Earthquakes this year have cast doubt on our preparedness for natural disaster and highlight the exposures posed by growing concentrations of population. Maria Kielmas gives her views.
When pictures of the death and destruction following the Turkey and Taiwan earthquakes were beamed to the United States, the average viewer might have been forgiven for thinking that such a disaster occurring in the US would not result in the same chaos. Though often battered by earthquakes, floods and windstorms, the US at least has a functioning system of building code enforcement, emergency response, insurance industry liquidity and government accountability, all of which combines to rescue, rehouse and rebuild after disasters, thus avoiding the kind of ongoing misery which face half a million homeless people in Turkey throughout the coming winter.
Not quite, said Thomas Briggs, professor of engineering at Cornell University, when testifying before the subcommittee on basic research of the House of Representatives Committee on Science on 20 October 1999. “We should not think we are safe because our code adoption and compliance are better than Turkey's” he warned.
Upwards of 80% of building stock in earthquake-vulnerable areas was designed before certain modern design principles learned from damage observed in past earthquakes were incorporated into building codes. These buildings could behave in a similar way to those in Turkey.
Throughout the world, economic development, population growth and migration from the countryside during the last three decades of the twentieth century have resulted in the creation of megacities with an agglomeration of extreme wealth and extreme poverty.
A major earthquake, flood or typhoon striking one of these conurbations could have massive economic, social and political consequences. Where rich countries are concerned, the potential economic losses are often quoted. Munich Reinsurance estimated that an really major earthquake hitting the Tokyo Bay area, where the population is about 35 million, could generate economic losses of between $2.1 to S$3.3 trillion, though the insured losses under the Japanese system would be a relatively smaller $50 billion. A major windstorm hitting Florida could cause $50 billion in insurance losses, while a major flood in the most populated parts of western Europe could cause insurance losses of $30 billion.
But urban growth has been most marked in developing countries, particularly in Asia and Latin America. The world's population has almost doubled since the 1950s. According to UN figures, Asian cities account for about 46% of the world's urban population, though only about one-third of the region's inhabitants live in cities. Nearly 80% of Latin America's population lives in cities, while Africa is the world's most rapidly urbanising region. By 2015, the UN predicts, Beijing will have a population of 15.5 million, Bombay 26.2 million, Calcutta 17 million, Lagos 24 million, New York 17 million, and Tokyo 29 million. Such a concentration of people and property means one catastrophic event can wipe out a significant proportion of a country's GDP, usually in inverse proportion to its size and wealth. The August earthquake in Turkey's industrial heartland cost about 7% of that country's $190 billion GDP; the 1994 Northridge earthquake in the US cost $30 billion in economic losses, but just 0.38% of that country's GDP. The 1972 earthquake which hit Managua wiped out 40% of Nicargua's then $850 million GDP.
International consciousness about the consequences of these disasters has changed. Hurricane Mitch caused $5 billion of damage in Central American countries which were trying to recover politically and economically from the civil wars which ravaged the region in the 1980s. Donor countries and international institutions have pledged $5.3 billion in reconstruction and development aid, enabling Nicaragua, Honduras, Guatemala, El Salvador to continue on the reform path. One reason given by analysts for this generosity was that Mitch was not a natural but a man-made event caused, in part, by the developed world's damage to the environment and global warming.
The view that natural catastrophes may be not so much a force of nature but an act of man's criminal negligence was reinforced by popular disgust at the shoddy buildings whose collapse killed so many in the Turkey and Taiwan earthquakes. Calls abound for the strict enforcement by non-corrupt government of the best international standards.
There is little public debate about the shortcomings of natural hazard assessment in the immediate aftermath of an earthquake when rival engineering consultants compete for attention from a media circus clamouring that “something must be done.”
During his testimony on US earthquake preparedness to the house subcommittee, Professor Briggs asked, “How effective are our evaluation techniques? How effective are the earth sciences people in providing useful site-specific data? How imaginative is the engineering community in devising effective and affordable risk reduction? How effective are our policy experts in developing politically acceptable policies and programmes?”
