Earthquake Severity

Richter         Earthquake
Magnitudes      Effects

Less than 3.5   Generally not felt, but recorded.

3.5-5.4         Often felt, but only minor damage.

5.5-6.0         Slight damage to buildings.

6.1-6.9         Can be destructive In areas where people live.

7.0-7.9         Major earthquake. Causes serious damage.

8 or greater    Great earthquake. Total destruction to nearby communities.

Richter          TNT Energy    Example
Magnitude        Equivalent    (approximate)

1.0                 6 ounces   Small Blast at a Construction Site
1.5                 2 pounds
2.0                13 pounds
2.5                63 pounds
3.0               397 pounds
3.5             1,000 pounds
4.0                 6 tons
4.5                32 tons     Average Tornado
5.0               199 tons
5.5               500 tons     Little Skull Mtn., NV Quake, 1992
6.0             6,270 tons     Double Spring Flat, NV Quake, 1994
6.5            31,550 tons     Northridge, CA Quake, 1994
7.0           199,000 tons     Hyogo-Ken Nanbu, Japan Quake, 1995
7.5         1,000,000 tons     Landers, CA Quake, 1992
8.0         6,270,000 tons     San Francisco, CA Quake, 1906
8.5        31,550,000 tons     Anchorage, AK Quake, 1964
9.0       199,999,000 tons     Chilean Quake, 1960
10.0      6.3 billion tons     (San-Andreas type fault circling Earth)
12.0       1 trillion tons     (Fault Earth in half through center,
                               OR Earth's daily receipt of solar energy)