Each magnitude releases how much more energy than the previous magnitude?

Each magnitude releases how much more energy than the previous magnitude?

• A. 32
• B. 10
• C. 100
• D. 2

Answer: (A)

The key idea is that earthquake magnitudes are on a logarithmic scale with energy increasing very rapidly as magnitude goes up. Specifically, the energy released is proportional to 10 raised to the power of 1.5 times the magnitude (E ∝ 10^(1.5M)). When you increase the magnitude by one unit, the energy multiplies by 10^(1.5), which is about 31.6. In practice we round this to roughly 32. So each step up in magnitude releases about 32 times more energy than the previous one.

The key idea is that earthquake magnitudes are on a logarithmic scale with energy increasing very rapidly as magnitude goes up. Specifically, the energy released is proportional to 10 raised to the power of 1.5 times the magnitude (E ∝ 10^(1.5M)). When you increase the magnitude by one unit, the energy multiplies by 10^(1.5), which is about 31.6. In practice we round this to roughly 32. So each step up in magnitude releases about 32 times more energy than the previous one.