I was surprised, to say the least, to read about a strong earthquake tonight close to the Cayman Islands (20 miles southeast of Georgetown, the capital). Actually, there are a number of surprises for me here and I might as well run them down.
Though I knew there are plates upon which all of the Earth’s surface floats, I didn’t realize there was a boundary between two plates in the Caribbean. They grind against each other slowly, but constantly. The relative motion is only 6/10″ per year.
Of course one year is nothing to the Earth. Over 20 years that’s around a foot of motion. Over decades and centuries… well, you get the idea.
At some point something’s gotta give… and it did tonight. The quake was magnitude 6.7¹. That’s enough to be very scary and even more destructive. I have not yet heard any damage reports from the Caymans. Magnitude alone is not enough to predict destruction.
My second surprise was seeing actual ‘shock reports‘ from the Cayman Islands. This is actually an interesting idea from the United States Geological Service. They ask people to check in and rate the quake! It’s like Dick Clark on American Bandstand circa 1965.
As I type this there are 189 reports from the Caymans and one from Haiti. Each locale is averaged to show how the quake was felt.
I think the USGS does an amazing job keeping up with earthquakes. Their website is fast and thorough. I’m a math and science guy, so it appeals to me more than most. Still, if you’re curious, it’s worth looking at.
And, to get my own little plug in, there’s a link to the most recent large earthquake in the column on the right: Latest Large Earthquakes Worldwide.
¹ – Remember Richter? The Richter scale is no longer in use by geologists.