Earthquake Magnitudes
Different ways to gauge the size of earthquakes.
Earthquake Magnitudes
Measuring the big ones with the Richter scale and its relatives.
Measuring the big ones with the Richter scale and its relatives.
Earthquake Intensities
Intensity scales measure how bad a quake is, on a scale from I to XII.
Intensity scales measure how bad a quake is, on a scale from I to XII.
Strange Seismometers
A seismometer can be as simple as a rock just standing there or as unexpected as soup cans on the grocer's shelves.
A seismometer can be as simple as a rock just standing there or as unexpected as soup cans on the grocer's shelves.
Did You Feel It?
Gauging earthquakes on the Web with the Community Internet Intensity scale.
Gauging earthquakes on the Web with the Community Internet Intensity scale.
Earthquake Intensity Scales Compared
Mercalli, Rossi-Forel, Omori, and European Macroseismic scales put side by side.
Mercalli, Rossi-Forel, Omori, and European Macroseismic scales put side by side.
Modified Mercalli Intensity Scale
How U.S. earthquakes are ranked from I to XII.
How U.S. earthquakes are ranked from I to XII.
European Macroseismic Intensity Scale
A summary of the most modern earthquake intensity scale, used in European countries.
A summary of the most modern earthquake intensity scale, used in European countries.
MSK Earthquake Intensity Scale
The predecessor of the EMS scale was widely used in Europe and India after 1964.
The predecessor of the EMS scale was widely used in Europe and India after 1964.
Japanese Intensity Scale of 1996
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 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.
Japanese Intensity Scale of 1949
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 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 Omori Earthquake Intensity Scale
The original Japanese seismic intensity standard, based on typical Japanese structures.
The original Japanese seismic intensity standard, based on typical Japanese structures.