The Loveliest Little Earthquake ~ Friday Night In Montana

Western Montana has had three earthquakes in the last seven days.  No one I know took note of the first two (each 3.7) but just about everyone in a three town radius felt the 4.5 earthquake Friday night, and many people nearest me (a few miles from the epicenter) heard it as well.

I've experienced earthquakes in a few different states, and at least a few times have felt them when no one else around me did.  I've also felt at least one that I attributed to something else initially, but I would hazard a guess that most of the time when someone is inspired to ask, "was that an earthquake?" there was an earthquake.

Two nights ago was a fairly common Friday night in that I was at home (my blogs about Lyme will illustrate how sadly common this is) and my husband was not (he's a firefighter/paramedic and works a 24-hour shift every third day).

It was uncommon, though in that both of my kids were sleeping in my room, and both in my bed with me.  They have long since grown too wiggly for this, and we seldom attempt it for the sake of all involved.

It is common for us to get sucked into the science channel, but not common that even my youngest is allowed to keep watching until past 11 o'clock (2.5 hours after bedtime).

But we watched just a bit more of just one more show, and as midnight rolled around, a new scuffling round of "move your arm....get off my hair" was beginning just as I was dozing off.

And then the house shook, at first like the trains that pass by our yard, but not quite.  And then the bed shook quite abruptly and unmistakably, but without the walls shaking as much as the trains usually cause.

Bickering and dozing ceased as we all sat straight up, in varying states of wakefulness, and sort of lunged toward a sound we were all hearing while asking, "what was that??"

The unified direction of the lunge, toward a profound rumble that was oddly only beginning as we were lunging, occurred to me only just now.  It's interesting what things you miss that your senses catch.

We all layed back down, and my sons eyes closed the moment his head touched the pillow, and the thought that had been taking shape throughout the event in mind took shape as, "THAT was not a Lyme symptom."  I've been dizzy and off-kilt enough lately that had it not been for my kids, I would have woken up, but assumed I was having yet another weird Lyme moment of many.

It happened just before midnight, and no one else had posted anything....so I asked if my town just shook or just my neighborhood.  Then jumped from USGS to all other earthquake data sites I could find, but no mention of it.

I have very smart friends, and by the time I checked my post it was full of comments from fascinated, sleepy, and frightened people, many of who could already say there was no date up anywhere, and were noticing what I was noticing, which was that it had only been a few days since the last earthquake of notable size in our area, and that this one was the third this week, with two more the previous week near Yellowstone (but both rated less than 2 on the richter scale).  Numerous people noticed the rating (4.5) the moment it appeared on various earthquake data sites.

The knowledge that I live in the Yellowstone Caldera, well within the huge area that eventually (in geological terms, so any time between now and thousands of years from now), will be blown to catachlismic smitherenes doesn't scare me any more than knowing that the Hungry Horse Dam will kill us all if it ever breaks.  That many earthquakes did catch my attention, though.

I have perused the sites in the past---as a biologist with an interdisciplinary cadre of geeky colleagues to egg each other on, who all find interesting data as a result of normal day to day distractions and questions---and have been surprised to see just how many earthquakes happen globally on a regular basis.

Still, it did give me a bit of start to check back to see two 6.7 earthquakes today elsewhere in the world.  That's no reason for alarm at all, but I am surprised we've had 20 in western Montana this month and 894 this year!  The next step is obviously to find a few years of data to compare it to (next time I get curious), and a satisfactory map to insert into this post....