Earthquake Energy Calculator
Energy released by an earthquake in joules and tonnes of TNT, and how it compares with another magnitude.
Results
What this tool does
The scale is logarithmic, so the numbers hide how fast the energy climbs. The relationship used here, log E = 1.5M + 4.8, is the standard Gutenberg-Richter energy relation. The TNT comparison gives the scale a handle; it does not mean an earthquake behaves like an explosion.
Formula
log₁₀E = 1.5M + 4.8 (E in joules)
Variables
| Symbol | Meaning | Unit |
|---|---|---|
m1 | Magnitude | — |
m2 | Magnitude | — |
E | Energy | J |
TN | Energy | t TNT |
RA | Energy ratio | — |
AM | Ground motion ratio | — |
Worked example
- Magnitude6.5
- Magnitude5.5
- Energy354,813,389,234,000 J
- Energy84,802.435 t TNT
- Energy ratio31.623
- Ground motion ratio10.000
Limitations
- The default values are typical reference figures, not measurements of your situation. Replace them with your own data whenever you have it.
- The result is an estimate based only on the values you type. Real situations often include factors this calculator does not know about.
Frequently asked questions
Is a magnitude 7 ten times a magnitude 6, or more?
Both, depending on what you measure. The ground shakes about ten times as far, which is the amplitude ratio, but the energy released is about thirty-two times greater, because energy goes as the one-and-a-half power of magnitude. Two steps up the scale is a thousand times the energy, which is why the difference between a 6 and an 8 is the difference between damage and catastrophe.