The largest plateaus in the world are the East Antarctic Plateau, the Brazilian Highlands, the Iranian Plateau, the Central Siberian Plateau, the Mongolian Plateau and the Tibetan Plateau — each covering well over two million square kilometres. Tibet is not the largest by area, but at an average elevation of roughly 4,500 metres it is by far the highest, which is why it dominates every discussion of plateau geography.
Ranking the world's plateaus is harder than it looks
Before any list is useful, one caveat has to be stated plainly: plateau areas are not measured the way country areas are. A nation has a legally defined border. A plateau has an edge that a geologist draws where the terrain stops being flat and high, and reasonable people draw that line in different places.
The Deccan Plateau is quoted at anywhere between 420,000 and 1.9 million square kilometres depending on whether you mean the basalt of the Deccan Traps, the Deccan proper between the Western and Eastern Ghats, or the whole peninsular upland south of the Satpura Range. The Iranian Plateau is sometimes confined to Iran and sometimes stretched east to include most of Afghanistan and western Pakistan, which roughly doubles the figure.
The figures below are therefore given as approximations, and the ordering should be read as a set of tiers rather than a leaderboard where positions three and four are meaningfully different.
Approximate areas of the major plateaus
- East Antarctic Plateau — several million square kilometres; the interior of the East Antarctic Ice Sheet, averaging around 3,000 m and rising above 4,000 m at Dome A
- Brazilian Highlands (Planalto Brasileiro) — roughly 4.5 million km², covering more than half of Brazil
- Iranian Plateau — roughly 3.7 million km² on the broad definition spanning Iran, Afghanistan and western Pakistan
- Central Siberian Plateau — roughly 3.5 million km², between the Yenisei and Lena rivers
- Mongolian Plateau — roughly 2.6 million km², including the Gobi and much of Inner Mongolia
- Tibetan Plateau — roughly 2.5 million km² at an average 4,500 m
- Deccan Plateau — roughly 1.9 million km² on the wide definition of peninsular India
- Patagonian Plateau — roughly 670,000 km² of arid steppe in southern Argentina
- Loess Plateau — roughly 640,000 km² of wind-deposited silt in northern China
- Colorado Plateau — roughly 337,000 km² across Utah, Arizona, Colorado and New Mexico
Why Tibet sits in a category of its own
Area is the wrong metric for Tibet. What makes the plateau exceptional is that an area comparable in size to Western Europe sits at an elevation most of the world only reaches at individual mountain summits. Lhasa, an ordinary provincial capital with an airport and traffic lights, stands at about 3,650 metres — higher than any point in the Alps outside the high peaks.
That elevation exists because of the continental collision that began when the Indian plate met Eurasia roughly 50 million years ago and never stopped. India is still driving north at a few centimetres a year. Rather than one plate sliding beneath the other cleanly, the crust beneath Tibet has thickened to around 70 kilometres — nearly double the global continental average — and the whole slab has been buoyed upward.
The consequences are not local. The plateau is large enough and high enough to act as an obstacle in the mid-troposphere, and its summer heating helps drive the South Asian monsoon that waters roughly a fifth of humanity. It also holds the largest volume of ice outside the polar regions, which is why it is often called the Third Pole. The Tibetan Plateau's geography is effectively a climate system as much as a landform.
Three different ways to build a plateau
Plateaus that look similar from the air often have nothing in common underneath. Three formation mechanisms account for almost all of them.
Tectonic uplift
The Tibetan and Iranian plateaus were pushed up by collision. The Colorado Plateau is a subtler case: a rigid block of crust that rose roughly two kilometres during and after the Laramide orogeny while somehow escaping the folding and faulting that wrecked the ranges around it. Its rock layers are still close to horizontal, which is precisely why the Grand Canyon reads like a textbook cross-section.
Volcanic flooding
Around 66 million years ago, enormous volumes of basaltic lava erupted across western India in a series of flows that stacked up more than two kilometres thick in places. The resulting Deccan Traps created a plateau by burial rather than by uplift. The Columbia Plateau in the American Northwest and the Ethiopian Highlands were built the same way.
