M2.5 : 21.7 m
M3.0 : 1.07 h
M3.5 : 3.15 h
M4.0 : 9.29 h
M4.5 : 1.14 d
M5.0 : 3.37 d
M5.5 : 9.94 d
M6.0 : 29.3 d
M6.5 : 86.5 d
M7.0 : 255 d
M7.5 : 4.71 y
M8.0 : 31.7 y
M8.5 : 214 y
M9.0 : 1440 y
Based on 22,167 events. Largest M8.1
n = Events per year with magnitude >= M
M <= 7.0
log10(n) = 6.73 - 0.940*M
7.0 <= M <= 9.0log10(n) = 11.76 - 1.657*M