..you can watch the live seismic recorders around Yellowstone Park in the US as they monitor the 'swarm' of earthquake activity that started over Christmas, on 27th December. HERE.
Doom mongers in the US are fearful the dormant volcano could blow, sending several square miles of dust into the atmosphere, endangering life on Earth etc.
I'll bet the train operator already has a pre recorded announcement ready
"South Eastern trains apologise for the cancellation of this service due to apocalyptic volcanic activity and regrets any delay or inconvenience this may cause to your journey ..."