M2.5 : 2.2 h
M3.0 : 9.1 h
M3.5 : 1.6 d
M4.0 : 6.6 d
M4.5 : 27.3 d
M5.0 : 114 d
M5.5 : 1.29 y
M6.0 : 5.4 y
M6.5 : 22.4 y
M7.0 : 93.3 y
M7.5 : 389 y
M8.0 : 1620 y
Based on 999 events. Largest M6.9
n = Events per year with magnitude >= M
M <= 8.0
log10(n) = 6.70 - 1.239*M