These mighty giants rise across the globe—even in the ocean. They typically have steep slopes, sharp or rounded ridges, and a high point known as a peak or summit. Most geologists classify a mountain as a landform that rises at least 300 meters or more above its surrounding area. A mountain range is a series or chain of mountains that are close to each other.
How Are Mountains Formed?
The world’s tallest mountain ranges are formed when parts of the Earth’s crust—called plates—collide in a process known as plate tectonics, causing them to rise like the hood of a car in a head-on collision. The Himalayas in Asia were created by such a massive collision that began around 55 million years ago. Thirty of the highest mountains in the world are found in the Himalayas. Mount Everest, at 8,850 meters, is the highest point on Earth.
The tallest mountain, measured from base to summit, is Mauna Kea, an inactive volcano on the island of Hawaii in the Pacific Ocean. Measured from its base, Mauna Kea stands 10,203 meters tall, although only 4,205 meters rise above sea level.
Volcanic mountains form when molten rock from within the Earth erupts through the crust and accumulates on itself. The Hawaiian Islands were created by underwater volcanoes, and the islands we see above water today are the peaks of those volcanoes. Some of the most well-known volcanoes on land include Mount St. Helens in Washington state and Mount Fuji in Japan. Sometimes, volcanic eruptions break mountains apart instead of building them—like the 1980 eruption that destroyed the summit of Mount St. Helens.
