In a move to get closer to developing its own domestic fossil fuel, Japan is extracting natural gas from an offshore deposit of methane hydrates. The tests that are set to run until the end of this month mark the first time such production methods have been tested in a deep-sea formation.

Methane hydrates—frozen deposits of the main ingredient in natural gas found in ocean sediments and near permafrost—are thought to be abundant. Worldwide, such deposits contain about 35 percent more gas than other reserves. In Japan, offshore deposits could supply the country with 100 years of natural gas, say researchers.