the richter scale is logarithmic, meaning that each increase of 1 on
the richter scale corresponds to an increase of 10 in the amplitude of
the seismic waves created by an earthquake.  An earthquake that
measures 8 on the Richter scale has how many times more ground-shaking
than a quake that measures 6 on the richter scale?

Howdy daisy001-ga,

The Argonne National Laboratory Division of Educational Programs, hosts
"NEWTON," which is an "electronic community for Science, Math, and Computer
Science K-12 Educators."  They have a brief, but nice, explanation of the
Richter scale.
http://www.newton.dep.anl.gov/askasci/gen99/gen99039.htm

"For example, a magnitude 6 earthquake will produce ten times the ground
motion that a magntidue 5 earthquake will produce, but ten times less
ground motion than a magnitude 7 earthquake. The amount of energy released
by an earthquake varies by a factor of 30 for each unit increase in the
magnitude--a magnitude 6 earthquake produces 30 times the energy of a
magnitude 5 earthquake and 30 times less energy than a magnitude 7
earthquake.  Incidentally, a magnitude 5 earthquake produces about as much
energy as the nuclear bombs dropped on Japan during World War II."

In your example, a magnitude 8 earthquake would produce 100 times (10 times
10) the ground motion of a magnitude 6 earthquake and 900 times (30 times
30) the amount of energy would be released by the magnitude 8 earthquake
than a magnitude 6 earthquake.

If you need any clarification, please feel free to ask.


Search strategy:

Google search on: "Richter scale" earthquake
://www.google.com/search?q=%22Richter+scale%22+earthquake

Looking Forward, denco-ga - Google Answers Researcher