The expression **Richter magnitude scale** refers to a ways to assign a single number to quantify the energy contained in an earthquake. In this system invented by Charles Richter in 1935, one magnitude more is roughly equal to **a factor 32** more energy. That means an earthquake of magnitude 6.0 has 32 times more energy than an earthquake of magnitude 5.0. The below plot shows the amount of released energy in earthquakes with different magnitudes.

In the above image, the energy is expressed in Joule [left axis] and equivalent to ton TNT [right axis]. The black horizontal line shows the estimated energy of the first nuclear bomb dropped on Hiroshima. It roughly weights as a six Richter earthquake. Note that a large fraction of the energy of earthquakes is absorbed in the deep layers of the earth.