M2.5 : 11.5 h
M3.0 : 1.51 d
M3.5 : 4.76 d
M4.0 : 15.0 d
M4.5 : 47.3 d
M5.0 : 149 d
M5.5 : 1.29 y
M6.0 : 4.05 y
M6.5 : 12.8 y
M7.0 : 40.3 y
M7.5 : 127 y
M8.0 : 400 y
M8.5 : 1260 y
Based on 231,446 events. Largest M7.9
n = Events per year with magnitude >= M
M <= 8.5
log10(n) = 5.37 - 0.997*M