Trinity vs Gerboise Bleue
Nuclear weapon side-by-side comparison
Trinity
USA · 1945 · pure fission
25 kt
First nuclear test.
Gerboise Bleue
France · 1960 · pure fission
70 kt
First French nuclear test.
Verdict
The Gerboise Bleue is 2.8× more powerful than the Trinity by yield. Both weapons are described in detail below, with side-by-side blast and thermal radii, casualty estimates at a reference urban density, and historical context.
Blast & thermal effects (air burst)
| Effect zone | Trinity | Gerboise Bleue |
|---|---|---|
| Yield | 25 kt | 70 kt |
| Fireball radius | 0.53 km | 0.79 km |
| Severe blast (20 PSI) | 1.39 km | 1.96 km |
| Moderate blast (5 PSI) | 2.98 km | 4.19 km |
| Light blast (1 PSI) | 8.48 km | 11.91 km |
| 3rd-degree thermal burns | 2.51 km | 3.82 km |
| 2nd-degree thermal burns | 4.49 km | 6.85 km |
Casualty estimate (dense urban target)
Estimated immediate fatalities if each weapon air-bursts over a city center with a population density of about 8,000 per km² (representative of dense urban cores like Manhattan or central Paris):
Real casualties depend strongly on time of day, sheltering, weather, and altitude of detonation. See the methodology page for the underlying formulas.
Hiroshima reference
The Hiroshima bomb (Little Boy) had a yield of approximately 15 kilotons. The Trinity is 2× more powerful than the Hiroshima bomb. The Gerboise Bleue is 5× more powerful.
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FAQ
Is the Trinity bigger than the Gerboise Bleue?
No. The Gerboise Bleue (70 kt) is 2.8× more powerful than the Trinity (25 kt).
What is the blast radius of the Trinity compared to the Gerboise Bleue?
For an air burst, the Trinity produces a 5 PSI moderate-blast radius of 2.98 km, versus 4.19 km for the Gerboise Bleue. Severe blast (20 PSI): 1.39 km vs 1.96 km. 3rd-degree thermal burns: 2.51 km vs 3.82 km.
How many people would die from a Trinity compared to a Gerboise Bleue?
Detonated over a typical dense city center (8,000 people/km²), the Trinity would cause an estimated 135,018 immediate fatalities. The Gerboise Bleue would cause an estimated 266,390. Real numbers depend on time of day, sheltering, weather, and altitude of detonation.
How do the Trinity and Gerboise Bleue compare to the Hiroshima bomb?
The Trinity is 2× more powerful than the Hiroshima bomb (Little Boy, 15 kt). The Gerboise Bleue is 5× more powerful than the Hiroshima bomb.