A plateau is an extensive area of relatively flat, elevated land that rises sharply above the surrounding terrain on at least one side. Also called a tableland, a plateau is defined by two features working together: a broad, level (or gently rolling) summit surface and at least one steep edge or escarpment that separates it from lower ground. Plateaus form through tectonic uplift, layered volcanic eruptions, or the erosion of softer surrounding rock, and they cover roughly a third of Earth's land surface, ranging from a few square kilometers to millions.
What Is a Plateau?
In physical geography, a plateau (from the French plat, meaning "flat") is one of the four major landform types, alongside mountains, plains, and hills. What sets a plateau apart is the combination of height and flatness. Unlike a mountain, whose summit comes to a peak or ridge, a plateau has a wide, table-like top. Unlike a plain, which sits close to the surrounding land, a plateau stands distinctly above it, bounded by cliffs or steep slopes on one or more sides.
Plateaus can range from a few hundred meters to over 5,000 meters in elevation. The defining escarpment may be the result of faulting, erosion, or the abrupt edge of an old lava field. Because their surfaces are elevated yet level, plateaus often become the headwaters region for major rivers, which then cut downward into the rock to create dramatic gorges, the most famous being the Grand Canyon carved into the Colorado Plateau.
How Plateaus Form
Geologists classify plateaus largely by the process that created them. Three mechanisms dominate:
- Tectonic uplift (continental collision): When two continental plates collide, the crust thickens and is forced upward over millions of years. The Tibetan Plateau is the classic example, raised by the ongoing collision of the Indian and Eurasian plates.
- Volcanic activity: Successive flows of fluid basaltic lava spread across the land and solidify into broad, layered sheets. The Columbia Plateau in the northwestern United States and the Deccan Traps in India were both built this way.
- Differential erosion: Where a hard, resistant rock layer caps softer rock beneath, the surrounding softer material erodes away while the capped block remains elevated, leaving an isolated tableland. Many smaller mesas and the tepuis of South America formed through this process.
Geographers also distinguish between intermontane plateaus (enclosed by mountains, like the Tibetan Plateau), piedmont plateaus (bordered by mountains on one side and a plain or sea on the other), and continental plateaus (rising abruptly from coastal plains or oceans, such as the plateaus of southern Africa).
Types and Major Examples Worldwide
Plateaus appear on every continent and vary enormously in size, height, and character. The most significant examples include:
- Tibetan Plateau (China): The highest and largest plateau on Earth, averaging over 4,500 m and covering about 2.5 million km².
- Deccan Plateau (India): A vast volcanic and ancient-rock plateau covering most of peninsular India, roughly 1.9 million km².
- Colorado Plateau (USA): Home to the Grand Canyon, Monument Valley, and many of America's national parks.
- Ethiopian Highlands / Abyssinian Plateau (Ethiopia): A rugged volcanic plateau often called the "Roof of Africa."
- Altiplano (Bolivia and Peru): A high Andean plateau at roughly 3,700 m containing Lake Titicaca, the highest navigable lake in the world.
- Columbia Plateau (USA): A volcanic plateau formed by basalt floods covering over 160,000 km².
- Tepuis (Venezuela): Isolated, flat-topped sandstone plateaus that inspired Arthur Conan Doyle's novel The Lost World.
Climate and Weather on Plateaus
Climate shapes the character of every plateau, and in turn the largest plateaus shape global climate. Because air cools with altitude, high plateaus experience markedly lower temperatures and more intense solar radiation than the lowlands at the same latitude. The Tibetan Plateau, for instance, has a mean annual temperature near 0 degrees Celsius despite lying at the same latitude as subtropical regions like northern India and Florida.
Plateaus also create rain-shadow effects: as moist air is forced up the windward escarpment it loses its moisture, leaving the interior far drier. This explains why many plateau interiors, from the Tibetan Plateau to the Iranian Plateau, are semi-arid or desert. The Tibetan Plateau is so massive that it deflects the jet stream and helps drive the Asian monsoon, influencing weather for billions of people.
Ecosystems and Natural Resources
Plateau ecosystems are remarkably varied, ranging from lush tropical forest on parts of the Deccan to barren alpine desert on the Tibetan Plateau, depending on elevation and rainfall. The isolation created by steep escarpments often produces high levels of endemism: the Ethiopian Highlands host the unique gelada baboon and Ethiopian wolf, while high Asian plateaus shelter the Tibetan antelope, wild yak, and snow leopard.
Plateaus are also rich in mineral wealth. The Deccan Plateau yields iron ore, manganese, coal, and diamonds, while plateaus elsewhere supply copper, tin, gold, and uranium. The glaciers and snowfields of the Tibetan Plateau, sometimes called the "Third Pole," feed rivers including the Yangtze, Yellow, Ganges, Indus, and Mekong, sustaining the water supply of nearly two billion people downstream.
Humans and Plateaus
Throughout history plateaus have served as natural fortresses and cultural heartlands. Their elevation made them defensible, while their level surfaces and reliable water made them suitable for farming and herding. The Inca civilization flourished on the Altiplano, and the Ethiopian and Anatolian plateaus have anchored powerful states for millennia. People who have lived on high plateaus for generations, such as Tibetans and Andean communities, have even evolved genetic adaptations that help them thrive in the thin, low-oxygen air. Today plateaus support agriculture, herding, mining, hydroelectric power, and a growing tourism industry centered on their spectacular scenery.
Key Facts
- Definition: An elevated area of flat or gently rolling land bounded by steep escarpments on at least one side.
- Largest plateau: The Tibetan Plateau, about 2.5 million km² and over 4,500 m average elevation.
- Main formation processes: Tectonic uplift, volcanic lava flows, and differential erosion.
- Notable canyon: The Grand Canyon, cut by the Colorado River into the Colorado Plateau.
- Highest navigable lake: Lake Titicaca, on the Altiplano at roughly 3,800 m.
- Dramatic escarpment: The Drakensberg in South Africa, rising about 3,000 m above the coastal plain.
- Water tower: The Tibetan Plateau feeds rivers serving nearly two billion people.
Frequently Asked Questions
What is the difference between a plateau and a mountain?
A mountain rises to a peak or sharp ridge, while a plateau has a broad, flat or gently rolling top. Both stand high above their surroundings, but a plateau's defining feature is its level summit bounded by steep edges, whereas a mountain narrows toward its summit.
What is the largest plateau in the world?
The Tibetan Plateau is the largest and highest plateau on Earth, covering about 2.5 million square kilometers and averaging more than 4,500 meters in elevation. It is often called the "Roof of the World."
How is a plateau formed?
Plateaus form mainly in three ways: by tectonic uplift when colliding plates push the crust upward, by repeated volcanic lava flows that build flat layered surfaces, and by erosion that strips away softer surrounding rock and leaves a resistant block elevated as a tableland.
Why are plateaus important to humans?
Plateaus provide fertile farmland, grazing land, and mineral resources, and their glaciers and snowfields feed major rivers that supply water to billions of people. Historically their height made them defensible homelands for civilizations such as the Inca.