Let's Twist again

Tornado. A word that to many people means terror, destruction and death.

To me it means fascination because I live in Finland and we don't get tornadoes here. We get long cold winters instead, but given the choice, I'll take a few months of snow and cold over having my house ripped to pieces any day.

I just finished watching a Nova documentary on these bad boys, an thought I'd share with you, since it's Monday, and I have nothing better to blab about. I'll link it at the bottom.

Tornadoes are usually rated on the Enhanced Fujita scale, or EF scale which used to be known as just the Fujita scale. It goes from EF0 meaning topical damage to EF5 which means towns are flattened.

Although tornadoes have been observed on every continent except Antarctica (It's too uniformly cold and dry for them to form there), they are most prevalent in what's known as Tornado Alley in the U.S.

Tornado Alley doesn't have any clear borders but it's core is usually considered to be northern Texas, Oklahoma, Kansas and Nebraska. If you live there you will get to know tornadoes personally.

In the U.S. about 80% of tornadoes are EF0 to EF1, and it's rare for them to last longer than 10 minutes. It's hard to say how often they strike, due to vastly different seasons but also because small local tornadoes aren't always reported, though many are.

Now, since this is Eccentric Spheres we're going to take a look at some extreme ones.

The record holder for biggest tornado is the Tri-State Tornado that rampaged through Missouri, Illinois and Indiana in March 18, 1925. It's records are:

• Furthest path traveled: 352 km (219 miles)
• Longest duration: about 3.5 hours
• Fastest traveling speed: 117 km/h (73mph)

The record holder for most recorded deaths is the Daultipur-Salturia Tornado that ripped through Bangladesh on April 26, 1989. This monster killed about 1300 people, but it should be noted that population centers in Bangladesh are much denser than in Tornado Alley and that their houses aren't built nearly as well.

In fact, efforts are under way to build houses that are better able to withstand the gruesome forces that the large tornadoes produce. An EF5 is as powerful, if not stronger, than the Hiroshima nuclear bomb. But instead of one powerful pulse, an EF5 continuously puts out this unimaginable force as it travels along.

The biggest difficulty in designing houses that are capable of resisting these wind speeds aren't just the costs involved but the fact that as a tornado approaches, your house is first beset by a powerful pushing force, but when the tornado is close, it exerts a pulling force instead and this is no joke. On May 22, 2011 in Joplin, Missouri (featured heavily in the documentary I mentioned) the EF5 grabbed the local hospital, not a small clinic mind you, but a large hospital and twisted the entire building four inches off it's own foundation!

Luckily only about 1% of tornadoes are EF5's and it's unusual for them to hit towns or cities but, as communities grow and multiply it becomes increasingly likely that they get hit.

I have had a fascination with powerful natural disasters like tornadoes since I was a child, and I can sometimes sit for hours and watch storm chaser footage on Youtube. Indeed that's how I found this documentary. 

 https://www.youtube.com/watch?v=IUj9OW_OXmU

If you're interested in the subject matter, do give it a shot. It's pretty good, with really nice CGI explaining how tornadoes are formed, but for all non U.S. readers, be advised that it is very American in style with long dramatic pauses “in order to ------ save lives!”

I hope you have a great week and don't get blown away. Until next week!