OPINION: Professor Mike Ardagh has been following the recent questioning of emergency service personnel involved in the Christchurch earthquake response. He says the February 2011 quake needs to be kept in perspective.
On the television, they said some external consultants were critical of Civil Defence. I saw a policeman being questioned in court like a criminal, and a fireman welling up when he tried to explain why he did what he did.
I read in the paper that the emergency services response wasn't textbook.
"Earthquake emergency response seriously faulty - something must be done," said the editorial.
It seems the whole thing was a bit of a balls-up.
In 2005, two researchers from California, Marizen Ramirez and Corinne Peek-Asa, published a paper in a journal called Epidemiologic Reviews identifying the features of earthquakes associated with a higher incidence of injuries and death. Not surprisingly, they found that these three things were important: the intensity of the earthquake, the time of the day and the quality of the buildings.
The intensity of the earthquake isn't the same as the magnitude. The magnitude is how much energy is released at the site of the earthquake. The intensity is more about how much the earth moves.
Peak ground accelerations are one way of describing intensity. In California, where many earthquakes have occurred, they found that peak ground accelerations were highly predictive of fatal and non-fatal injury.
On February 22, 2011, peak ground accelerations in Christchurch were measured as high as 2.2g (1g equals 9.81m/s2 - metres per second squared). These, I understand, are among the highest ever recorded and are the highest vertical peak ground accelerations (the earth moving up and down) ever.
The second association with injury is the time of the day the earthquake hits. If you are at home in bed, as was the case for most Canterbury people in the September 4, 2010, earthquake, you are more likely to be OK. If you are in the city, you are more likely to be injured or killed. Lunchtime on a weekday is a bad time to have a quake.
So Christchurch had a high-intensity earthquake (peak ground accelerations up to 2.2g) at the worst possible time (the middle of a working day), 185 people were killed and nearly 7000 were injured.
In contrast, Kobe, Japan, had an earthquake in January 1995 with peak ground accelerations no higher than 0.82g, at 5.46am on a Tuesday. The number killed was 5488 and more than 36,000 were injured. Of course, a greater population was exposed to the quake - about 1.5 million.
However, while the population was only a little over three times that of Christchurch, the death rate was nearly 30 times higher, and this was even though the earthquake was of lower intensity and occurred at a better time of the day.
In Bam, Iran, in December 2003, a 0.98g quake struck just before 5.30am and killed 26,000 people out of a total urban population of 97,000.
In Haiti in January 2010, a 1.24g quake struck just before 5pm and killed 230,000.
Our buildings are stronger than those in Bam and Haiti, but even in Los Angeles in January 1994, 72 people were killed and about 5000 were injured, even though the quake struck at 4.30am and the peak ground accelerations were no higher than 1.78g.
Christchurch had a massive earthquake at a bad time and despite that the numbers killed and injured were relatively low.
There are many reasons for this, but I think, as well as our engineers and builders, we should thank our fire, police, ambulance, Urban Search and Rescue, Civil Defence and many others.
Of course, we need to examine what happened, how we responded, and how we can improve, but we need to get things in perspective.
The response of the health system in Christchurch has been consistently praised, including in the review of the Civil Defence response, in some independent research from researchers at the University of Canterbury (The Press, Nov 3, 2012), in an editorial from the president of the Royal College of Surgeons of Edinburgh published in its journal (unbeknown to us, he was in Christchurch Hospital Emergency Department with his injured wife during the influx of quake casualties), and in a paper describing the initial response in the international journal Lancet, albeit with a potential bias, since we wrote it ourselves.
However, I am sure if we employed consultants to do a review or were questioned by lawyers, they could pick holes in the response.
Indeed, we can pick holes in it ourselves - we have and we are plugging those holes, as we should, so that we do it even better next time, in the unlikely event we need to.
Like all of us who were here, I remember February 22, 2011. After the quake, the injured, the desperately sad and the scared flooded into the hospital. They came on foot, on the backs of trucks, in strangers' arms, strapped to cars, carried on makeshift stretchers.
They had to. The roads were a mess. The lights went out, the phones didn't work, ceiling panels fell on people, bits of the hospital flooded, the elevators wouldn't take the injured upstairs to the operating theatre, the CT scanner or the Intensive Care Unit and the place kept shaking.
But most of all, I remember good people doing excellent things under very, very unusual circumstances.
However, I wasn't out there among the dust and the rubble, the devastation and the danger, the heat and then the cold southerly, and the hundreds of people - many wanting to help and many needing it.
I wasn't trying to make sense of the unfathomable, control the overwhelming, or build a plan on a foundation of uncertainty, rumour and conjecture.
What a hell of a job and, under the circumstances, they did a hell of a job. Let's not forget that.
Mike Ardagh is professor of emergency medicine at the University of Otago's Christchurch campus.
- © Fairfax NZ News
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