ICa5 ICS LIG IIICCIISILY to powers of 10. A quake which registers 6.0 is 10 times more severe than one which measures 5.0; correspondingly, one which measures 7.0 releases 10 times more energy than a 6.0, or 100 times more than a 5.0. So a famous one such as the quake in San Francisco in 1906 (8.6) or Alaska in 1964 (8.3) is actually over a thousand times more devastating than a quake with a modest 5.0 reading on the scale