Open Image ModalThe finder-installed power grab (FPG), left, and on-board drilling machine system, center, sit on Japan Oil, Gas and Metals National Corp.'s (JOGMEC) marine resources research vessel, Hakurei, berthed at a pier in Tokyo, Japan, on Wednesday, March 21, 2012. The vessel started exploring the country's exclusive economic zone last month for cobalt-rich crusts and methane hydrate, which it hopes will become a promising energy source, state-owned JOGMEC said today. Photographer: Kiyoshi Ota/Bloomberg via Getty ImagesBloomberg via Getty Imagesこのエントリは、期限切れになった関連記事