Geology of the Pacific Ocean Guinea, and New Zealand lie outside the andesite line. Outside of the andesite line, volcanism is explosive; the Pacific Ring of Fire is the world's foremost belt of explosive volcanism. The Ring of Fire is named after the several hundred active volcanoes that sit above the various subduction zones. In 2009, the deepest undersea eruption ever recorded occurred at the West Mata submarine volcano, a mile beneath the ocean, close to the Tonga-Kermadec Trench, within the Ring of Fire; it was filmed by the US Jason robotic submersible which descended over . The Pacific Ocean is the only ocean which
Geography of the Philippines The boundaries of the Philippine archipelago are described in Article III of the Treaty of Paris (1898), as comprising an irregular polygon. A box enclosing that polygon would have corners at 20°N 116°E, 20°N 127°E, 4.75°N 127°E, 4.75°N 116°E. The center of this box would lie at 121.5 E, 12.375 N. That point lies roughly in the center of the Tablas Strait between the islands of Tablas and Mindoro. "Republic Act No. 9522", "An Act to Define the Baselines of the Territorial Sea of the Philippines", describes an irregular polygon which fits within a box with its center at 121°44'47.45"E