What type of plate boundary exists along the coast line near Japan's volcanic mountain ranges?

Question

What type of plate boundary exists along the coast line near Japan's volcanic mountain ranges?

Answer 1

Well, this is what I know.........Japan was formed by two events: subduction resulting in volcanic activity and the opening of the Japan Sea. In the case of Japan, the Pacific Plate and the Philippine Plate subduct the eastern border of the Eurasian Plate. However, the eastern edge of the Eurasian Plate is not the edge of a continent. Because of volcanic activity at such junctions, island arcs are formed in the ocean. Japan is actually composed of four (or five) such island arcs formed by volcanic activity where the Pacific Plate and the Philippine Plate subduct the eastern border of the Eurasian Plate. But, Japan was originally a part of the Asian continental mainland and was separated off from it with the opening of the Japan Sea about 15 million years ago. At this time, subduction of the oceanic plates under the continental plates was already underway. It is thought that subduction can create a back arc basin ahead of the subduction zone. The formation of this basin resulted in the opening of the Japan Sea between Japan and the Asian continental mainland. Subduction and its related volcanic activity continued (and still continues) after the opening of the Japan Sea.  Hope it helps!