurants on boats, and all sorts of activities and things on boats. It’s a pity they sent the old King Kong boat to the bottom of the sea, as that would have made a nice old rig quietly aging at the seaside. I’d argue that we need another 100 boats out in the harbour, rather than getting rid of this one.

Honeywood
5 - 03 - 10

Actually he rang up and said “you can’t write about my business without my permission. I’m going to come round there and punch your lights out”. I complained to the police who didn’t seem to take it seriously. They said “has he hit you yet? No? Come back when he has”