The map above simulates a 300-kiloton nuclear airburst over Mexico City, Mexico — roughly the size of a modern deployed warhead. The coloured rings show the estimated fireball, the zones of heavy, moderate and light blast damage, the reach of the thermal flash and the ionizing-radiation dose. Drag the marker or change the weapon in the full simulator to explore other scenarios.
The metropolitan area is home to about 22 million people — the rings above are drawn to real scale over their homes.
The marker is on the Zócalo. The 1.9 km zone of total destruction covers the cathedral, the National Palace, the Templo Mayor and the whole colonial centre; the 4.7 km collapse ring reaches the Alameda, Bellas Artes, Tlatelolco, La Merced and the Palacio Legislativo. Third-degree burns extend to about 7.5 km over the Roma and Condesa neighbourhoods, Chapultepec Park's eastern edge, Tepito and the airport's western boundary; the 14.5 km ring of broken windows covers Polanco, Coyoacán's northern streets, the Basilica of Guadalupe, Iztacalco and the Ciudad Universitaria's approach.
About 22 million people live in the Valley of Mexico, at 2,200 metres on the dried bed of Lake Texcoco; the thinner air slightly extends blast radii at a given yield. The city is flat inside the valley but ringed by volcanoes and hills, which would shade the settlements on their far slopes. Mexico was the driving force behind the Treaty of Tlatelolco, signed here in 1967, which made Latin America the first inhabited nuclear-weapon-free zone. See Nuclear arsenals.
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