Earthquake Energy as a Function of Magnitude
Magnitude Energy Equivalent Weight of TNT* Energy in joules
(1 J = 1 newton meter)
Notes
-3.0 0.001 ounces 2 J 1.5 foot pounds (18 inch pounds)
-2.0 0.032 ounces 63.1 J 47 foot pounds
-1.0 1.0 ounces 2E+03 J 1,500 foot pounds
0.0 32 ounces 63.1E+03 J  
1.0 63 pounds 2E+06 J  
2.0 1 ton 63.1E+06 J Only felt nearby.
3.0 32 tons 2E+9 J  
4.0 1 kton 63.1E+9 J Often felt up to 10's of miles away.
5.0 32 ktons 2E+12 J  
6.0 1,000 ktons 63.1E+12 J  
6.9 22,700 ktons 1.41E+15 J 1995 Kobe, Japan, Earthquake
7.0 32,000 ktons 2E+15 J  
8.0 1 Mtons 63.1E+15 J  
9.0 32,000 Mtons 2E+18 J  
9.2 64,000 Mtons 3.98E+18 J 1964 Alaska Earthquake - Second largest instrumentally recorded earthquake
9.5 180,000 Mtons 11.2E+18 J 1960 Chile - Largest instrumentally recorded earthquake