How many active volcanoes are there in the world?
There are about 1500 potentially active volcanoes worldwide, aside from the continuous belt of volcanoes on the ocean floor. About 500 of these have erupted in historical time. More than half of these volcanoes are part of the Ring of Fire, a region that encircles the Pacific Ocean. In the U.S., volcanoes in the Cascade Range and Alaska (Aleutian volcanic chain) are part of the Ring, while Hawaiian volcanoes form over a 'hot spot' near the center of the Ring.