Pacific Ocean closed loop of the andesite line are most of the deep troughs, submerged volcanic mountains, and oceanic volcanic islands that characterize the Pacific basin. Here basaltic lavas gently flow out of rifts to build huge dome-shaped volcanic mountains whose eroded summits form island arcs, chains, and clusters. Outside the andesite line, volcanism is of the explosive type, and 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. The Pacific Ocean is the only ocean which is almost
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