DOUBLE-COUPLE MOMENT TENSORS FOR THE 1976 GAZLI AFTERSHOCK EARTHQUAKESEQUENCE

An extension of the relative amplitude method is used to obtain the 'b est-fit' orientation of a presumed double-couple source for 38 earthqu akes 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). Th e data used are digitised medium-aperture array observations of the ph ases P, pP and sP. It is found that all of the solutions are very well constrained in dip and slip angle to be 45 degrees dipping reverse fa ults. The strike, while comparatively less well constrained by the dat a than the dip and slip angle, is found to be generally northwest-sout heast in 34 of the earthquakes analysed; this is consistent with solut ions computed by other workers.