Back
Richter's Scale
Charles
Francis Richter 
Charles
Francis Richter was born in the Ohio countryside
on April 26, 1900. He and his mother migrated to
southern California when he was a teenager,
where he got enrolled in a college. Latter he
moved to Palo Alto to study physics at Stanford
University. After graduation Richter returned
and started working at the Seismological
Laboratory of the Carnegie Institution of
Washington. In 1928, he got his doctorate in
theoretical physics at the California Institute
of Technology.
The
Richter magnitude scale was developed by him in
1935 while he was at the California Institute of
Technology as a mathematical device to compare
the size of earthquakes. In Richter's Scale the
magnitude of an earthquake is determined from
the logarithm of the amplitude of waves recorded
by seismographs. Adjustments are included for
the variation in the distance between the
various seismographs and the epicenter of the
earthquakes. On the Richter Scale, magnitude is
expressed in whole numbers and decimal
fractions. For example, a magnitude 5.3 might be
computed for a moderate earthquake, and a strong
earthquake might be rated as magnitude 6.3.
Because of the logarithmic basis of the scale,
each whole number increase in magnitude
represents a tenfold increase in measured
amplitude; as an estimate of energy, each whole
number step in the magnitude scale corresponds
to the release of about 31 times more energy
than the amount associated with the preceding
whole number value.
The Richter
magnitude scale can be used to describe
earthquakes so small that they are expressed in
negative numbers. The scale also has no upper
limit, so it can describe earthquakes of
unimaginable and (so far) unexperienced
intensity, such as magnitude 10.0 and beyond.
Back
