The seismicity of the Sydney Basin

Abstract

Minor earthquakes have been felt in the Sydney Basin since the foundation of the colony in 1788, but a systematic appraisal of the seismicity of the area was not possible until a network of seismograph stations was established there in 1958–1959. By means of this network, 181 tremors have been located in and around the Basin between 1959 and 1967, including the 1961 Robertson‐Bowral earthquake and 33 aftershocks. Many epicentres lie near the western boundary of the Sydney Basin, and some others appear to be associated with structures at the western edge of the inner Cumberland Basin. The epicentres of the Robertson‐Bowral sequence suggest a fault system trending to the northwest in that area. A number of events were located near the edge of the continental shelf, and it is possible that these may delineate the eastern edge of the Sydney Basin.