One of the major objectives of seafloor exploration is to discover and study "resources lying dormant at the bottom of the sea."
As everyone is aware, the massive consumption of petroleum and natural gases is deeply connected to environmental problems such as global warming. Therefore what is now required is the development of new resources that pose minimum burden on the earth environment. One of these new resources, methane hydrate is the most well known.
Methane hydrate is a chemical compound containing methane and water molecules in its structure and is known as "burning ice" on account of its appearance and nature. The amount of CO2 produced during combustion is half of that of petroleum and hopes are high for this compound as a new source of energy, which may also be effective as an anti-global warning measure. Almost all of the earth's supply of methane hydrate is believed to exist somewhere few hundred meters below the seafloor and the seas off Japan are thought to have the world's richest deposits of methane hydrate.
In 2005 JAMSTEC discovered methane hydrate exposed in the waters approximately 30km off the cost of Joetsu-shi in Niigata prefecture. JAMSTEC also discovered, by using the method of emitting weak electrical currents on the seafloor and surveying the electrical resistance of the seafloor formations, that a substance believed to be methane hydrate extended from the surface of the seafloor to a depth of 100m or so beneath seafloor. Depending on future R&D, it may become possible to mine and commercialize the substance.
In addition to methane hydrate, the seafloor is believed to be a mine of methallic resources including nickel, manganese and cobalt.

A chemical synthesis ecosystem found in the Indian Ocean, 2,450m below the sea surface. (©JAMSTEC)

In certain parts of the seafloor with busy volcanic activity, water heated up by the earth's magma can be seen spurting out of the volcanoes. Known as hydrothermal vents, they are also called chimneys because they protrude from the seafloor like chimneys. According to Mr. Matsumoto, they are one of the most beautiful sights in the deep sea. Although the hot water spewing out of these vents contain sulfuric compounds, methane, heavy metals and other substances, which would be toxic to living organisms under normal circumstances, this particular area of the deep sea is characterized by an abundance of living organisms, compared to other areas. These living organisms belong to what is known as the chemical synthesis ecosystem, where organic nutrients are formed from chemical substances without the help of light. Since the environment surrounding the chimneys is thought to be similar to the environment at the time of the earth's formation, the study of the chemical synthesis ecosystem is also expected to unravel some of the mysteries of the beginning of life on earth. It could also lead to the discovery of useful microorganisms currently unknown to man.
In order to secure these various undersea resources, the Japanese government filed a petition to the UN in November 2008 to have the nearly 740,000 square kilometers of the seafloor, which is twice the territorial area of Japan, recognized as part of Japan's continental shelf. If recognized, Japan will acquire exclusive rights to the development of natural resources lying on and beneath the seafloor. The research vessel, Kaiyo, and the deep-sea research vessel, Kairei, on which Ms. Mizota conducted her research, played major roles in the studies of the crustal structure, which became the basis of these claims.