Earthquake Energy Calculator

How Earthquake Energy Is Calculated

The Richter scale and moment magnitude scale (Mw) are logarithmic — each whole number step represents about 31.6 times more energy released.

Energy-Magnitude Formula (Gutenberg-Richter): log₁₀(E) = 1.5 × M + 4.8

Where:

• E = energy in Joules
• M = moment magnitude (Mw)

Or rearranged: E = 10^(1.5M + 4.8)

Worked Example: Magnitude 7.0 earthquake:

• E = 10^(1.5 × 7.0 + 4.8) = 10^(10.5 + 4.8) = 10^15.3
• E ≈ 2.0 × 10¹⁵ Joules
• Equivalent to about 480 kilotons of TNT

Magnitude 8.0 earthquake (1 point higher):

• E = 10^(12.0 + 4.8) = 10^16.8 ≈ 6.3 × 10¹⁶ Joules
• That’s 31.6 times more energy than M7.0

Energy Scale Reference:

• M3.0: ~2 × 10⁹ J: felt locally, minor damage
• M5.0: ~2 × 10¹² J: moderate, can damage weak structures
• M7.0: ~2 × 10¹⁵ J: major, widespread damage
• M9.0: ~2 × 10¹⁸ J: great, catastrophic regional destruction
• M9.5 (Chile, 1960): largest recorded: ~3 × 10¹⁸ J

Key Insight: The logarithmic scale means M9.0 releases about 1,000 times more energy than M7.0, and about 31,600 times more than M6.0. This exponential scaling is why even a small increase on the Richter scale represents a dramatically more destructive event in practice — a M6.5 earthquake can cause minor damage, while a M7.5 can level entire cities.