The 1979 (or second) oil crisis or oil shock occurred in the United States due to decreased oil output in the wake of the Iranian Revolution. Despite the fact that global oil supply decreased by only ~4%, widespread panic resulted, driving the price far higher than justified by supply. The price of crude oil more than doubled to $39.50 per barrel over the next 12 months, and long lines once again appeared at gas stations, as they had in the 1973 oil crisis.