Richter Scale for Earthquakes

The Richter scale is logarithmic; that is, an increase of 1 magnitude unit represents a factor of ten times in amplitude.

  1. Recorded on local seismographs, but generally not felt
  2. Recorded on local seismographs, but generally not felt
  3. Often felt, no damage
  4. Often felt, no damage
  5. Felt widely, slight damage near epicentre
  6. Damage to poorly constructed buildings and other structures within 10 sq. km
  7. "Major" earthquake, causes serious damage up to ~100 km (recent Taiwan, Turkey, Kobe, Japan, and California earthquakes)
  8. "Great" earthquake, great destruction, loss of life over several 100 km (1906 San Francisco, 1949 Queen Charlotte Islands)
  9. Rare great earthquake, major damage over a large region over 1000 km (Chile 1960, Alaska 1964, and west coast of British Columbia, Washington, Oregon, 1700)