The 33-year-old actor, who is married to Demi Moore, was apparently spotted spending $4,000 (£2,500) at Los Angeles' Surplus Value Center on survival gear.
An insider told In Touch magazine, 'He is obsessed with the idea of either an earthquake or massive uprising and the store specialises in anything you might need for basic survival in the event of a natural disaster.'
The former Punk'd star is said to have stocked up on emergency blankets, hand-powered radios and flashlights, along with emergency water rations and ready-to-eat meals.