M2.5 : 21.8 h
M3.0 : 2.82 d
M3.5 : 8.79 d
M4.0 : 27.4 d
M4.5 : 85.2 d
M5.0 : 265 d
M5.5 : 2.26 y
M6.0 : 7.04 y
M6.5 : 21.9 y
M7.0 : 68.2 y
M7.5 : 212 y
M8.0 : 661 y
M8.5 : 2060 y
Based on 250,548 events. Largest M7.4
n = Events per year with magnitude >= M
M <= 8.5
log10(n) = 5.07 - 0.986*M