When the Apartment Shakes: The May 2, 2015, Michigan Earthquake

About twenty minutes after noon yesterday, as I was sitting in my couch, unperturbed as a turtle on tranquilizers, suddenly my apartment began to shake and rattle, and an indescribable sound filled my ears. My first thought was "What the . . . ? What the devil is my downstairs neighbor doing?" If he was rearranging furniture, then he was doing it with an earthmover. The shaking continued for ten seconds, maybe fifteen. Then it quit, just like that. It took me a few seconds to grasp the obvious: I think we've just had an earthquake. That's what it was: a 4.2-magnitude earthquake centered 3.5 miles below the earth's surface about forty miles south of me near Galesburg, Michigan. If a 4.2 quake doesn't sound impressive to those of you on the West Coast, it nevertheless was enough to generate interest around these parts. I myself was mildly surprised, or so I surmised from the fact that my eyeballs had protruded three inches from their sockets and required repositioning. Somewhere in my reading on the event yesterday (I can't relocate the source), I learned that, due to geological differences between the West Coast and the Midwest, quakes in this region tend to be shallower, but the energy they expend is often felt more intensely across a larger area. Yesterday's quake might have rattled a few coffee cups in San Francisco, but here in West Michigan, it actually caused isolated instances of light structural damage: fractures in the outer walls of a few buildings, cracks in an asphalt parking lot, and fissures in the earth spewing magma as prehistoric reptiles emerged from subterranean caverns.* Michigan is hardly the nation's earthquake capitol. This isn't a region thick with active faults. Still, we do get the very occasional rumble. The largest in Lower Michigan's recent history was a 4.6-magnitude quake that occurred on August 10, 1947. Rated VI on the Modified Mercali Intensity scale (MMI), that one, also centered in roughly the same area as yesterday's, brought down a few chimneys and did some other notable damage. By comparison, yesterday's quake merited a V on the scale. The MMI scale describes a V thus: "Felt by nearly everyone; many awakened. Some dishes, windows broken. Unstable objects overturned. Pendulum clocks may stop." Yeah, that sounds about right. People felt this quake all across Lower Michigan, from Holland to Grand Rapids to Saginaw, and as far west as Chicago and as far east as northern Ohio. In other words, it was no small deal. Amazingly, it still escaped some people's notice. Not mine, though. I've walked through a number of smaller quakes without ever knowing about them till later in the news, when I'd hear reports of so-and-so noticing the china rattling in their cabinet. I always felt a bit disappointed, robbed of an experience through failure to have a china cabinet on hand when I needed one. But as of yesterday, I can finally say that I've lived through an earthquake—the Great Galesburg Earthquake of 2015. "Great" is of course a relative term. If you live near the San Andreas Fault, yesterday's episode would have seemed like a gnat fart. But it was pretty great for West Michigan. It caused no real harm, but it left plenty to talk about and a cool memory.
* Parts of this statement may require verification.