Ivy Mike on Moscow

10.4 Mt thermonuclear weapon · Russia · Population 12,600,000 · Density 4,900/km²

About this scenario

This page calculates what would happen if the Ivy Mike (USA, 1952) detonated over Moscow (Russia). First hydrogen bomb test.

The capital of Russia and the largest city in Europe by population. With an urban-core density of about 4,900 people per km², even a relatively small detonation over the city center would affect a large population.

The Ivy Mike delivers 10.4 Mt of explosive yield — 693× more powerful than the Hiroshima bomb. The tables below show calculated effect radii for an air burst (optimized for blast spread) and a surface burst (which produces massive fallout).

Air-burst effects (Ivy Mike over Moscow)

Effect zoneRadiusEst. affected
Fireball (vaporization, 100% fatal)5.86 km~529,308
Severe blast (20 PSI, ~98% fatal)10.20 km~1,040,723
Moderate blast (5 PSI, ~50% fatal)21.80 km~2,856,869
Light blast (1 PSI, glass injuries)62.01 km~2,594,220
3rd-degree thermal burns29.72 km
2nd-degree thermal burns53.23 km

Estimated total fatalities: ~4,426,900 · Estimated total affected (inside 1 PSI light-blast radius): ~59,200,203.

Surface-burst effects (with fallout)

A surface burst trades blast spread for radioactive fallout — much smaller blast radii but a large lethal fallout plume drifting downwind. This is what would happen if the Ivy Mike struck ground level rather than detonating optimally above Moscow.

Effect zoneRadius (surface burst)
Fireball4.69 km
Severe blast (20 PSI)5.61 km
Moderate blast (5 PSI)11.99 km
Light blast (1 PSI)34.11 km
3rd-degree thermal burns17.83 km
Lethal fallout zone~485.3 km

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See the actual blast zones overlaid on a map of Moscow with population-density-based casualty estimates updated in real time as you move the detonation point.

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Ivy Mike on other cities

Other weapons on Moscow

FAQ

What would happen if the Ivy Mike detonated over Moscow?

In an air burst over Moscow, the Ivy Mike (10.4 Mt) would produce a fireball about 5.86 km in radius. The 5 PSI moderate-blast zone — where most residential buildings collapse — would extend to 21.80 km. Light blast damage and shattered windows would reach 62.01 km. Given Moscow's urban density (~4,900/km²), this scenario yields an estimated 4,426,900 immediate fatalities and about 2,594,220 additional injured.

How many people would die in Moscow from a Ivy Mike strike?

An air burst of the Ivy Mike over Moscow could cause an estimated 4,426,900 immediate fatalities and 2,594,220 additional injuries. The fireball alone (radius 5.86 km) would kill approximately 529,308 people; the severe-blast zone (20 PSI, radius 10.20 km) would add 1,040,723; the moderate-blast zone (5 PSI, radius 21.80 km) would add 2,856,869 more. Real numbers depend heavily on time of day, sheltering, weather, and altitude of detonation.

What is the blast radius of the Ivy Mike on Moscow?

For an air burst over Moscow: fireball 5.86 km, severe blast (20 PSI) 10.20 km, moderate blast (5 PSI) 21.80 km, light blast (1 PSI) 62.01 km. Thermal radiation causes 3rd-degree burns out to 29.72 km. A surface burst would shrink the blast radii by roughly 40 percent but generate massive radioactive fallout extending ~485 km from ground zero.

Is the Ivy Mike bigger than the bomb that hit Hiroshima?

The Hiroshima bomb (Little Boy) had a yield of about 15 kilotons. The Ivy Mike at 10.4 Mt is 693× more powerful than the Hiroshima bomb.

Casualty math uses Moscow's urban-core density and the scaling laws on the methodology page. See Ivy Mike weapon details, the Moscow scenario overview, or browse all scenarios.