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Earthquake Magnitude Energy Calculator

Work out earthquake magnitude energy instantly with clear inputs, formula shown and shareable results.

About Earthquake Magnitude Energy Calculator

The Gutenberg-Richter relation gives log10(E) = 1.5M + 4.8 in joules, so each magnitude unit is about 31.6 times the energy and each 0.2 units roughly doubles it. A magnitude 6.5 releases 1.4e14 J, about 33 kilotonnes of TNT, and 31.6 times more energy than a 5.5 - though ground motion amplitude is only ten times larger.

Formulas

Gutenberg-Richter energy

log10(E) = 1.5 M + 4.8, E in joules

Energy ratio

ratio = 10^(1.5 x magnitude difference)

Worked example

With the default values below, Earthquake Magnitude Energy Calculator returns Radiated Seismic Energy of 3.54813 × 10¹⁴. Change any input above and every figure here is recalculated in your browser.

Inputs used

Moment magnitudeaccepts -2–10
6.5
Magnitude to compare againstaccepts -2–10
5.5

Results

Radiated Seismic Energy
3.54813 × 10¹⁴ J
TNT Equivalent
8.4802 × 10⁴ t
Energy Compared With The Other Magnitude
31.62 x
Ground Motion Amplitude Ratio
10.00 x

Step by step

  1. 1Values used
  2. 2Gutenberg-Richter energy
  3. 3Energy ratio
  4. 4Radiated Seismic Energy= 354,813,000,000,000.00000 J
  5. 5TNT Equivalent= 84,802.4000 t
  6. 6Energy Compared With The Other Magnitude= 31.62 x
  7. 7Ground Motion Amplitude Ratio= 10.00 x

Assumptions and limits

  • The result is derived only from the 2 inputs listed above. Anything not among them is not part of the calculation.
  • In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
  • Figures are rounded for display to 5 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

Why is energy 31.6 times per unit but amplitude only 10?

Because magnitude is a log10 amplitude scale, while energy scales as the 1.5 power of that - and 10^1.5 is 31.6.

Is all that energy destructive?

No. Radiated seismic energy is a small fraction of the total moment release; much goes into fracturing and heating the fault.

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