Tuesday, May 21, 2013

Tornado death toll lowered

Tornado death toll lowered, Earthquakes and floods constantly crop up in international headlines, but tornadoes often seem like a uniquely American misfortune.

In part, that's true: The United States sees the most tornadoes in the world, with an average of more than 1,000 tornadoes each year. Canada is second, with around 100 per year, and all other countries combined experience another 100 to 200 tornadoes annually. Measuring by land area, the United Kingdom has a higher rate than any other country, but most of the twisters there are relatively weak.

Tornadoes occur when land is wedged between dry air on one side and warm, moist air on another -- exactly the circumstances the central U.S.'s so-called "Tornado Alley" unfortunately finds itself in. Then there's the more obvious reason: The U.S. is really big, and the more land you have, the more likely natural disasters are to strike your country. America's is also a much longer tornado season -- the storms can happen year-round here -- while countries like Bangladesh have brief, turbulent seasons that are just a few weeks long.

But other parts of the world have suffered through their fair share of twisters; every continent has been struck except for Antarctica (where no warm air means no tornadoes). As this map from the National Climatic Data Center shows, other global tornado hotspots include Bangladesh, South Africa, and Europe.

On April 26, 1989, the deadliest tornado ever struck Bangladesh, killing about 1,300 people, injuring 12,000, and leaving 80,000 homeless. Most experts think the extent of the damage was due to a combination of the force of the winds, the poor quality of home construction, and the extremely high population density.

South Africa is blasted by tornadoes during its Boreal summer (when it's winter in the Northern Hemisphere), and one storm that struck the southeastern coastal town of Umtata on December 15, 1998 nearly killed Nelson Mandela. The former South African president escaped injury by laying on the floor of a pharmacy with his bodyguards piled on top of him.

In June 1984, 400 people died in Russia when at least eight tornadoes swept across the western part of the country. Those storms coincided with the sighting of a one-kilogram hailstone, one of the heaviest in the world to date.

And in March, 24 people died and hundreds more were injured when a tornado ripped through China's southeastern Guangdong province, bombarding car windshields with golfball-sized hail.

One reason we hear little about the frequency of tornadoes in other countries could be a lack of record-keeping. (One study from 2000 posited that only 15 percent of French tornadoes are recorded.) More recently, one German scientist estimated that Europe sees 300 or more tornadoes each year -- 130 of which go unreported because they were too brief or made landfall in a sparsely populated area.

Meanwhile, some countries might count 10 separate twisters as one big tornado, so comparing international statistics is tricky, says Jonathan Finch, a meteorologist for the National Weather Service in Dodge City, Kansas.

"We're meticulous here in the U.S.," he said. "If there's a touchdown here, we're going to document it."

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