|SocialismToday Socialist Party magazine|
Natural or ‘unnatural’ disasters: hitting the poor hardest
ANTONIO GUTERRAS, head of the UN Refugee Agency, recently said that climate change is indirectly forcing large-scale resettlement of populations, which reached 37.4 million in 2007, a rise of three million. This shocking new statistic provides further evidence that the world’s poor are the biggest sufferers of disasters, unnatural or natural, whether in the USA after Hurricane Katrina, which was linked to global warming effects (Socialism Today No.95, October 2005), or in the ex-colonial countries devastated by the tsunami of 2004.
The death tolls after Katrina, the tsunami and, most recently, the earthquake in China were made worse by the neglect and indifference of governments to the plight of workers and the poor. The high death toll of 70,000 in China was partly due to the lack of seismic protection designed into buildings, despite strict existing regulations requiring that this be done. In contrast, the major quake in California in 1989, also in a densely populated area, resulted in only a handful of victims, largely because of seismic building design.
The widespread indignation in China as a result of the high death toll was fuelled particularly by the deaths of thousands of school students trapped in poorly constructed buildings. This was partly linked to the allegation made by Chen I-wan of the Committee of Natural Hazard Prediction for the China Geo-Physics Society, that the China Earthquake Administration (CEA) had received a warning of the quake and not acted on it. Chen said that he personally sent a prediction to the CEA of a scale six or seven quake in the Sichuan province that would occur between May 2008 and April 2009. Weight is added to Chen’s claim of official negligence if it is linked to a report in Nature magazine in 1999 that 30 false earthquake alarms in the previous three years had caused widespread economic disruption, and the Chinese authorities clamped down on ‘unofficial predictions’ as a result.
Leaving to one side for the moment the immediate claims and counter claims, this controversy raises the more general issue of whether prediction is a useful approach to addressing earthquake threats or whether the only way of mitigating suffering is to improve the infrastructure. This question is relevant in general terms to other disasters like Katrina and, of course, the tsunami, which was also caused by an earthquake.
Earthquake prediction has been subject of intense scientific debate and controversy for decades. In 1975, prediction was given a huge boost when, following extensive seismological survey and research work, China successfully predicted the Haicheng quake beforehand, and people stayed outdoors for several days despite the cold weather. When it happened it was recorded as a massive scale nine event, similar to the tsunami, and so thousands of lives were saved. The hope created by this success was not borne out though, when the following year 270,000 were killed in the Beijing area following an unpredicted earthquake. Further doubt was sown by an analysis published in the Journal of Applied Probability, in 2001, which found that prediction in China was at a very preliminary stage, barely above a pure chance level.
Perhaps because of the limitations of ground-based prediction methods, interest has been growing in using satellite monitoring. Distinctive cloud formations were found above an active fault in Iran 65-70 days before each of two large earthquakes occurred. At the same time, thermal images of the ground showed the temperature was higher along the fault. A theory was put forward by scientists from a university in Henan, China, that hot gases could have caused water in the clouds to evaporate.
Another idea was that ionisation may be involved, since it has been demonstrated that when rocks are squeezed, positively charged ions form in the air above them. (An ion is an electrically charged particle.) Sceptics point out, though, that ions usually help to form clouds, not disperse them. They also say that there are no physical models that could explain why this phenomenon would occur two months before a quake and then shut off and not occur again (New Scientist, 18 April 2008).
The fundamental problem with the science of prediction is that the underlying mechanics and thermodynamics of the behaviour of the earth’s crust are not sufficiently understood. For example, laboratory simulations have shown that the sliding of tectonic plates along fault lines seems to accelerate before the quake hits, but it has proved impossible to detect this acceleration in real-life situations. Consequently, prediction relies on statistical approaches that, inevitably, will have a significant degree of uncertainty.
An alternative method being pursued in California and Japan is to develop a system of early warning rather than prediction. This relies on an extensive network of monitors on the major fault lines, linked to a satellite system that gives an early warning. So far, the usefulness of this (very expensive) approach is limited, since it has been estimated that the ElarmS system developed at the University of California would give only a 15-second warning of a Richter scale five quake because seismic waves travel at six kilometres (3.7 miles) per second. The exact warning time would depend on the distance of populations from the epicentre – and even a short warning time could allow some evacuation to take place – but the current possibilities of this approach are clearly still limited. The controversy that arose after the Sichuan disaster must be viewed in this context, ie predicting the timing, location and size of earthquakes with useful accuracy is not possible with scientific knowledge at its present level.
Policies to save lives in earthquakes must be based not on prediction data but on designing and building the infrastructure to withstand the effects of the earth’s movement, as far as possible. Protection can be provided by using quake-resistant materials that can absorb greater quantities of energy than conventional materials before they collapse following sudden shaking, thus giving more time for evacuation, and building foundations can be designed to act as shock absorbers, attenuating the movement of the earth’s crust.
It is true that these approaches are expensive to implement in a poor country, but lower-tech measures can also be effective. For example, it is well known that unreinforced concrete and masonry is particularly susceptible to sudden collapse in an earthquake, which is what appears to have happened in Sichuan. Just simply using reinforced concrete more widely in this region, something there is no shortage of in China generally in the current building boom, would have made a big difference. For the poorest dwellings, even more basic methods could also have saved lives, such as placing strips of tear-proof fabric between the layers of adobe structures, essentially tying the building together, giving crucial extra time before collapse. Also, since they can withstand shaking more effectively, building wooden structures rather than unreinforced concrete ones, would have been preferable.
The Chinese regime is culpable not because it ignored imprecise and unreliable predictions of possible disaster, but because it failed to ensure that even simple and relatively cheap measures were implemented that could have saved tens of thousands of lives.