WHAT DOES THE MAP SHOW? The USGS Volcano Hazards Program combines maps and information about hazards to allow emergency managers and the public to visualize the status of volcanoes around the world. The map-based interface allows users to understand the danger posed by each volcano in relationship to the people and places surrounding it.
THE RING OF FIRE: Over 75 percent of the world's volcanoes fall within the so-called "Ring of Fire," circling from South America, to Alaska, to Japan, and on to New Zealand. Most volcanoes are located at the boundary of tectonic plates, which are massive slabs of the Earth's crust that move slowly over what is called the asthenosphere. In the Pacific region, a great number of volcanoes occur where one plate dives below another. As the plate drops deeper it sets in a motion the process that creates lava. The molten lava then begins to rise through the solid rock above and create volcanoes.