Copies of most of the presentations made at the EERI Annual Meeting and National Earthquake Conference (April 10-13, 2012, Memphis, TN) are now posted openly on the Internet. Many are limited to the presentation slides but of some interest nevertheless because of recent, damaging earthquakes in Haiti, Chile, New Zealand and Japan. For example, one succinct presentation, Lessons Learned from the Performance of Highway Bridges in Recent Earthquakes – by Ian Buckle, skillfully outlines bridge performance considerations in three of these recent, large earthquakes and tsunami(s).
Archive for May, 2012
Harvard Physics and Applied Physics Professor Eric Mazur’s video “Confessions of a Converted Lecturer“ provides personal, pedagogical experience centered on an established educational technique now referred to as ‘peer instruction’ – a teaching method in which a question is posed to the class and then students are asked to explain their answers to one another. Professor Mazur’s observation “I thought I was a good teacher until I discovered my students were just memorizing information rather than learning to understand the material. Who was to blame?…” leads to surprisingly compelling viewing for those teaching (or learning) higher level science and engineering classes. Techniques probably play well with growing online university courses such as at Coursera and EdX.
Some startling statistics regarding natural disasters are displayed on a World Bank, IEG natural disasters website —
But what does 3,852 natural disasters, 780,000 natural disaster fatalities, costs exceeding $960 billion in the last ten years mean for earthquake engineering? Are things becoming worse for earthquake disasters? When examining natural disasters since at least Voltaire’s review of the 1755 Lisbon earthquake, two scales are “…generally used to weigh the misfortune of men and estimate their sorrows…” (Candide, 1759) : human mortality and societal costs.
In terms of mortalities, clearly, in the face of an equal number and intensity of shocks as poorer nations, richer nations suffer less deaths from natural disasters. As demonstrated in “The Death Toll From Natural Disasters: The Role of Income, Geography, and Institutions” (September, 2003) by Matthew E. Kahn -when using 1990 as the base economic year and longitudinal disaster information derived from the Centre for Research on the Epidemiology of Disasters (CRED) – if a nation with a population of 100 million experienced a GDP per-capita increase from $2,000 to $14,000, this nation would suffer 700 fewer natural disaster deaths per year.
— Predicted Annual Death From Natural Disasters –(1990 base year)
|GDP Per-Capita||Expected Deaths||Probability Death equals zero|
Why would this be so? Convention suggests that as societies develop economically, they can afford the human skills, training, oversight, and physical infrastructure needed to protect against, and respond to, natural disasters. In other words, disaster-mitigating and emergency response measures that reduce fatalities are undertaken by individuals and governments as wealth increases. But, as could also be expected, are reductions in societal losses similarly associated with increased disaster mitigation and emergency response expenditures?
Natural disasters around the world in 2011 caused a record $380 billion in economic losses, more than twice the total for 2010 and about $115 billion more than in the previous record year of 2005 (according to a report from Munich Re in Germany). Nearly two-thirds of 2011′s losses are attributable to two earthquakes in highly-developed countries notorious for their disaster mitigation measures and earthquake preparedness: the Tohoku earthquake (M=9.0) and tsunami that devastated northeastern Japan in March, and February’s smaller but very destructive earthquake (M=6.3) in Christchurch, New Zealand. [Scientific American, January 12, 2010]
In fact, the Economist magazine reports that four of the five costliest natural disasters since 1980 are earthquakes in developed regions of the world – although the real costs from poorer countries may be underrepresented here since total disaster damage costs are often estimated using an economic multiplier of known insured losses while very expensive and volatile insurance premiums combined with the insurance industry’s limited capacity to absorb extreme risks, prohibit many poorer countries from obtaining any insured losses.
|1. Earthquake and tsunami, Japan (2011) –Cost: $235 billion (by the World Bank)|
|2. Kobe earthquake, Japan (1995) — Cost: $100 billion (by the World Bank)|
|3. Hurricane Katrina, U.S. (2005) — Cost: $81 billion total damage cost (by NOAA)|
|4. Northridge earthquake, California, U.S. (1994) — Cost: $42 billion (by NOAA)|
|5. Sichuan earthquake, China (2008) — Cost: $29 billion (by the World Bank)|
Why are these earthquake damage costs so high? A research report commissioned by the re-insurance industry, A Trend Analysis of Normalized Insured Damage from Natural Disasters (Climatic Change, May 4, 2011) by economists Fabian Barthel and Eric Neumayer concluded that “the accumulation of wealth in disaster-prone areas is and will always remain by far the most important driver of future economic disaster damage.” In this study, ‘normalization’ adjusts nominal economic loss from past disasters upwards by multiplying past damage with a factor for inflation, for population growth and for growth in wealth per capita, thus in effect estimating the damage a past hazard event would have caused had it hit the same, but now wealthier, area today.
Relentless commercial and population pressures contribute to the accumulation of wealth and the concentration of people and economic activity in disaster-prone places – on tropical coasts or river deltas, near forests and along known earthquake faults. The Economist magazine reported a 2007 study led by the OECD which “reckoned that by 2070, seven of the ten greatest urban concentrations of economic assets (buildings, infrastructure and the like) that are exposed to coastal flooding will be in the developing world; none was in 2005. In that time, assets exposed to such flooding will rise from 5% of world GDP to 9%. A World Bank study estimated that between 2000 and 2050 the city populations exposed to tropical cyclones or earthquakes will more than double, rising from 11% to 16% of the world’s population.”
This increased exposure to natural disasters may partly derive from a ‘moral hazard’ implicit in both natural disaster risk insurance and an increased reliance on existing disaster mitigating technology regardless of location. But as the Tohoku and Christchurch earthquakes revealed in 2011, naturally occurring incidents, especially the improbable ones, within even the wealthiest countries can still result in many fatalities and very large physical damage losses that multiply through distributed economies. Neither our hazard risk assessments nor our mitigating technology are as advanced as we now need it appears. When populations and productive infrastructure continue to cluster in high risk locations, fatalities may continue to decline as per-capita GDP rises, but societal costs may continue to rise. In 2010, a senior World Bank administrator observed that “If we are ready to invest sizable funds to establish mechanisms to withstand financial crises, we need to do the same with the escalating hazards of nature.” However, a July, 2009 World Bank working paper “The Growth Aftermath Of Natural Disasters” by Thomas Fomby, Yuki Ikeda and Norman Loayza observed that “while the impact of some natural disasters can be beneficial [the authors refer to economic reconstruction mostly] when they are of moderate intensity, severe disasters never have positive effects. … Not all natural disasters are alike in terms of the growth response they induce, and, perhaps surprisingly, some can entail benefits regarding economic growth. Earthquakes have a negative effect on agricultural growth but a positive one on non-agricultural growth.” In earthquake sciences, perhaps some things are never completely worse.