“Methane hydrate is a sherbetlike substance that can form when methane gas is trapped in ice below the seabed or underground. Though it looks like ice, it burns when it is heated. “
“Jogmec estimates that the surrounding area in the Nankai submarine trough holds at least 1.1 trillion cubic meters, or 39 trillion cubic feet, of methane hydrate, enough to meet 11 years’ worth of gas imports to Japan.
A separate rough estimate by the National Institute of Advanced Industrial Science and Technology has put the total amount of methane hydrate in the waters surrounding Japan at more than 7 trillion cubic meters, or what researchers have long said is closer to 100 years’ worth of Japan’s natural gas needs.
“Now we know that extraction is possible,” said Mikio Satoh, a senior researcher in marine geology at the institute who was not involved in the Nankai trough expedition. “The next step is to see how far Japan can get costs down to make the technology economically viable.” “