Under the United Nations Convention on the Law of the Sea (UNCLOS), coastal states shall establish the outer limit of the continental shelf beyond 200 nautical miles when coastal states fulfill a number of geomorphological and geological criteria. Coastal states must submit information including scientific data defining the outer limits of the continental shelf to the UN Commission on the Limits of the Continental Shelf (CLCS). Therefore, coastal states need to acquire and analyze large volumes of geological and geophysical data.
To prepare the necessary information by the time limit, which is May 2009 for Japan, survey work, including surveys of crustal structure, bathymetric survey, and ocean bottom sampling, have been conducted under the coordination of an inter-ministerial council.
