Richter     TNT for Seismic    Example
Magnitude      Energy Yield    (approximate)

-1.5                6 ounces   Breaking a rock on a lab table
 1.0               30 pounds   Large Blast at a Construction Site
 1.5              320 pounds
 2.0                1 ton      Large Quarry or Mine Blast
 2.5              4.6 tons
 3.0               29 tons
 3.5               73 tons   
 4.0            1,000 tons     Small Nuclear Weapon
 4.5            5,100 tons     Average Tornado (total energy)
 5.0           32,000 tons
 5.5           80,000 tons     Little Skull Mtn., NV Quake, 1992
 6.0        1 million tons     Double Spring Flat, NV Quake, 1994
 6.5        5 million tons     Northridge, CA Quake, 1994
 7.0       32 million tons     Hyogo-Ken Nanbu, Japan Quake, 1995; Largest Thermonuclear Weapon
 7.5      160 million tons     Landers, CA Quake, 1992
 8.0        1 billion tons     San Francisco, CA Quake, 1906
 8.5        5 billion tons     Anchorage, AK Quake, 1964
 9.0       32 billion tons     Chilean Quake, 1960
10.0       1 trillion tons     (San-Andreas type fault circling Earth)
12.0     160 trillion tons     (Fault Earth in half through center,
                               OR Earth's daily receipt of solar energy)