March 18, 2013 – Earthquake (EQ) Energy Release Comparison: The graph above depicts the relative energy released by earthquakes of various magnitudes. The Richter Magnitude (M) Earthquake Scale is exponential. Something is said to increase exponentially if its rate of change is not a straight line, but is a curve that continually becomes steeper.
The Richter Magnitude Scale is really comparing waves on a seismograph. Therefore, an 8M EQ is 10 times stronger than a 7M EQ. However, a 9M is 100 times stronger (10 times 10) than a 7M EQ. This relationship is graphed above. Clearly, the 9M+ mega-quakes in Sumatra in 2006 and Japan in 2011 reflect tremendous power.
The waves on a seismograph do not reflect the strength (energy) of EQ’s. Since it is really the energy or strength that knocks down buildings, and produces enormous tsunamis, this is really the more important measure. Using this scale an 8M EQ is 32 times stronger than a 7M EQ. However, a 9M EQ is about 1,000 times stronger (32 times 32) than a 7M EQ. This means that it would take 1,000 EQ’s of magnitude 7 to equal the energy released by one magnitude 9M event.
The Master of Disaster