Late, last night while I was asleep, watching recorded TV (Poh's Kitchen actually) I was rudely awakened by a great thump, the windows shook and it sounded like a million possums galloping over the roof. After a few expletives along the lines of "what was that" or similar, the Mr and I decided that it was an explosion, we went outside, nothing was stirring, no sirens, no noise, nothing. We went back inside, Cody looked a little bewildered, wondering what all the fuss was about, the birds were silent.
A bit later, lying in bed, listening to Nightlife on ABC radio, we were talking about it and wondering (as you do) what it was, just after I said "well if it wasn't an explosion, perhaps it was an earthquake" the radio programme switched back to the Adelaide station and we heard that it was an earthquake (3.8 magnitude).
I haven't felt an earthquake since I lived in Wellington, NZ where they were a relatively common occurrence and unless it was a really big one no one remarked on it. Perhaps it is now time for me to make up an earthquake kit (similar to a bushfire kit) I always had two in Wellington (one at home and one at work).