The answer is that although individual experts may be extremely talented, inter-disciplinary communication is poor and there is little enthusiasm from essentially publicly funded institutions to admit openly that for natural catastrophes, there is no such thing as an absolute assurance.
Earthquake engineers are sometime prone to hubris, saying that it is possible to design buildings to withstand earthquake damage entirely and that there is a sophisticated understanding today of soil response. The real truth is that earthquake engineering is still a trial and error method built upon a probabilistic assumption and where the earthquake is the test. Progress has been primitive in comparison with the development of information technology tools available for modelling.
The oldest rocks on the planet are 4.7 billion years old and this is usually taken to be the age of the earth. Reliable strong motion data, the necessary input to earthquake resistant design, has existed for about 50 years. In some countries, there are ancient historical accounts of earthquakes over several thousands of years, but the interpretation of these and older instrumental records this century needs a sharp instinct for the history of the time, as well as regular revision of one's own assumptions.
Californian seismologists have tried to make up for the disparity between human and geological time scales by developing paleoseismology, the identification of earth movement in the recent geological past. The principle is to dig trenches around major fault zones and identify buried phenomena that indicate the fault's movement for say, 10,000 years, and so beef up the statistical database. But the accuracy of results is mixed; a subsequent earthquake can obliterate the effect, and the method cannot easily be applied in different geological environments, such as Japan, Indonesia and the Indian subcontinent. But it does provide an indication of extreme events, scenarios which human beings, even risk managers, often have difficulty imagining.
The study of the immediate geological past not only gives indication of past earthquakes but also past climate. Carbon isotope dating has demonstrated surface temperature fluctuations tens of thousands of years ago of several degrees Celsius over a decade. This was long before the invention of the internal combustion engine and fossil fuel emissions into the atmosphere. A public debate about the real drivers of climate, such as the interaction between oceans and atmosphere, the relative distribution of land mass to the sea, fluctuations in the earth's axis, and above all solar activity, has been effectively diverted by environmentalist pressure groups pursuing an anti fossil fuel agenda.
No scientist doubts that burning of fossil fuels increases existing naturally generated greenhouse gases in the atmosphere. But one major volcanic eruption, such as Mount Pinatubo in 1991, really did change the climate when the Middle East experienced its worst winter in living memory. Meanwhile, perceived rises in sea level in some areas could often be man-made directly. The construction of harbours, beaches and tourist facilities in coastal areas alters current and, effectively, sea level patterns.
The pressing need in cities such as Sao Paulo, Bogota or Bangkok for reliable public utilities, waste disposal, transportation and energy supply seems to conflict with calls in the northern hemisphere to scale down development ambitions to renewable and sustainable methods. But the exploitation of natural resources and provision of food, energy and services to megacities, need not conflict with preservation of the environment.
The answer is a multi-disciplinary approach to disaster mitigation where scientists, politicians, bureaucrats, entrepreneurs, community leaders and the like sit down and hammer out a solution. One such attempt is the Earthquakes and Megacities Initiative (EMI). This is an attempt to disseminate information and experience on earthquake hazard assessment and mitigation in urban environments, and develop the capacity to deal with it. It is the brainchild of Fouad Benimerad, vice president of Menlo Park, CA-based Risk Management Solutions (RMS) Inc., and Friedmann Wenzel, professor at the Geophysical Institute, University of Karlsruhe, Germany.
The first step is to get the scientists talking together, says Dr Benimerad. There is very little interdisciplinary communication between scientists, despite an ever-growing list of conferences. Then bring the scientists together with policymakers to consider the best ways approaching earthquake hazard. City governments are more concerned with the immediate questions of poverty, violence and pollution than the danger of an earthquake sine time in the next 30 years. One of EMI's programmes is to “twin” cities that can exchange knowledge and experience in disaster mitigation. The pairs are Los Angeles and Mexico City, Bogota and Managua, Athens and Istanbul, Naples and Cairo, and a threesome, Shanghai, Kobe and Metro Manila.
