The U.S. Energy Information Agency estimates that the South China Sea holds about 190 trillion cubic feet of natural gas and 11 billion barrels of oil in proved and probable reserves, most of which lie along the margins of the South China Sea rather than under disputed islets and reefs. The U.S. Geological Survey in 2012 estimated that there could be another 160 trillion cubic feet of natural gas and 12 billion barrels of oil undiscovered in the South China Sea. The energy blocks in question are detailed in the interactive map provided in this article by CSIS.