The first one I have felt, anyway.
We were about to sit down to lunch when the rumble came. It was awfully large for a big truck on the street, and the shaking lasted too long for an explosion. Dishes rattled for half a minute. There was no damage.
Our suspicion was confirmed when the phone rang 25 minutes later to advise me of an “unusual event”, the lowest level of emergency classification for a nuclear plant. The next level is “alert”, and I would have had to report to work, a lousy way to spend a beautiful Saturday. The plant is designed to withstand quite large earthquakes without damage, so I’m not worried in the least.
A magnitude 4.2 earthquake had occurred five miles south of Galesburg, Michigan (near Kalamazoo), not quite fifty miles from us. The epicenter was about 3.7 miles down.
I expect opponents of fracking and deep well disposal to make the most of it. Although they may have valid concerns, they need to stick to facts. As usual, I like to do my own research. Here is what I found:
- Oil wells in Michigan sometimes reach 11,000 feet deep. That’s a smidge over two miles. The quake epicenter was nearly twice as far down.
- The deepest waste injection well in the quake area is less than 1-1/2 miles deep.
- Although earthquakes are uncommon in Michigan, a few have resulted in minor damage such as cracked plaster, broken windows, and the occasional toppled chimney. The Kalamazoo area experienced such quakes in 1883 and 1947. Today’s quake was pretty much on schedule, but weaker.
Okay, there’s my research. Don’t trust it. Do your own. A good place to start is earthquake.usgs.gov. Then look up state drilling and well records. This will work wherever you are, so you can check out your local tremors, as well..