Intensity -a measure of the degree of earthquake shaking at a given locale based on the amount of damage
Modified Mercalli Intensity Scale
Magnitude - measurement made from data calculations shown in seismographs
Richter Scale
A way to measure the size of an earthquake by using the largest amplitude seismic wave recorded on a seismogram
A logarithmic scale
Not accurate for large quakes
Rating of 2.0 is not felt by humans
An 8.9 releases the same amount of energy as 1 billion tons of TNT
Moment Magnitude (Mw)
More precise measure derived from the amount of displacement occurring along a fault zone, the area of the rupture surface, and the shear strength of the faulted rock
The shear strength is a measure of the strain energy a rock can store before it slips and releases the energy as an earthquake
