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
Warm core ring Warm core ring A warm core ring is a type of mesoscale eddy which breaks off from an ocean current, e.g. the Gulf Stream or the Kuroshio Current. The ring is an independent circulatory system of warm water which can persist for several months. The rest of this article will use the Gulf Stream by way of an example but these mesoscale eddies also form in most powerful ocean currents, such as the Kuroshio or Agulhas currents. Such rings can be detected using infrared satellites or sea height anomalies and are easily identifiable against the surrounding colder waters. These systems