Earthquake Survival: Surviving an Earthquake

Earthquakes I know something about - I am both a trained geologist and a New Zealander. I understand earthquakes and I know how to survive them - surprisingly it has little to do with having an earthquake survival kit. Disclaimer: I have only survived minor earthquakes to date. Maybe if I don't answer your comment the "big one" hit already and I was wrong!Mind you the common sense approach seems to have worked well in the recent Christchurch earthquake.

Earthquake Survival Kits

Lets start with these because for most people this is where they start with earthquake preparedness - they start with an earthquake survival kit. They get together some bottled water, some canned food and a radio with batteries, a first aid kit. That's nice and can be useful - though the food isn't a big deal if you live in a Western country - you will take about a month to starve to death - whatever you think of emergency services they should have got to you by then. So an earthquake survival kit is a nice to have - but there are some more important things to consider first. On the other hand having having a few litres of water in sealed containers makes a lot of sense.Real earthquake preparedness is little bit more difficult and is all about the building you are in at the time.

Most people think of earthquakes and think of the rim of fire: the circum-Pacific belt of active faults and volcanoes which includes: New Zealand, China, Japan, Alaska, California and Chile all of which get frequent and nasty earthquakes. Places like Europe and Australia don't.

WRONG. Earthquakes can occur anywhere - they are far more common in the countries I listed but L'Aquila Italy had a devastating 6.7 magnitude earthquake in 2009 and the Western Australian town of Meckering was destroyed in 1968 by a 6.9 magnitude earthquake.

But right to - countries that either don't have earthquakes very often, or don't have a modern earthquake building code, have a much higher casualty rate. Check out video of the damage done in New Zealand's Gisborne 2008 earthquake. It looks dreadful - how many died - one - an elderly lady who had a heart attack. So much damage so few deaths - how did that happen?

Two issues: how we measure earthquakes and building standards.

When the news media quote a "6.9 magnitude earthquake" - they using the Richter scale. This measures the force of the earthquake at its epicentre. Not on the surface of the earth - but at the point that the earthquake occurs - often many kilometres below the surface. The original strength of the earthquake is part of the answer to how much damage an earthquake will cause - but its not the only factor, for deathrates its not even the most important factor.A 7.1 earthquake in New Zealand killed one person, a 6.9 in China killed thousands - different ground conditions, and critically, different building standards

This is the single most important factor for surviving a earthquake: the building you are in. You statistically most likely to be in a building the authorities will tell you that if you are in a building stay in it. I say, maybe...

In a building which complies to stringent earthquake standards the building that will save you. It will do exactly what those Gisborne shops did - extraneous material such as shelving, and ceiling tiles will collapse and make a big mess. But the roof will stay up for a quite a long time. If the entire building does collapse then it will create big gaps in the building - gaps which will protect you and probably trap you, not kill you.

The tragedy of the 2008 Sichuan China earthquake is not that the earthquake but the abysmal building standards. The same happened at L'Aquila - the 500 hundred-year-old classic buildings survived - as they have other earthquakes the 1960 apartments did not.

The majority of New Zealand's property is wooden, particularly in Wellington. That's because the town was destroyed twice by earthquakes in the 1850's. The third time they didn't build in brick - and the 1941 earthquake destroyed a huge number of chimneys but few major buildings.

Run Outside an Unsafe Building

Decide whether the building you are in is safe. I used to work for a geotechnical engineer in Wellington, our office was one of the buildings that at the time was considered completely unsafe, it was unreinforced brick warehouse on reclaimed land, we were on the first floor in an open plan office.

The earthquake plan was simple - sprint for the stairs and throw yourself down them, seriously. The stairwell is the most likely structure to survive. We had one slight shake - I was wondering whether it was a quake my boss, somewhat overweight and not particularly fast-moving normally - was 1/2 way to the stairs - if in doubt in a bad building move. As the shaking increases you wont be able to stand nevermind run.

I would use this principal for any building in countries that "don't have" earthquakes such as Ausralia. Also countries like Mexico and China who demonstrably don't have building standards.

Stay Inside a Safe Building

By the way this is the official advice from authorities. The main danager is flying debris - get under a desk and hold onto the legs - the desk will walk - you need to go with it. Or in a doorway sit down and brace yourself - protect your head. Unless there is fire - stay there. The earthquake may be the first of several - a quake can last 1 minute or come back within two or three minutes, or many hours later.

If you are driving - try to avoid being on over-passes, elevated roads or a tunnel, it you are coming up to one stop immediately. Stay in the car to protect yourself. If live wires fall across the car - stay in the car - the tyres are protecting you from shock.