M2.5 : 2.71 h
M3.0 : 11.0 h
M3.5 : 1.87 d
M4.0 : 7.59 d
M4.5 : 30.9 d
M5.0 : 125 d
M5.5 : 1.40 y
M6.0 : 5.68 y
M6.5 : 23.1 y
M7.0 : 93.9 y
M7.5 : 382 y
M8.0 : 1550 y
Based on 970 events. Largest M6.9
n = Events per year with magnitude >= M
M <= 8.0
log10(n) = 6.56 - 1.218*M