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 creates volcanoes.
ABOUT HURRICANES: A hurricane is a type of tropical cyclone, a low-pressure system that usually forms in the tropics and has winds that circulate counterclockwise near the earth's surface. Storms are considered hurricanes when sustained wind speeds surpass 74 MPH. Every hurricane arises from the combination of warm water and moist warm air. Tropical thunderstorms drift out over warm ocean waters and encounter winds coming in from near the equator. Warm, moist air from the ocean surface rises rapidly, encounters cooler air, and condenses into water vapor to form storm clouds, releasing heat in the process. This heat causes the condensation process to continue, so that more and more warm moist air is drawn into the developing storm, creating a wind pattern that spirals around the relatively calm center, or eye, of the storm, much like water swirling down a drain. The winds keep circling and accelerating to form a classic cyclone pattern.
The American Meteorological Society and the American Geophysical Union contributed to the information contained in the TV portion of this report.