Sunday, 20 March 2011

Predictions, earthquakes & preparedness ~ living in our changing world

The changeable nature of the world we live in makes it probable that all of us will experience disasters at some stage of our lives.  Whether they are caused by humans or by upheavals in the natural world, I'm sure most of us wish we could know of them in advance and thus avoid them. But life isn't like that.  And even in the best ordered of circumstances there are no guarantees.   

Be that as it may, a degree of informed forecasting can ease our passage considerably: accurate weather forecasting, for example, is essential for those who fish and farm, as well as making life simpler for the rest of us; forecasts of supply and demand are helpful for retailers and buyers alike, and so on.  Earthquakes are far harder to predict.  From detailed scientific study of known fault lines seismologists know much about where and how often earthquakes are likely to occur, but cannot usually predict their exact occurrence; statistics give a clear picture of averages, but this does not mean that seismic events are evenly spaced. 

Even the most carefully considered predictions are chancy things.  
Sometimes predicted events come to pass and often they don't.  Predictions that are worth taking note of are based on accumulated insight which takes into account a whole series of historical events.  This is where science can be a big help in giving us a rational base for how to prepare for and respond to these situations.  

It's natural that where science can't give us certainty that we look for other ways of divining what may happen in our world.  To give in to this sort of reading of the natural world is tempting but in my view seldom helpful.  An intuitive sense of impending disaster can be useful in prompting us to do the preparation we should be doing anyway, and while an unexplained impulse to run out from under a tree just before it's struck by lightning can be lifesaving, pronouncements about impending cataclysmic events are often productive only of panic and hysteria.  In my view they are best disregarded.  

This weekend a lot of New Zealanders, especially those living in Christchurch, have become very anxious due to a prediction that a further earthquake may occur.  This prediction has not come from seismologists or accepted 'authorities' but none the less many people have taken it seriously and become very agitated.  Will it prove to be accurate or not?  I'm not going to consider that.  What will be will be.  (See 'Later Note' below)

What I aim to provide here is a more practical perspective which may help re-balance the scales in the direction of greater calm.

I think all of us are afraid of disasters of this sort.  A serious earthquake is a serious disaster, which could kill us and even if we survive could cause ruin in our lives.  This is big stuff.  On the other hand, no one gets out of this life alive, but in the meantime we can improve our chances of being here longer and more comfortably if we are practical and apply a little science.  It's not difficult, but it does require us to apply ourselves to the task at hand.  

Some examples of disaster preparedness which we observe without thinking: when we get into our cars we put on our seatbelts - good; before we get on our bicycles we put on our helmets - good; do we answer our cell phones when we are driving?  Of course not!  We have rules and laws about all these things, which is as it should be - there's no reason to court disaster either to ourselves or those around us by neglecting these points.

Other routine examples of disaster preparedness which are very much part of our lives are: fire drills and exit points, earthquake drills (at school anyway!), life jackets, safety harnesses, poison hot-lines, aeroplane take-off safety drills, insurance policies, and many safety codes covering multiple aspects of our lives.

But do we have water stored and a grab bag for emergencies?  Ah... maybe part of, sort of...  I think most of us are in this situation.  

The Christchurch earthquakes have been a massive wake up call for us all.  
Preparedness is actually quite straightforward to achieve.  The Civil Defence site gives sensible lists.  If you have friends or relatives living in Christchurch they will no doubt have additional items they are very firm in suggesting you add to your list, such as shovels and toilets seats!  And yes, it is that basic.  A wheelbarrow is now on my 'must buy' list, also a dog chain.  In disasters lost dogs on the loose are a real problem to house and tether.  I'm teaching my cats to wear and walk with a harness and leash.  I draw satisfaction from knowing that our well-stocked vegetable garden provides a good portion of our food and we have lots of preserves in the cupboard.  Beyond this I have a range of things I need to think through and get done.  When I've completed them I'll be confident that I've done what I can to prepare for looking after my own needs and that of my household in the event of a disaster.  That's a helpful, practical thing to know.  Beyond that I can't control events.  That's a good thing to be clear about too.  That's life.  Again, there are no guarantees.

