Trinity on Istanbul

25 kt fission weapon · Turkey · Population 15,460,000 · Density 2,900/km²

About this scenario

This page calculates what would happen if the Trinity (USA, 1945) detonated over Istanbul (Turkey). First nuclear test.

The largest city in Turkey and Europe's largest metropolitan area, straddling the Bosporus strait. With an urban-core density of about 2,900 people per km², even a relatively small detonation over the city center would affect a large population.

The Trinity delivers 25 kt of explosive yield — 2× 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 (Trinity over Istanbul)

Effect zoneRadiusEst. affected
Fireball (vaporization, 100% fatal)0.53 km~2,516
Severe blast (20 PSI, ~98% fatal)1.39 km~14,842
Moderate blast (5 PSI, ~50% fatal)2.98 km~31,586
Light blast (1 PSI, glass injuries)8.48 km~28,682
3rd-degree thermal burns2.51 km
2nd-degree thermal burns4.49 km

Estimated total fatalities: ~48,944 · Estimated total affected (inside 1 PSI light-blast radius): ~654,521.

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 Trinity struck ground level rather than detonating optimally above Istanbul.

Effect zoneRadius (surface burst)
Fireball0.42 km
Severe blast (20 PSI)0.77 km
Moderate blast (5 PSI)1.64 km
Light blast (1 PSI)4.66 km
3rd-degree thermal burns1.50 km
Lethal fallout zone~43.5 km

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

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Trinity on other cities

Other weapons on Istanbul

FAQ

What would happen if the Trinity detonated over Istanbul?

In an air burst over Istanbul, the Trinity (25 kt) would produce a fireball about 0.53 km in radius. The 5 PSI moderate-blast zone — where most residential buildings collapse — would extend to 2.98 km. Light blast damage and shattered windows would reach 8.48 km. Given Istanbul's urban density (~2,900/km²), this scenario yields an estimated 48,944 immediate fatalities and about 28,682 additional injured.

How many people would die in Istanbul from a Trinity strike?

An air burst of the Trinity over Istanbul could cause an estimated 48,944 immediate fatalities and 28,682 additional injuries. The fireball alone (radius 0.53 km) would kill approximately 2,516 people; the severe-blast zone (20 PSI, radius 1.39 km) would add 14,842; the moderate-blast zone (5 PSI, radius 2.98 km) would add 31,586 more. Real numbers depend heavily on time of day, sheltering, weather, and altitude of detonation.

What is the blast radius of the Trinity on Istanbul?

For an air burst over Istanbul: fireball 0.53 km, severe blast (20 PSI) 1.39 km, moderate blast (5 PSI) 2.98 km, light blast (1 PSI) 8.48 km. Thermal radiation causes 3rd-degree burns out to 2.51 km. A surface burst would shrink the blast radii by roughly 40 percent but generate massive radioactive fallout extending ~43 km from ground zero.

Is the Trinity bigger than the bomb that hit Hiroshima?

The Hiroshima bomb (Little Boy) had a yield of about 15 kilotons. The Trinity at 25 kt is 2× more powerful than the Hiroshima bomb.

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