The map above simulates a 300-kiloton nuclear airburst over Shanghai, China — 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 29 million people — the rings above are drawn to real scale over their homes.
The marker is on People's Square, the traditional centre of Puxi. The 1.9 km zone of total destruction covers the square, the Shanghai Museum, Nanjing Road's pedestrian street and the municipal government; the 4.7 km collapse ring reaches the Bund, Xintiandi, Jing'an Temple and, across the Huangpu, the skyscrapers of Lujiazui. Third-degree burns extend to about 7.5 km over the old French Concession, Hongkou, Xujiahui and the Pudong riverside; the 14.5 km ring of broken windows covers Hongqiao's edge, Wujiaochang, the Expo site and much of inner Pudong.
Shanghai's 29 million people make it one of the three largest urban areas on Earth, and the districts inside the inner ring road average over 20,000 people per square kilometre. The river is too narrow to absorb much blast, and the land is flat delta. For a weapon four times larger over China's capital, see the B83 over Beijing.
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