Mexico City sits at an average elevation of approximately 2,240 meters (7,350 feet) above sea level, making it one of the highest major urban centers globally. This altitude is the result of millions of years of continental-scale forces shaping the land. The city’s position is a direct consequence of its location on a massive elevated landform, which was created by the collision of Earth’s tectonic plates.
The Immediate Cause: The Mexican Plateau
Mexico City rests upon the expansive central highland known as the Mexican Plateau, or the Altiplano Mexicano. This massive landform extends roughly 1,130 kilometers from the United States border southward toward the center of the country. The plateau is bordered by the Sierra Madre Oriental to the east and the Sierra Madre Occidental to the west, which form its elevated boundaries.
The Mexican Plateau generally averages an elevation of 1,825 meters (5,988 feet) above sea level. This landform is divided into a lower northern section and a distinctly higher southern section, known as the Mesa Central. Mexico City is located on this southern, higher plateau, which averages around 2,000 meters (6,600 feet) in elevation.
The Deep Cause: Tectonic Activity and Continental Uplift
The existence of the vast, elevated Mexican Plateau is a direct consequence of tectonic activity beneath the North American continent. The fundamental process driving this uplift is the subduction of the Cocos oceanic plate beneath the North American continental plate. This collision occurs offshore along the Middle America Trench, where the Cocos Plate is slowly forced downward and eastward.
The Cocos Plate subducts at a shallow angle, creating flat-slab subduction beneath central Mexico. This geometry means the subducting plate travels horizontally beneath the continent, causing pressure and friction against the base of the North American Plate. The sustained pressure causes the continental crust above it to buckle, compress, and thicken over millions of years. This crustal thickening pushes the entire central region of Mexico upward, creating the high Mexican Plateau.
Local Geography: The Basin of Mexico and Volcanic Activity
While the tectonic uplift created the high plateau, the specific altitude and setting of the city are defined by the localized volcanic features of the Trans-Mexican Volcanic Belt (TMVB). This active, east-west oriented volcanic arc spans central-southern Mexico and rests on the southern edge of the uplifted North American Plate. The TMVB is a result of the same Cocos Plate subduction, as the descending oceanic crust releases water that triggers the melting of the mantle rock above it, forming magma that rises to the surface.
Mexico City is situated within the Basin of Mexico, which is a high-altitude valley formed and enclosed by the peaks of this volcanic belt. The basin is ringed by volcanic ranges, including the Sierra Nevada, which features the stratovolcanoes Popocatépetl and Iztaccíhuatl. These mountains, which can reach elevations over 5,000 meters, trap the air and water within the basin. The Basin of Mexico floor, where the city lies, is comprised of volcaniclastic material and filled-in ancient lakebeds, all resting at the height established by the underlying tectonic forces.