Geological conditions suggesting possible reserves of a next-generation energy source called methane hydrate were found at about 225 locations in the Sea of Japan off Niigata and Ishikawa prefectures, according to a government survey.

The Ministry of Economy, Trade and Industry plans to conduct test drilling at those locations in fiscal 2014 to extract samples. Methane hydrate, comprised of methane gas and water, is believed to exist in a wide area of seabed surrounding Japan.

Japan succeeded in extracting natural gas from methane hydrate in the seabed in the Pacific Ocean off Aichi Prefecture in March, but has lagged in tapping the resource in the Sea of Japan.

METI started its full-fledged study in the Sea of Japan in June, with the National Institute of Advanced Industrial Science and Technology and other bodies conducting the actual research.

The research, including sonic surveying, covered about 8,260 sq. km of seafloor off Jyoetsu, Niigata Prefecture, and 5,950 sq. km of seabed off the Noto Peninsula, Ishikawa Prefecture.

The ministry will continue research for about three years to assess the amount of reserves in the Sea of Japan. It will check the seabed off Akita, Yamagata and Shimane in fiscal 2014 and off Hokkaido, Akita and Yamagata in fiscal 2015.