Seismic moment and duration of recent large and great earthquakes

The methodology developed to verify the existence of a low frequency precursor to the great 1960 Chilean earthquake is applied to International Deployment of Accelerometers (IDA) station data in the 1–6 mHz band to determine the seismic moment and temporal centroid of 22 recent large and great earthquakes, including the 1989 Macquarie Ridge earthquake which has been reported to have a low‐frequency precursor (Imhlé et al., 1993). No clear evidence of precursors to any of these events is observed in the 1–6 mHz band. The seismic moment of large unilateral earthquakes of a given type of faulting is shown to be approximately proportional to the square of the duration. These data are observed to be well fit by this relation.