Johannesburg city centre sits 0 m from Johannesburg, the most plausible strategic target in the area (low targeting confidence). Modelled strike: 100 kt airburst.
Estimated survival chance at city centre: 0% · Estimated metro fatalities: 112.1K, injuries: 134.9K
What a strike on Johannesburg would mean
A 100 kt detonation produces a fireball 416 m across in radius. Reinforced concrete fails out to 1.6 km (20 psi). Most residential buildings collapse within 3.2 km (5 psi), and windows shatter dangerously out to 7.2 km (1 psi). Anyone in line of sight within 4.4 km suffers third-degree burns from the thermal pulse.
An airburst maximises blast damage but produces minimal local fallout, so for Johannesburg the dominant risks are blast and thermal effects rather than radiation.
Most plausible targets near Johannesburg
| Target | Type | Distance | Assumed yield | Confidence |
|---|---|---|---|---|
| Johannesburg | city | 0 km | 100 kt | low |
| Nairobi | city | 2925 km | 100 kt | low |
| Lagos | city | 4508 km | 100 kt | low |
| Diego Garcia | military | 5135 km | 300 kt | medium |
| Riyadh | government | 6005 km | 150 kt | medium |
Key blast radii (100 kt airburst)
| Effect | Radius | What happens |
|---|---|---|
| Fireball | 416 m | Complete vaporisation |
| 20 psi blast | 1.6 km | Hardened structures destroyed, ~100% fatalities |
| 5 psi blast | 3.2 km | Most buildings collapse, widespread fatalities |
| 3rd-degree burns | 4.4 km | Full-thickness burns to exposed skin |
| 500 rem radiation | 1.9 km | Lethal dose without medical care |
| 1 psi blast | 7.2 km | Window breakage, light damage, glass injuries |
How Johannesburg can prepare
With a population density of 2,900 people/km², Johannesburg's outcome would hinge on the first hour. The guidance is identical everywhere: get inside, stay inside, stay tuned. A basement or the core of a large concrete building cuts fallout exposure by a factor of 10 or more, and radiation decays fast — dose rates fall ~90% within the first 7 hours and ~99% within two days.
Check your exact address in Johannesburg →