This page shows a simulation of the 100000 kt nuclear bomb (100000 kt) detonated over San Francisco, CA, USA. The map displays the estimated fireball, the zones of heavy, moderate and light blast damage, thermal radiation and ionizing radiation. Click «What does that mean?» for a detailed legend, or run your own detonation on the main page.
100 megatons was the design yield of the Soviet AN602 — the Tsar Bomba — before its final stage was throttled back to 50 for the 1961 test. No weapon of this size was ever deployed: the bomb weighed 27 tonnes, no missile could lift it, and the arms race moved towards many smaller warheads instead. This scenario is therefore a physical ceiling, not a military one. The rings are enormous: a fireball about 12 km across, total destruction (20 psi) to roughly 13 km, collapse of houses (5 psi) to about 32 km, third-degree burns on exposed skin to about 75 km in clear weather, and broken windows (1 psi) out to about 100 km.
What that means in San Francisco
Centred on downtown San Francisco, the 13 km zone of total destruction covers the entire city, Oakland, Alameda, Daly City and Sausalito. The 32 km collapse ring takes in Berkeley, Richmond, San Mateo, Hayward, Walnut Creek's approaches, San Rafael and SFO — about 3.5 million people. Burns to 75 km reach San Jose, Palo Alto, Santa Rosa, Napa, Vallejo, Concord and Half Moon Bay; the 100 km ring of broken windows extends to Santa Cruz, Stockton's approaches, Sacramento's outer suburbs and Healdsburg. The hills of Marin and the East Bay would cast large shadows for the thermal flash. Compare with the 800-kiloton Topol scenario.