STRIKE-SLIP EARTHQUAKES ON QUASI-VERTICAL TRANSCURRENT FAULTS - INFERENCES FOR GENERAL SCALING RELATIONS

The recent occurrence of several large strike-slip earthquakes provides the opportunity to review and complement available data on the scaling of seismic moment (M(O)) with length of rupture (L) for large earthquakes, depending on their tectonic setting and mechanism. For strike-slip earthquakes on quasi-vertical transcurrent faults, the M(O) versus L relation has a significant change of slope around M(O) approximately (O.6-0.8)*10(20) N-m, and for larger earthquakes, M(O) scales linearly with L. This is compatible with models where slip is controlled by the width of the fault. Also, it appears to be easier to categorize large earthquakes by their mechanism (strike-slip on vertical transcurrent fault, versus pure thrust/normal) than their tectonic setting (interplate/intraplate).