I live in Southwest Michigan, about 15 miles south of Kalamazoo. Today, we had an earthquake of magnitude 4.2.
I live across the street from the houses next to the train tracks. It is an active freight line and big, heavy trains can shake the house. This shaking was much different. We have 5 crossings through town and federal law requires them to blow the horn at each crossing. The Wednesday night, AD&D campaign I play in can hear the whistles if I forget to mute my microphone until they pass. If the windows are open in warm weather, I have people in phone calls ask me if I am standing on the tracks.
I was in my house, built about 1920 on sandy soil. The shaking was slightly similar to a big, heavy train going by, but it felt deeper and more powerful, and lasted just a few seconds.
I swore I heard a boom/roar/loud noise that preceded/coincided/followed the shaking. I can’t explain that. It was over so quickly that I didn’t have time to make sense of it. My thoughts were, there is no train, did a tanker truck explode? That has to be an earthquake.
About ten or fifteen minutes later, there was a very brief aftershock.
This is the first earthquake that I know I’ve experienced. My recollection is that an earthquake needs to be a 2.5 to 3.0 for most people to feel it and know it’s an earthquake. What I found using my google-fu is that it has to be a 3.0 to notice it.
A 4.2 was interesting. Since the scale increases an order of magnitude, a 5 would be impressive! A 6, 7 or more would be mind blowing.
My son took his girlfriend and their daughter to a neighborhood garage sale and met up with some friends. He said that he was sitting on the ground and that the ground beneath him felt hollow. His girlfriend said that she was standing up and that her feet were vibrating and she noticed that the trees were moving one direction and the houses another. Their daughter is 3 1/2 months old and she did not seem to have any reaction.
In addition to an interesting experience, I have a better understanding and thus more able to describe an earthquake in my writing and DMing.