Dissipated force and resistant structures helped

INFRASTRUCTURE: Luck and preparation have combined to keep casualties relatively low in Chile, writes Rory Carroll

INFRASTRUCTURE:Luck and preparation have combined to keep casualties relatively low in Chile, writes Rory Carroll

CHILE’S EARTHQUAKE was many times more powerful than the one that devastated Haiti in January but caused a fraction of the casualties, thanks to geological luck and the country’s preparation for such a disaster.

Saturday’s 8.8-magnitude quake was a “megathrust” which unleashed about 50 gigatons of energy, but it was centred offshore and about 21 miles underground, dissipating its force by the time it reached towns and cities. In contrast, the seven-magnitude quake that struck Port-au-Prince on January 12th was much shallower – about eight miles deep – and right on the edge of a city where three million people lived.

Eight Haitian towns and cities suffered “violent” to “extreme” shaking, whereas Chilean urban areas did not suffer more than “severe” shaking: still horrible, but in relative terms not as bad.

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The other reason Chile was counting its dead in the hundreds rather than hundreds of thousands was that this is one of South America’s richest, best-organised countries. It has long experience of dealing with earthquakes.

Seismic activity is common along its Andean ridge. In 1960, it suffered one of the strongest quakes on record. Saturday’s was the third on record with a magnitude greater than 8.7.

Homes and offices are built to sway with seismic waves rather than resist them. “When you look at the architecture in Chile, you see buildings that have damage, but not the complete pancaking that you’ve got in Haiti,” said Cameron Sinclair, executive director of Architecture for Humanity.

Sinclair said Chilean architects have built thousands of low-income houses to be earthquake-resistant. This is required by blueprints and building codes.

Chileans may still be asking themselves whether they did enough to prepare, however. In Concepción, one of the hardest-hit places, many houses made of adobe crumbled, as did a recently built 15-storey apartment block.

The university caught fire, and gas and power lines snapped. Many streets were littered with rubble and, just as in Port-au-Prince, inmates escaped from a damaged prison.

In Santiago, the capital, large sections of the renovated airport’s roof caved in. About 1.5 million Chileans were affected and 500,000 homes severely damaged. In some places, rescuers complained of lack of fuel for equipment.

Even with damage estimated at $15-$30 billion (€11-€22 billion), and airports, motorways and bridges shut, the state responded swiftly.

“The fact that the president [Michelle Bachelet] was out giving minute-to-minute reports a few hours after the quake in the middle of the night gives you an indication of their disaster response,” said Mr Sinclair. – (Guardian service)