How much more energy is released in an earthquake whose value is 4 on Richter Scale than in an earthquake whose value is 3 on Richter Scale?

On the Richter scale each one-unit rise corresponds to about a tenfold increase, so a four releases roughly ten times a three.

Twice is far too small a step for a one-unit rise on this scale.

A ten percent increase badly understates the jump, which is manyfold.

A fifty percent increase also greatly understates the true difference.

Each whole-number step on the Richter scale means roughly a tenfold rise in measured ground motion.

The scale is logarithmic, so small number changes reflect very large physical differences.