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QuakeFYI

Earthquake Magnitude Comparison

Compare two earthquake magnitudes side-by-side. See the energy ratio, amplitude ratio, and TNT equivalents instantly.

Calculator
Presets

비교 결과

Energy Ratio
10^(1.5 × )
Amplitude Ratio
10^
Magnitude Diff
units apart
Earthquake A — TNT
Earthquake B — TNT

Relative Energy Scale

How to Use

  1. 1
    Set Magnitude A

    Use the slider or type a value between 1.0 and 10.0 to set the first earthquake magnitude.

  2. 2
    Set Magnitude B

    Use the second slider to set the second earthquake magnitude for comparison.

  3. 3
    Compare the results

    View the energy ratio, amplitude ratio, and TNT equivalents for both magnitudes side-by-side. Use presets for famous historical earthquake pairs.

About

Earthquake magnitude is measured on a logarithmic scale, meaning each whole-number increase represents a tenfold increase in seismic wave amplitude and approximately 31.6 times more energy released. This relationship is described by the Gutenberg-Richter energy-magnitude formula: log10(E) = 1.5M + 4.8, where E is energy in joules and M is the moment magnitude.

The moment magnitude scale (Mw) replaced the original Richter scale for most purposes. Unlike the Richter local magnitude (ML), moment magnitude does not saturate at high values, making it the preferred scale for large earthquakes. Two earthquakes that differ by just 2 magnitude units release roughly 1,000 times different amounts of energy.

Key facts: each 1.0 increase = 31.6x more energy and 10x larger wave amplitude. Each 2.0 increase = ~1,000x more energy. The largest recorded earthquake was the 1960 Chile earthquake at M9.5. The 2011 Tohoku M9.1 released energy equivalent to about 600 million tons of TNT.

FAQ

How much more energy does one magnitude unit represent?
Each whole-number increase in earthquake magnitude corresponds to approximately 31.6 times (10^1.5) more energy released. Two magnitude units represent about 1,000 times more energy.
What is the difference between amplitude and energy ratios?
The amplitude ratio is 10 raised to the magnitude difference. The energy ratio is much larger because energy scales with the 1.5 power: 10^(1.5 times the difference). A 1.0 magnitude difference means 10x amplitude but 31.6x energy.
What is TNT equivalent?
TNT equivalent expresses earthquake energy in terms of the explosive yield of TNT. A M5 earthquake releases energy equivalent to about 500 tons of TNT, while a M9 releases about 480 megatons.
Why was the Richter scale replaced?
The Richter scale saturates above M7, meaning it underestimates the energy of the largest earthquakes. The moment magnitude scale (Mw) is based on seismic moment and works accurately at all magnitudes.
What is the strongest earthquake ever recorded?
The strongest recorded earthquake was the 1960 Valdivia earthquake in Chile at M9.5. It released approximately 1.8 exajoules of energy.