Different ways to gauge the size of earthquakes.
Measuring the big ones with the Richter scale and its relatives.
Intensity scales measure how bad a quake is, on a scale from I to XII.
A seismometer can be as simple as a rock just standing there or as unexpected as soup cans on the grocer's shelves.
Gauging earthquakes on the Web with the Community Internet Intensity scale.
Mercalli, Rossi-Forel, Omori, and European Macroseismic scales put side by side.
How U.S. earthquakes are ranked from I to XII.
A summary of the most modern earthquake intensity scale, used in European countries.
The predecessor of the EMS scale was widely used in Europe and India after 1964.
The modern version of the Japanese scale is based on instrumentally recorded accelerations and changes the traditional seven categories to ten. This page is from the Japanese Meteorological Agency.
The Japanese Meteorological Agency (JMA) 1949 Seismic Intensity Scale was the successor to the Omori scale, used until 1996. This page is from the Japanese government.
The original Japanese seismic intensity standard, based on typical Japanese structures.
