I live in Southern California and I don't worry.
There are about 26 earthquakes a day here, but the vast majority of them are pretty small. A truck driving up the street has more affect on vinyl playback than any of these earthquakes.
Now, if there is an earthquake large enough to affect vinyl playback in my house, there probably is more to worry about than one messing up the playback of an Alan Holdsworth guitar solo or an Elliot Carter chamber work, although with the latter, I might not notice the difference
