Since the eruption of Nishinoshima volcano and a resultant newborn island in the Ogasawara Islands was confirmed on November 20, 2013, the effusive outflow of lava over two years has greatly increased the size of the island. A bathymetric survey around the island carried out by the Japan Coast Guard in the summer of 2015 revealed that this eruption of Nishinoshima volcano was one of the largest domestic eruptions in terms of expelled volcanic material since the end of World War II. As the broad extent of Japan's jurisdictional waters is dependent on volcanic islands, observation activities are important not only for the safety of residents and navigation, but also from the perspective of the delimitation of Japan's jurisdictional waters.
Selected Papers No.21

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