logarithmic

The moment magnitude scale is logarithmic — that is, each whole number of magnitude represents about a 30-fold increase in energy released.

The scale for brightness is reverse logarithmic, which means the brighter an object is, the lower its magnitude number.

The scale’s objective, base-10 logarithmic system caught on, and although it’s been superseded, people still attach his name to the scale.

But the February 6 earthquake was a 7.8—about four times bigger on the logarithmic scale of earthquake magnitudes.

Earthquakes are measured on a logarithmic scale, which means the difference between a 6.8 and a 7.8 is bigger than it sounds.