Rumbles and Tremors

[The_Steed]

There is another thread running about mysterious rumbles and tremors here;

http://www.pprune.org/spectators-bal...buildings.html

And last night, there were widespread reports in the Aberdeen area of more mysterious rumbles and tremors;

BBC News - Tremor reports on Aberdeenshire coast 'not earthquake'

Is it as simple as RAF planes dashing about practising for the Olympics? Or can the conspiracy theorists get excited about the potential for a new US 'Aurora-esque' craft being on the go and sonic booming everyone?