Like the one we had in Lawton OK when I was a kid---everybody around there is used to the earth moving, and I slept through it. [The atomic cannon would blow all our kitchen cabinets open.] I was so disappointed---I'd WANTED to experience an earthquake.
I finally got my chance, of places, in Spokane. We had our 4.3, from a fault that hadn't moved in years---all those old pacific islands that make up Washington are still jostling against the dock, it seems.
So you've got something going on down in the depths of the Gulf---an old crack from the dino-killer asteroid, maybe?