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EarthquakesPost-earthquake losses: Devastating and costly

Published 28 August 2017

Since 1900, 2.3 million people have died in 2,233 earthquakes, yet it is important to understand that 93 percent of the fatalities that occurred as a result of violent earthquakes happened in only 1 percent of key earthquakes. In other words, the worst devastation tends to happen in only a very few quakes and generally as a result of dire secondary effects. A new study recommends we shift our focus to learn from and prepare against the range of disasters that typically follow — and for which we are often unprepared.

Earthquakes: Nature’s most unpredictable and one of her most devastating natural disasters. When high intensity earthquakes strike they can cause thousands of deaths and billions of dollars in damaged property. For decades, experts have studied major earthquakes; most have focused on fatalities and destruction in terms of the primary effects, the shaking unleashed.

A new study takes a different approach to generate a more complete picture.

The study, titled, “Losses Associated with Secondary Effects in Earthquakes,” published in Frontiers in Built Environment, looks at the devastation resulting from secondary disasters, such as tsunamis, liquefaction of sediments, fires, landslides, and flooding that occurred during 100 key earthquakes that occurred from 1900 to the present. And unlike previous studies, Daniell et al put a dollar value to the devastation from these secondary causes.

Frontiers notes that Since 1900, 2.3 million people have died in 2,233 earthquakes, yet it is important to understand that 93 percent of the fatalities that occurred as a result of violent earthquakes happened in only 1 percent of key earthquakes. In other words, the worst devastation tends to happen in only a very few quakes and generally as a result of dire secondary effects. Indeed, fully 40 percent of economic losses and deaths result from secondary effects rather than the shaking itself. Several key earthquakes have changed our knowledge of secondary effects and serve as models to understand and heed in planning communities, homes and buildings, highways, and infrastructure such as nuclear power plants.

In 2004 the Indian Ocean earthquake unleashed tsunamis that killed a total of 227,300 people in Indonesia, Sri Lanka, India, and Thailand, plus more than $10 billion in damages. In 2011, the Tohoku earthquake created a series of huge tsunami waves, which damaged coastal communities killing more than 17,900 people, forcing more than 50,000 households to relocate, and caused the Fukushima nuclear power plant failure, a nuclear disaster second only to Chernobyl in Russia in 1986, but which spread radiation across the Pacific Ocean. Studying the Indian Ocean and Tohoku earthquakes gives us information to create maximum tsunami height models for these high-risk areas to better predict how populations, property, and gross domestic product might be impacted in the future by similar events.