A scale devised by US geologist Charles F. Richter (1900–1985) used
to measure the magnitudes of earthquakes
in terms of the amplitude and frequency of the surface
waves. The scale runs from 0 to 10, and is logarithmic – each point on the scale increases by a factor of ten. About one quake a year registers
|The Richter scale, being of empirical numerical origin,
does not directly reflect any subjective scale of earthquake intensities.
In this table, an attempt is made to correlate a subjective scale
with corresponding Richter magnitudes, imagining the observer to be
near the epicenter of the earthquake.
Another scale used to measure earthquakes is the modified Mercalli
scale, which is a scale of 12 points used for measuring earthquaker
intensity. Named after the Italian seismologist Giuseppe Mercalli
(1850–1914), it is based on damage done at any point and so varies
from place to place.
AND PLANETARY SCIENCE