Earth Tremors!

I've been getting on with my latest bear over last couple of days. This morning I was just beginning to wax the nose when I was suddenly stopped in my tracks by the loudest booming noise in the house that I have ever heard! I froze to the spot, the cats jumped up from their napping positions to the floor and were so wide-eyed, I dropped my bear on the table and ran to see what on earth had happened upstairs. My sister-in-law came rushing down at the same time to see if I knew what had happened and we had shocked and puzzled looks on our faces both declaring "What the h*** was that?"
We ran all around the house, looked outside but there was nothing obvious but other people on the street were doing the same. I concluded it must have been something like a gas explosion somewhere not too far away.
My sister-in-law called me about 2 hours later to say it had been announced on the radio that there had been an earthquake in Ulverston (approx 20 miles across the bay) measuring 3.7 on the richter scale! It's the first time in my life I have felt any signs of an earthquake - 3.7 is very mild but I felt so panicked by the house shaking and creaking at that level that it realise how horrific it must be to experience a much stronger quake!