Tornadoes are some of the deadliest, most devastating natural phenomena on Earth — but most of us probably have a lot of misconceptions about them. The actual science of tornados is much stranger, and scarier, than you ever knew.
Can a butterfly really trigger a tornado? How dangerous is "Tornado Alley," really? Here are ten things you probably didn't know about twisters
10. The term "Butterfly Effect" was actually conceived of by a meteorologist studying weather models. For the uninitiated, the Butterfly Effect is a concept from chaos theory that states a small change in conditions in a nonlinear system can give rise to enormous changes in that system in the future. The most widely recognized theoretical example of the butterfly effect states that a butterfly flapping its wings in Brazil could lead to a tornado in Texas a few weeks later.
The term, and hence the connection between butterflies and tornadoes, was coined by meteorologist Edward Lorenz in the 1960s, when he discovered that small-scale changes to the starting conditions of a computerized weather model could give rise to wildly disparate (and unpredictable) weather scenarios.
9. It's worth pointing out that butterflies don't really cause tornadoes; rather, the butterfly flapping its wings is said to be part of a larger set of conditions affecting the atmosphere that might ultimately lead to a tornado. In fact, they could just as soon belong to a set of conditions that delay a twister's occurrence, or even stifle one's formation entirely.
8. That said, the butterfly effect isn't all about uncertainty; in fact, NASA uses the butterfly effect to direct the flight path of spacecraft. According to Rutgers biophysicist Troy Shinbrot:
The first example that I know of was the International Cometary Explorer. They used the fact that the butterfly effect applies to trajectories in the solar system. With tiny amounts of hydrazine fuel, they created little puffs that steered the spacecraft halfway across the solar system to meet up with comet Giacobini-Zinner That's how they achieved the first ever scientific cometary encounter.
7. Tornadoes can travel in packs. Such an event is known officially as a "Tornado Outbreak," and is characterized by the formation of at least 6—10 twisters by the same weather system. Maryland actually experienced an outbreak just a few days ago, seeing at least nine confirmed tornadoes over the course of Friday. (As a point of reference, the state's record for most tornadoes in an entire year is 24.)
6. The largest tornado outbreak in history actually occurred last year. Occurring in late April, the storm system persisted for over 3 days, spanned 21 states, and spawned an unprecedented 358 confirmed tornadoes (that's over 20 percent of the total number of tornadoes reported across the U.S. for all of 2011). All told, the outbreak claimed over 300 lives, and caused an estimated 11 billion dollars in damages.
5. For as destructive as it was, last year's outbreak wasn't actually the most violent. See, there's some debate over how to rank tornado outbreaks. Some choose to classify them by the total number of tornadoes. Others rank them according to duration, damages incurred, or lives lost. But when it comes to overall intensity, that title goes to the Super Outbreak of 1974.
Last year's outbreak lasted about four times as long as 1974's, and caused three times as much damage, but the Super Outbreak is unprecedented in its sheer number of large, powerful, and far-traveling tornadoes. On the six point Fujita scale (or "F-Scale," which ranges from F0—F5), 1974's Super Outbreak featured 6 tornados of F5 intensity and 24 were F4. That means that in an 18 hour period, the Super Outbreak gave rise to at least thirty tornadoes with wind speeds in excess of 200 miles per hour.
4. The strongest winds on Earth are thought to occur inside tornadoes. It's difficult to measure them exactly, but atmospheric scientists believe the fastest wind speeds ever were found inside a 1999 tornado in Oklahoma, and clocked in at 318 miles per hour.
3. According to NOAA, wind at those speeds can rip a well-constructed home from its foundations and sweep it away in an instant. An F5 tornado (with wind speeds in excess of 260 miles per hour) has enough oomph to strip a tree of its bark. Even F4 tornadoes have enough power to level houses and pitch vehicles through the air like die cast Hot Wheel cars. Case in point: the semi truck featured here pirouetting in the sky with the lightness of a feather.
2. Tornadoes have been observed on every continent save for Antarctica, but an overwhelming majority of the world's twisters actually take place in a dog-leg shaped region of the United States, aptly dubbed Tornado alley. Why the hell would anyone ever live in Tornado alley? because, all things considered, Tornadoes are actually pretty rare. According to Science News' Sid Perkins:
A typical twister damages an area of only about 13 square kilometers. In a country that boasts almost 9.4 million square kilometers, that leaves a lot of undamaged real estate.
New models suggest that in [Tornado Alley], which stretches from western Iowa down through Nebraska and Kansas to southern Oklahoma and then over Arkansas and Louisiana to southeastern Mississippi, any particular spot can expect on average to wait from 4,000 to 10,000 years between roof-ripping twisters.
1. The deadliest tornado on record? The Daulatpur-Saturia Tornado. It occurred in Bangladesh in 1989, and claimed an estimated 1,300 lives. Bangladesh is one of a handful of places outside of North America where Tornadoes are common.