Originally posted by Nineinchnailsmk
im in mid-central illinois right now and about 150 years ago or so there was an earthquake at a fault down in southern illinois which rang bells in philadelphia. supposedly if another of that magnitude were to strick (dont remember the richter scale #) it could possibly level chicago (only because of the tall buildings and the non-earthquake-proofness) i dunno.... CHICKEN LITTLE OVER HERE!!
Actually, it was a series of five earthquakes that struck from 1811 to 1812. These all occured in the New Madrid Fault, and they were the largest earthquakes ever felt in the European history of the U.S. One of the quakes was so strong that the Mississippi River actually flowed backwards for a brief period of time. Now that's some serious action from Mother Nature. Here's a link to more info:
http://wwwneic.cr.usgs.gov/neis/eqlists/USA/1811-1812.html
As for it occuring again, I'd say it's quite likely we'll experience another quake of that magnitude within our lifetimes. When the quake strikes, Memphis, Tennessee and St. Louis, Missouri are going to suffer the most damage. Surprisingly, it's not the tall buildings that you should be worried about. It's all the middle buildings not tall enough to be sky scrapers and too tall to be people's homes.
Take a look at the Mexico City earthquake that struck in 1985. That was a 8.1 on the Richter Scale, and the epicenter was roughly 240 miles away from the city. Yet somehow over 500 buildings were heavily damaged and over 8,000 people were killed. The interesting thing is that the tall buildings and most of the small buildings (depending on their construction) survived without any major damage. Why? Simple. You have to take a look at the actual physics of the ground waves during an earthquake, and a physics term known as resonance (Tacoma Narrows Bridge anyone?). The tall buildings were able to sway with the waves, and most of the small buildings were structuraly uneffected by the waves. The buildings in the middle basically weren't able to keep up with the waves, and down they went. And of course other things will take down the buildings such as rock- and mudslides and the extra shaking from the other already falling buildings (the ultimate destruction of the second WTC tower).
Earthquakes can strike virtually anywhere in the U.S., and they can and will strike someday near your home. This is especially true if you happen to live anywhere near mountain ranges, areas of volcanic activity, and near old fault lines such as the New Madrid and areas in New England near the Canadian border. Even if you live along a coastline you are suspectible to tsunamis that were created on the other side of the body of water, whether it be a lake, bay, gulf, or an ocean.
The best thing you can do is learn if you are in an earthquake risk area, and take the necessary precautions. Earthquake insurance and survival kits are a must if you find yourself near any of those areas. Sure some of you may laugh at the idea of preparing for an earthquake, but how many people do you think were actually ready for the 5.1 last weekend? Now what if that quake was a little more powerful and leveled several towns? Take that one as a warning and be ready for the next one. It may not happen for 90 years or two years, but it will happen, and it may occur right by your home.