[HGM04-P03] Geomorphological mapping of the continental shelf around the Japanese Islands based on the interpretation of submarine anaglyph images
Keywords:geological disposal technology, seafloor landform, continental shelf, anaglyph, geomorphological map, Japanese Islands
Submarine geomorphological map displays shelf breaks, significant breaks of slope, submarine canyons, and submarine terraces. The shelf breaks were defined as the most seaward convex slope break around the transitional zone between the continental shelf and slope; this definition differs from “Quaternary map of Japan” (Japan Association for Quaternary Research ed., 1987). Submarine canyons were classified in terms of whether they dissect the continental shelf or not. These two geomorphic elements were transferred into shape files (data format for geographic information system) as this will enable quantitative analyses of the landforms present on the submarine geomorphological map.
Submarine geomorphological map provides basic information concerning the geomorphic features of the Japan’s continental shelf. This information is as follows: (1) regional difference of the continental shelf and its depths, (2) distribution of the area, where the extent of continental shelf is constrained by the dissection front formed by submarine canyons and submarine landslides, and (3) distribution of submarine terraces. The future subject of submarine geomorphological mapping is to conduct the identification of submarine active faults, shelf channels, and tidal landforms. Moreover, it will be expected to construct the geomorphological map seamlessly connecting terrestrial area to marine area by incorporating marine terraces and active faults shown in the previous studies into the submarine geomorphological map.
This study was carried out under a contract with METI (Ministry of Economy, Trade and Industry) as part of its R&D supporting program for developing geological disposal technology.
Japan Association for Quaternary Research ed. (1987) Quaternary map of Japan, University of Tokyo Press.