Descriptor Richter Magnitudes Earthquake Effects Average Annually
Micro Less than 2.0 Microearthquakes, About 8,000 per day
not felt.
Very minor 2.0-2.9 Generally not felt, About 1,000 per day
but recorded.
Minor 3.0-3.9 Often felt, but 49,000 (estimated)
rarely causes damage.
Light 4.0-4.9 Noticeable shaking of indoor 6,200 (estimated)
items, rattling noises.
Significant damage unlikely.