Earthquakes

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We in California are used to small tremors. It's pretty common.

Recently, we have been getting lots and lots of news on Haiti and now Chile. I thought I would post this short message just to give you an idea on the difference between the size of earthquakes as they occur on the Richter scale.

According to the US Geological Service, an earthquake is amplified in magnitude ten times per whole number on the scale. (http://earthquake.usgs.gov/learn/topics/richter.php) In energy released though, each whole number is 31 times greater. That means, of course, that a 4.0 is ten times greater than a 3.0 in magnitude and 31 times greater in energy released.

Now let's compare Haiti 7.0 to Chile at 8.8. Simple subtraction gives us a 1.8 difference. That means that in amplitude Chile was 18 times greater than Haiti but in energy released, it was just short of 56 times greater. Whew!

The Haiti quake of Jan 12th lasted 30 to 40 seconds according to wiki.answers.com, but I heard on the news this morning that the Chile quake from Saturday lasted almost 3 minutes. Wow! If you've ever been through a quake, 30 seconds is an eternity.

Close your eyes and try to imagine that 3 minutes.
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