SEOUL, Korea, October 28, 2010 — Take a chilling statistic: Ninety percent of all earthquake fatalities worldwide since 1960, over 1,100,000 people, have been Asians. Even at this writing, all major news networks are reporting a magnitude 7.5 quake off Padang in Sumatra, Indonesia. Ironically, Professor Tso-Chien Pan, Director of the Institute of Catastrophe Risk Management, Nanyang Technological University, Singapore, predicted a major quake in this region the night before at a World Bank GDLN regional conference from Seoul titled, “It’s Not too Late: Preparing for Asia’s Next Big Earthquake”.
Experts know where, but not yet when, the next killer quake in Asia might strike. Some Asian megacities lying close to tectonic fault lines are showing increasing seismic activity—Manila, Jakarta, Penang, Tokyo-Kobe. And yet, few countries in the region, with the exception of Japan and New Zealand, have a proper earthquake mitigation program. Asia’s historic vulnerability to killer quakes is made more acute today by the fact that 11 of the world’s top 15 megacities with populations over 15 million are now in Asia. These cities are huge, rapidly developing urban conglomerates, containing some of the world’s tallest buildings—alongside mega slums and informal settlements, most of them on land unsafe for human habitation.
This is why a comparatively moderate 6.3 magnitude quake near Padang in 2007 resulted in 66 fatalities, 500 casualties, collapse of nearly 15,000 buildings and lesser damage to 44,000 structures. As a result, over 135,000 people were displaced. “These are very high numbers for such a moderate earthquake in an area with a long history of much larger earthquakes,” says Peter Yanev, arguably the world’s leading earthquake expert and engineer, author and consultant for one of the developing world’s most successful earthquake mitigation programs in Istanbul, (ISMEP), at this point mostly funded by the World Bank.
So what would be the earthquake scenario for a big Asian metro today? “The severity of earthquake impact in a megacity of millions, with poor housing or modern skyscrapers built without implementation of proper building codes could be devastating. Depending on the location, an 8.5 magnitude quake could easily leave between a quarter to a million dead and completely collapse between 1 and 5 per cent of buildings, damaging more than 50 per cent, near an epicentre,” says Yanev.
“And think about this: today a US$50 million building may contain destroyed equipment worth US$2 billion. The recent earthquake in Chile, for example, left the new airport relatively undamaged, but with much of the equipment damaged or destroyed, the airport was unusable when it was needed most,” says Yanev, “the same is true of hospitals”. The World Bank currently has a billion dollar reconstruction program in EAP, and experts like Peter argue this could have been considerably reduced if some simple measures had been enforced. So what can nations do to build resilience and mitigate the impact of earthquakes?
Peter Yanev's checklist for earthquake impact mitigation:
Start with a risk scenario of losses to your city. So far, I’m only aware that Manila has one. This creates a realistic picture of the threat and is important to mobilise public and political support. Following two destructive quakes in 1999 near Istanbul, the Turkish Government, supported by the World Bank, did a systematic risk audit beginning with schools. “When large numbers of school children die as happened in Wenchuan, the outcome affects not just their immediate families but the extended community and a nation’s future. And because schools have large rooms with fewer internal walls, they are structurally weaker. Experience shows a program that demonstrates the value of saving lives gathers support.
One of the key lessons of the 2008 Wenchuan earthquake in China (70,000 dead, US$122 billion in real estate losses) is the importance of earthquake mapping and zoning for adequate building codes. When I visited L’Aquila in Italy, after the earthquake, I found that although the city was in an area with well known high seismic risk, it had building specifications for a much lower risk scenario. Again, in Istanbul, we found the military buildings where the codes were enforced were mostly undamaged while hundreds of other nearby were destroyed.
Then do a cost-benefit analysis for quake-proofing buildings. In Istanbul, the rule was if the cost of reinforcing a building was more than 40 per cent of constructing a new one, then it’s better to tear it down and build a bigger, stronger one. We know enough about earthquake engineering—I have visited over a hundred quakes and/or directed their investigations since 1970—to do it relatively cheaply and effectively. For instance, in Istanbul, five schools could be reinforced for the price of building one.
The next step is the only one that matters: where should the money be spent? Evaluate the target buildings. In Turkey we prioritized buildings nearest to the fault, in Manila it could be buildings on poor soils. Develop performance criteria: Do we want a school that will fully withstand quake impacts (expensive) or schools that may have masonry damaged (less expensive). Reinforced concrete walls provide protection but so do much cheaper confined masonry walls, as was demonstrated by many 1930s houses that withstood the Chile quake. Newer is not always better.
To the question that poor countries cannot afford the decades of investment it will take to build resilience in existing infrastructure, Yanev does the math: "A building frame typically accounts for 15% of the cost of the building and you would add one to three per cent to reinforce it against earthquakes. About 85% of the building cost is what’s inside the building."
"Sharing earthquake mitigation expertise and helping take the policy dialogue forward with governments and partners is an important part of our work in the region," says Abhas Jha, who manages the World Bank’s East Asia Pacific Disaster Risk Management program. "Partnerships like the one with the Institute of Catastrophe Risk Management and others are important in helping to evolve tools to help assess the risks of earthquakes and measures that can be taken to reduce them. You don’t need big investments to save a large number of lives, you need community awareness and effective action plans for building safer cities."