Earthquake Energy Calculator
Calculate the energy (J) an earthquake releases from its magnitude. Convert it to TNT and Hiroshima bombs to grasp the true scale.
Input
Enter a magnitude to estimate the energy an earthquake releases using the Gutenberg-Richter relation log₁₀E = 4.8 + 1.5M (E in joules). Each whole step up in magnitude releases about 32 times more energy.
M
Result
Earthquake energy (estimate)
2.0 × 10^15J
Magnitude
M 7.0
Equivalent TNT
about 476.9 kilotons
Hiroshima bombs
about 32 bombs
Estimated using 1 ton of TNT = 4.184×10⁹ J and one Hiroshima-type bomb ≈ 6.3×10¹³ J. Actual damage depends heavily on focal depth, ground conditions, and distance from the epicenter.
Energy comparison by magnitude
| Magnitude | Energy (J) | TNT equivalent | Typical scale |
|---|---|---|---|
| M 3.0 | 2.0 × 10^9 | about 476.9 kg | Minor quake (sometimes felt) |
| M 5.0 | 2.0 × 10^12 | about 477 tons | Moderate quake (damage may begin) |
| M 6.0 | 6.3 × 10^13 | about 15.1 kilotons | Fairly strong quake |
| M 7.0 | 2.0 × 10^15 | about 476.9 kilotons | Major quake (e.g. Great Hanshin earthquake, M7.3) |
| M 8.0 | 6.3 × 10^16 | about 15.1 megatons | Great quake |
| M 9.0 | 2.0 × 10^18 | about 476.9 megatons | Megathrust quake (e.g. 2011 Tohoku earthquake, M9.0) |
How it works
- Uses the relation log10E = 4.8 + 1.5M (E in joules) to derive an earthquake's energy E from its magnitude M. This is the empirical formula established by Gutenberg and Richter.
- Under this formula, each one-step increase in magnitude multiplies the energy by about 32 (10 to the 1.5 power), and a two-step increase multiplies it by about 1000.
- The TNT conversion assumes 1 ton of TNT = 4.184×10^9 joules.
- The Hiroshima-bomb conversion treats that bomb's energy as about 6.3×10^13 joules (roughly 15 kilotons of TNT).
- The values shown are theoretical estimates derived from magnitude alone. Actual shaking and damage vary greatly with focal depth, distance from the source, and ground conditions.
- For decisions about earthquake scale or disaster preparedness, always check the latest information from official agencies such as the Japan Meteorological Agency. Use this tool's results as a rough guide only.
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Earthquake Energy Calculator