Immediatley after it happenned, my brother who lives about 2.5 km's away from us, phoned me and asked if our house also shook. He said his cupboard doors and glasses were rattling. We, didin't have any shaking or even any vibrations. We both live on the same hill and the area is full of granite rock.
My other brother was about 7 km's away and didn't hear or feel anything.
Now, we live in an area which has never had an earthquake, the only one was in 1969 and about 250 km away, so I have no idea what it feels like or sounds like.
The nearby military base also has planes very often going over this, so I don't know if it's a "sonic boom" because I've also never experienced that.
Could this have been an earthquake?