We can not control the shaking of the earth, but we can prepare our homes and ourselves to be as safe and resourceful as possible.  Being properly prepared is reassuring.

To put earthquake risk into perspective I look at the relative chances of dying in an earthquake, a vehicle accident, or in an accident around the home: 
  • The chance of dying in an earthquake is relatively slim.  I don't have statistics for this, but given the number of residents living in Christchurch at the time of the earthquake and averaging that out over the nationwide population and back over time to include earlier earthquake fatalities, shocking and disastrous as these certainly are, such deaths are not that common.
  • Driving a car is way more dangerous, and yet we happily zip around in our cars, many of us daily.  The risk doesn't end with those travelling in vehicles, but is shared by everyone going about their business on or by any road.  In New Zealand more than one person a day is killed due to motor vehicle accidents - that's over 365 a year as you can read on the Ministry of Transport website.  We completely accept this, taking in these appalling statistics with our dinners as we sit in front of the tele in the evening.  Then we take the next forkful and go on to the next thing.  I'm not saying that this acceptance is at all right or proper; what I am saying is that this is what we do.  We really are very complacent about it.
  • Contrary to what you might think, our homes are the scene of many more accident fatalities, close on twice as many in fact.  You can read about this in this article which appeared in the ODT on 31st August 2010 30 Otago people die in home accidents
From this one can reasonably conclude that dying as a result of an earthquake is relatively unlikely.

The article Quaking in our boots: how prepared is Dunedin? was published in the ODT on 18th September 2010.  At the time the newspapers were so full of the drama of Christchurch's 4th September quake that I'm sure that most people didn't notice this article at all.  It's a comprehensive one and well worth a thorough read.  If you do look at it be sure to read all four pages, and bear in mind that Christchurch's 22nd February earthquake has cast some of the conclusions related in it into sharper perspective.  Those living in Otago in general and in Dunedin in particular would be well advised to take the lessons of Christchurch's situation to heart and to act on them.  This is not being alarmist, this is being practical.

Having said that, how likely is an earthquake this weekend?  
In the ODT article of 15th March 2011, No more earthquakes than usual: Dunedin geologist, Professor Richard Norris assures us that there are no more earthquakes occurring around the world than usual.  The reason that there might appear to be more is because in the last few years large earthquakes have struck heavily populated areas causing many fatalities.  He points out that similarly large earthquakes that occur in remote areas receive little attention and are quickly forgotten.  He assures us that fault lines in and around New Zealand are too shallow to cause tsunamis of the size recently experienced in Japan.  He further assures readers that he would happily go to Christchurch to stay for the weekend. I'll leave you to read the detail of the article for yourselves.

It's very clear to anyone who has taken the slightest interest in either of the Christchurch earthquakes that building choices, both of location and materials are likely to change considerably in the years ahead.  

It has been commented that buildings constructed of brick, stone and tiles have fared badly and homes built in the modern style on flat concrete pads laid directly onto the ground have suffered unprecedented breakage.  On the other hand those constructed of wood, roofed with corrugated iron, and built on more conventional foundations up off the ground have in general suffered significantly less damage.  

In terms of location, those with foundations on rock fared very much better than those on less solid ground.  Many low-lying areas of 're-claimed' land have been hard hit by liquefaction.  I am sure that our building code will be updated as a result of trends observed from both events.  

I have long been concerned about the recent trend of laying concrete foundation pads directly onto the ground.  A house built on the older style of foundations can be jacked up and re-levelled, even moved, but a house on a concrete pad that suffers inundation or fracture is wrecked from the bottom up and may have to be completely demolished.  Television news bulletins have shown this to have happened to a number of nearly new homes.  It seems crazy.  Just near where I live all the new houses in extensive property developments have these sorts of foundations.  They are in the neighbourhood not only of a major waterway but also sit on the edge of a flood plain.  In my view this is madness, plain and simple.  

