I'm in Bolton and got my teeth rattled by it, so it was easy to be sure I hadn't imagined it. My very first impression was that for some reason giant and very, very heavy invisible people were vigorously consummating their love on our stairs, then I realised oh, it's the whole house shaking. Then Pol, who is a veteran of quakes told me in a blase fashion what it was. Apparently Scotland gets tremors reasonably frequently but we don't hear about it because there it's not news. Or something.