EMI is to hold a workshop in Istanbul next year. The Turkish government for its part has already responded to public anger about the earthquake by switching the responsibility for building code enforcement from the governors of provinces to the mayors of cities. In addition, design engineers and contractors will be legally obliged to hold liability insurance if they wish to practice. A new industry, not government, watchdog is to be created to oversee the construction sector. For Mustafa Erdik, professor of civil engineering at Bogazici University in Istanbul and a scientific adviser to EMI, this is all good news. Prior to the August earthquake, Turkish contractors never bothered to ask for advice from local earthquake engineers. Today there is a flood of supplicants.
EMI is the latest of a number of such initiatives over the years. Its problem is that at the moment it has no members from the commercial world, such as the construction industry. “You need a mixture of scientific, technical and commercial people. Scientists are reluctant to see commercial problems,” says Herbert Tiedeman, retired engineering consultant for the Swiss Reinsurance.
That cities prone to natural catastrophes exchange information and expertise on a multi-disciplinary level is indisputable. The fundamental issue is how to create a culture of regulation enforcement in countries, be they Peru, Turkey or Indonesia, where the state is pervasive but state institutions, such as the judiciary and legislature, are endemically weak and/or corrupt.
The provision of vital services can become a political football between local and central authorities. Bureaucrats in different departments rarely talk to each other and politicians often use the position of city mayor as a stepping stone to the presidency. For such a programme to be effective its participants must contact not just those in power, but those who in ten years time might just have an outside chance of being in power. In other words, the strategy of the intelligent multinational investor.
Engineers insist that today's technology can solve 98% of the everyday problems with natural disaster mitigation, but the more complicated the problem, the more expensive the solution. Professor Briggs called for a reassessment of active fault zones in the US especially with respect to critical facilities such a hospitals, schools, lifelines etc. These faults are not always visible on the surface. The Northridge earthquake was caused by just such an effect. A tight-grid, three dimensional seismic survey which penetrates about seven kilometres underground could identify existing faults not visible on the surface, though obviously not new ones which will be created in the future. But such a survey today could cost about $100,000 per square kilometre, and then on only a half kilometre grid. It would be very difficult to make sense of the faults identified unless the entire state of California, and possibly northern Mexico, were to be surveyed. Who would fund this?
Dr Tiedeman believes that the development of a sense of risk-awareness in an urban community need not cost a lot of money. A ready hosepipe, bucket of water and bicycle pump could have put out a lot of the post-earthquake fires in Kobe's old town. This is just what householders in Britain and Germany did during Second World War bombing. Even retrofitting schools and public buildings does not have to be expensive.
But for a family in a poorer environment to maintain its dwelling properly, it first needs title to it. Title to land and property is one of the most explosive issues in developing countries where central government fears losing control over increasingly vocal local communities and indigenous groups.
Governments have shown that they can learn from past mistakes, as shown after the 12 November Duzce earthquake in Turkey. Rescue teams, including 4,000 troops, were sent in immediately to the disaster site, even though the damage caused by this earthquake was a fraction of that resulting from the Izmit earthquake in August.
Scientists and reinsurers can co-operate quite efficiently to assess hazards in particular environments and, thus, monitor and control aggregate exposure. But this can only be done in areas above a minimum wealth threshold, which often frequently does not apply to the areas of greatest disaster.
Turkey's current economic model is one of industrialisation based on cheap labour, a model followed throughout most of the developing world and its megacities. In this context, there is a cap on the rents, housing costs and, therefore, quality of the housing available. Can insurers and reinsurers play a role in ensuring the quality of low-cost housing by linking it, say, to a micro-insurance programme? Dr Tiedeman says no. He believes that this is entirely a political issue and not a job for reinsurers.
There is no universal answer to natural catastrophe mitigation any more than there is a uniform predictive formula for disaster occurrence. Every city and society needs a bespoke solution which brings together politics, economics, culture, geology and meteorology. All can benefit from an exchange of experience, and a little bit of humility in the face of forces which humans will never control.
Maria Kielmas is a freelance writer. By background she is a geologist and seismologist and has worked in the reinsurance and energy industries.