Earthquake.

YS and I actually experienced our first, and second, earthquake yesterday morning, while cleaning our teeth!

It lasted seconds and we didn't really know what was happening. It was quite an odd sensation; there was just a sort of rumbling, nothing in the house moved or fell over, but we sensed a reverberation of sorts.

DH and ES were oblivious, even though they were in the house too.

Apparently it registered as 5.1 magnitude.