The mighty chunks rise all over the world, including the oceans. They usually have steep, sloping sides and sharp or rounded ridges, and a high point, called a peak or summit. Most geologists classify a mountain as a landform that rises at least 1,000 feet (300 meters) or more above its surrounding area. A mountain range is a series or chain of mountains that are close together.
How Are Mountains Formed?
The world's tallest mountain ranges form when pieces of Earth's crust—called plates—smash against each other in a process called plate tectonics, and buckle up like the hood of a car in a head-on collision. The Himalaya in Asia formed from one such massive wreck that started about 55 million years ago. Thirty of the world’s highest mountains are in the Himalaya. The summit of Mount Everest, at 29,035 feet (8,850 meters), is the highest point on Earth.
The tallest mountain measured from top to bottom is Mauna Kea, an inactive volcano on the island of Hawaii in the Pacific Ocean. Measured from the base, Mauna Kea stands 33,474 feet (10,203 meters) tall, though it only rises 13,796 feet (4,205 meters) above the sea.
Volcanic mountains form when molten rock from deep inside the Earth erupts through the crust and piles up on itself. The islands of Hawaii were formed by undersea volcanoes, and the islands seen above water today are the remaining volcano tops. Well-known volcanoes on land include Mount St. Helens in Washington State and Mount Fuji in Japan. Sometimes volcanic eruptions break down mountains instead of building them up, like the 1980 eruption that blew the top off Mount St. Helens.
When magma pushes the crust up but hardens before erupting onto the surface, it forms so-called dome mountains. Wind and rain pummel the domes, sculpting peaks and valleys. Examples include the Black Hills of South Dakota and the Adirondack Mountains of New York. Plateau mountains are similar to dome mountains, but form as colliding tectonic plates push up the land without folding or faulting. They are then shaped by weathering and erosion.
Other types of mountains form when stresses within and between the tectonic plates lead to cracking and faulting of the Earth's surface, which forces blocks of rock up and down. Examples of fault-block mountains include the Sierra Nevada in California and Nevada, the Tetons in Wyoming, and the Harz Mountains in Germany.
Impact of Mountains on Habitats and Geopolitics
Mountains often serve as geographic features that define natural borders of countries. Their height can influence weather patterns, stalling storms that roll off the oceans and squeezing water from the clouds. The other side is often much drier. The rugged landscapes even provide refuge—and protection—for fleeing and invading armies.
Related Topics
You May Also Like
Go Further
Animals
- Cougar travels 1,000 miles in one of longest recorded treksCougar travels 1,000 miles in one of longest recorded treks
- Rare gray whale spotted in the Atlantic—and it's only the beginningRare gray whale spotted in the Atlantic—and it's only the beginning
- Why 'funga' is just as important as flora and faunaWhy 'funga' is just as important as flora and fauna
- Termite fossils prove mating hasn't changed in 38 million yearsTermite fossils prove mating hasn't changed in 38 million years
Environment
- Why the 2024 hurricane season could be especially activeWhy the 2024 hurricane season could be especially active
- Mushroom leather? The future of fashion is closer than you think.Mushroom leather? The future of fashion is closer than you think.
- This deadly fungus is hitchhiking its way across the worldThis deadly fungus is hitchhiking its way across the world
- Why 'funga' is just as important as flora and faunaWhy 'funga' is just as important as flora and fauna
- This exploding mine holds a treasure that may change the worldThis exploding mine holds a treasure that may change the world
History & Culture
- See the story of Jonah and the whale like never beforeSee the story of Jonah and the whale like never before
- This ancient mosaic offers extraordinary insights into the pastThis ancient mosaic offers extraordinary insights into the past
- These are the real dunes that inspired Dune—and you can visit themThese are the real dunes that inspired Dune—and you can visit them
- Meet the only woman privy to the plot to kill Julius CaesarMeet the only woman privy to the plot to kill Julius Caesar
Science
- Women’s bodies are understudied—but that’s starting to changeWomen’s bodies are understudied—but that’s starting to change
- Hundreds of tiny arachnids are likely on your face right nowHundreds of tiny arachnids are likely on your face right now
- What's worse than a hangover? Hangxiety. Here's why it happens.What's worse than a hangover? Hangxiety. Here's why it happens.
Travel
- A guide to Gdansk, Poland's regenerated maritime cityA guide to Gdansk, Poland's regenerated maritime city
- A taste of West Bengal, from curries to Kolkata street foodA taste of West Bengal, from curries to Kolkata street food