Alaska Orders Review of All North Slope Oil Wells After Spill Linked to Permafrost

Alaska's main oil and gas regulatory body has ordered a review of all North Slope wells after a spill last spring was connected to thawing permafrost, subsidence and a cracked casing.

The emergency order, issued Monday by the Alaska Oil and Gas Conservation Commission (AOGCC), said the outer casing that cracked had been set in the permafrost.