Earthquake magnitude and the logarithmic scale

The earthquake in Nepal was big, but there’s a discrepancy in just how big. The United States Geological Survey (USGS) measured the earthquake at 7.8 magnitude, whereas the China Earthquakes Network Center (CENC) measured it at 8.1. The three-tenths difference doesn’t seem like much, but the latter is actually an earthquake that exerts twice the energy of the former. Akshat Rathi and David Yanofsky for Quartz explain in a lesson of the logarithmic scale and earthquake magnitude.