Tohoku was an exceptional event and this may explain why Goce, on this occasion, was able to pick it up.

BBC: Japan quake 'heard at edge of space'

"White Turf is an exceptional event, " said the event's president, Silvio Staub.

CNN: Cool racing: Horses battle on snow

"I think we all realise that the riots were an exceptional event but it's the case that if, for instance, a gang raids a bank then that counts as one crime even if there were four people in that gang, " he said.

BBC: More crimes added to police mapping website