The entire chain of mountains that runs from the Andes of South America to the fjords of British Colombia and Alaska is actually caused by the Ring of Fire. These mountains also include the Sierra Nevada range. The tectonic movements of the Earth's plates caused by eruptions in the Ring of Fire are slowly pushing the Pacific plate up against the North American and South American plates, causing mountains to form much as pushing two edges of paper together causes them to crumple and become raised.
The Ring of Fire also causes the formation of active volcanoes that are created when molten lava bubbles up from under the Earth's crust and shoots to the surface, forming the distinct cones of volcanoes. Mount St. Helens, in southern Washington State, is a good example of these phenomena, as are the large volcanoes of Mexico, Central America and Japan. These are the areas of the most intense activity caused by the Ring of Fire.
Island chains, like Hawaii, the Philippines and the Aleutian Islands, are also caused by the Ring of Fire. These island chains are composed of the underground lava flows that bubble up and create volcanic mountains, then calm down for a while before erupting again. In the meantime, the Pacific plate continues to shift and move, meaning that each time the lava bubbles up it is in a slightly different place, causing the "strings" of islands that are actually caused by the same underground vent.
Just as the Ring of Fire pushes plates together, creating mountain ranges, it also pulls them apart, creating huge trenches that are mainly underwater and not visible to most people. The huge Aleutian Trench reaches depths of more than 25,000 feet below sea level and was created by the Ring of Fire's movement in what is known as a subduction zone.
