― Underwater volcanoes still save a lot of mystery. Therefore, the location and the wide spread it difficult for researchers to study it. Though the intensity of the underwater volcanic eruption reached 75 percent of all volcanic eruptions on Earth. ∙ In Indonesia, of the 129 volcanoes, there are five which are underwater volcano, including Mount Sub Marine, which erupted in 1922, and Mount Banuawalu, erupted in 1919. Both are located in North Sulawesi waters. ∙ In addition, in the [...].