Before the advent of the plates and tectonics theory, geologists noted the concentration of volcanoes around the boundaries of the Pacific Ocean and called it the Pacific Ring of Fire. But now we know that the Ring of Fire coincides with the plate boundary.

The 500 to 600 active volcanoes around the world are not randomly distributed but they show a distinct pattern. About 80 percent are found at the boundaries where plates converge and 15 percent are found where the plates separate. The remaining are found within the plates.

It should be noted that there is some volcanic activity that is associated with midoceanic ridges nor with subduction zones. The island of Hawaii, for example, lies in an archipelago near the middle of the pacific plate. Lava poured from one of its volcanic mountain, Kilauea repeatedly during the 1970s and almost continuously during the 80s and early 1990s. On the African plate where West Africa and Equatorial Africa meet, lies Mount Cameroon, another active volcano far from spreading ridges and subduction zones. Other examples can also be found. There are some particular belts that have been identified as having volcanoes.

The Circum Pacific Belt is one. The belt circumscribes the Pacific Ocean. This area is essentially the pacific plate. In this region, the chain of volcanoes extends for almost 3200 km from the Aleutian Islands into Kamchatka, Japan to Philippines and Indonesia, southwards into the Pacific islands of Solomon, New Hebrides, Tonga and New Zealand. On the other side of the Pacific, the chain continues from the Andes to Central America, Mexico and right up to Alaska.

Next is the Eurasian Belt which consists of Italy and Eastern Mediterranean regions. Volcanoes of this region are mainly associated with Alpine folds e.g. Vesuvius, Etna, Stromboli etc. This belt spreads through Italy and then goes from Armenia, Iran, Pakistan to Burma.

The last is the Atlantic Belt which consists of West Indies and the islands of Eastern Atlantic from Iceland to St. Helena which are all of volcanic origin.