Double-couple moment tensors for the 1976 Gazli aftershock earthquake sequence

An extension of the relative amplitude method is used to obtain the 'best-fit' orientation of a presumed double-couple source for 38 earthquakes in the 1976 Gazli, Uzbekistan sequence. The body wave magnitudes of the earthquakes studied are between 4.0 m_b and 5.2 m_b (ISC). The data used are digitised medium-aperture array observations of the phases P, pP and sP. It is found that all of the solutions are very well constrained in dip and slip angle to be 45° dipping reverse faults. The strike, while comparatively less well constrained by the data than the dip and slip angle, is found to be generally northwest-southeast in 34 of the earthquakes analysed; this is consistent with solutions computed by other workers.