Deposition and glaciation
China's Loess Plateau is a plateau made of dust. Silt blown off the deserts of Central Asia has accumulated over hundreds of thousands of years into deposits that reach 300 metres deep — soft, fertile, and so easily eroded that the Yellow River carries away a colossal sediment load. The East Antarctic Plateau, at the other extreme, is a plateau of ice: the bedrock beneath is uneven and in places below sea level, and the flat high surface belongs entirely to the ice sheet resting on top.
Plateaus compared with mountain ranges
Elevation alone does not make a plateau, and this is the distinction that trips people up most often. A mountain range like the Himalayas is defined by relief — the vertical distance between valley floors and summits. A plateau is defined by the absence of relief at altitude.
Stand in central Tibet and the horizon is broad, the ground rolls gently, and there is nothing to climb. Stand fifty kilometres south in the Himalayan front and the ground drops away thousands of metres into gorges. The two landforms are adjacent, made by the same collision, and behave completely differently.
The practical differences follow from that geometry:
- Travel — plateaus are crossable in most directions; ranges force traffic through a handful of passes
- Settlement — plateaus support dispersed grazing and, where water allows, extensive agriculture; mountains concentrate people into valleys
- Rivers — plateau rivers meander slowly across the surface until they reach the edge, then cut violently; mountain rivers are steep from the start
- Climate — a plateau creates one large cold, dry, high-radiation environment; a range creates sharp contrasts between windward and leeward sides
Similar confusion surrounds smaller flat-topped features. A mesa is a plateau remnant; a butte is a mesa reduced to a stub. They are the same landform at different stages of erosion, which is why the Colorado Plateau is full of all three.
The rivers that begin on high ground
Plateaus are disproportionately important as water sources, because high flat ground catches precipitation and holds glaciers without shedding them immediately.
The Tibetan Plateau alone gives rise to the Yangtze, the Yellow River, the Mekong, the Salween, the Brahmaputra, the Indus and the Ganges tributary system. That is the water supply for a large share of Asia originating in one upland. The Central Siberian Plateau feeds the Lena and the Lower Tunguska. The Brazilian Highlands supply the São Francisco and much of the Paraná.
Where a plateau river reaches the edge, it does something dramatic. Angel Falls drops from the Auyán-tepui in Venezuela's Guiana Highlands. The Blue Nile leaves the Ethiopian Highlands through a gorge that rivals the Grand Canyon in depth. The escarpment is where the plateau's stored potential energy is finally released.
What it means to live at altitude
Roughly seven million people live on the Tibetan Plateau, and several million more on the Andean Altiplano, which averages around 3,750 metres and holds Lake Titicaca and the Salar de Uyuni. These are among the highest permanently inhabited regions on Earth, and the populations there show genuine physiological adaptation.
Tibetan highlanders tend to breathe faster and carry higher levels of nitric oxide in the bloodstream without the elevated haemoglobin that visitors develop. Andean populations took a different route, with higher red blood cell concentrations. Two separate populations solved the same oxygen problem by different means — one of the clearest cases of recent human adaptation on record.
Agriculture at those elevations is correspondingly specialised. Barley, potatoes and quinoa dominate because they tolerate cold nights and a short growing season. Yaks on the Tibetan Plateau and llamas and alpacas on the Altiplano convert sparse grass into protein, wool and transport where cattle would fail outright.
Plateaus in a warming climate
High plateaus are warming faster than the global mean, and the consequences are concentrated rather than diffuse. Glacier retreat across the Tibetan Plateau threatens the dry-season flow of rivers that hundreds of millions of people depend on, and permafrost thaw is destabilising the ground beneath roads and rail lines.
The Loess Plateau presents the opposite kind of story — one of the largest deliberate landscape restorations ever attempted. Decades of terracing, tree planting and grazing restrictions have measurably reduced erosion and cut the Yellow River's sediment load, showing that plateau degradation is not always one-way.
If you want to keep testing how well you know the world's high ground and the ranges that border it, the world geography quiz works through exactly this kind of terrain, and our guide to the Deccan Plateau is a good next stop for anyone curious about how a continent-scale lava field turned into farmland.