Here on the east coast, the geology is relatively stable. It's very old and cold dense rock. We rarely get noticeable earthquakes, but when they're any real size, they get carried far and wide. In California, a 5.8 isn't that unusual, but it would be fairly localized. Here, we felt it all up and down the east coast, from at least the Carolinas up into Canada. That's what, 1000 miles or more?