It's worth noting that as the world's population increases more casualties from earthquakes can be expected simply by dint of increased population density. Furthermore, most of the world's population live in coastal areas or near major waterways.  

Stripping out natural protective barriers such as mangroves and sand dunes from our coastlines for the sake of having a nice view for a select few greatly increases the impact of flooding of any sort.  I read this point in discussion of the effect of the tsunami which impacted so disastrously along the shores of Thailand on Boxing Day of 2004.

New Zealand has been formed by the the shifting of the earth's tectonic plates, and continues to shift and change.  Mostly this change is so gradual that we are not aware of it.  Most of the time it seems safe and stable.  Our perspective on this is due to our relatively short lives.  In my earlier article New Zealand ~ land of earthquakes and volcanoes I look at this in greater detail.  Included in that article are videos which describe the natural history of the planet as a whole and how the continents have shifted and changed over the millennia. 

I grew up on the outskirts of Christchurch on a hill which overlooks Redcliffs and New Brighton.  From there New Brighton looks like a thin strip of sand and when I was little the horizon line of the ocean seemed to hover above it.  I did not understand that the water was not vertically above it in a perpetual wave, and worried what would happen if it fell down.  

I don't remember mentioning this concern to my parents and it seemed to be years before I realised I was mistaken.  Even so, vestiges of my early fear of inundation stayed with me, often causing nightmares.  Dispelling these sorts of fears can be difficult but can be helped by changing our point of view.  

Sometimes our way of looking at things can be influenced in unexpected ways:
Late in my teens I had a memorable dream which addressed this theme in a very different way.  It was so different that it permanently altered the way I regard this sort of thing, and it was for the better: 
I was standing alongside one of my brothers on the bluff at the foot of the hill where we lived.  It seemed to be in a time before any people lived there, a kind of prehistoric era as there were no buildings at all and no one else other than my brother beside me.  In what might be described as a time lapse of hundreds or thousands of years a series of events took place as I saw the land and the sea changing in a dream-like fashion: I saw a forest of trees begin to grow and then to populate the neighbouring valley as well as New Brighton across the water.  Then I saw water come in over the trees and the valley become a bay, and so on.  The land and water changed their relationship with each other numbers of times, with the changes flowing gently but surely into and through each other.  I understood completely that this change was natural and to be expected.  It wasn't threatening or cataclysmic, but more like a progression of seasons. 
This dream was immensely helpful and freeing.  I still have dreams about inundations, but in my waking life I don't have the same fear or resentment of them.  

And so it is with us: we have our own seasons and progressions, and like the Earth suffer bumps and bruises along the way.  Now, although I still fear disasters, it's not the same way or to the same extent.  One day I will die.  In the meantime I hope to make the most of my life here in this time and to live as fearlessly as I know how.  Life is an adventure, something like a camping trip perhaps.  There's a long time to rest afterwards when none of this will signify to me - in a physical sense anyway.  I think though, that if my soul continues on, that my love of the Earth itself, and all its glories, will be forever.  

But back to practical realities, back to the thump and bump of the physical world: what we can do is learn, understand, plan and prepare.  These simple steps can help us set aside undue worries about the future which will leave us more free to enjoy ourselves. 

I hope this article brings a measure of calm to those who have been anxious.  Let's all make the most of each other and this beautiful planet while we're on it.  I wish you all peace of mind and a satisfying life journey, whatever that means to you.

Note: On 22nd March 2011 the NZ Herald carried the story: It's better to be prepared than scared. In it the practical points I've made about the value of preparing for earthquakes and our chances of surviving them are closely reiterated by seismologist Caroline Holden of GNS.

Later Note: 'Moon Man Ken Ring in hiding after death threats' - ODT 24th April 2011.  The riot act (yes, it's true) has been read to Mr Ring forbidding him to make further predictions about earthquakes as he is not qualified to do so.  Good!

All my articles about the Christchurch earthquakes and aftermath can be found via the page linked to below, or at the upper right of this screen:

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