Implications of Archambeau's earthquake source theory for slip on faults

Archambeau's source theory predicts a distinct peak in the displacement amplitude spectrum of body waves radiated into the far-field. If the assumption that earthquakes may alternatively be described by dislocation theory is valid, then this peak in the spectrum can occur only (1) if different parts of the fault, but on the same side of the fault, slip in opposite directions or (2) if the fault slips back after exceeding the maximum displacement. Data at the present time do not provide strong evidence for a peak in the displacement spectrum. The peak in Archambeau's spectrum may be caused by the absence of frictional damping in his model.