The South West Seismic Zone (also identified as SWSZ) is a major intraplate earthquake province located in the south west of Western Australia. It was known earlier as the Yandanooka – Cape Riche Lineament, corresponds to the physiographic boundary known as the Meckering Line, and also the junction between Swanland and Salinaland
The zone exists within an Archaean Shield structure called the Yilgarn Block. The identified geological subdivisions within this Precambrian structure do not show an obvious relation to the seismicity.
The zone represents a significant seismic hazard to Perth, Western Australia. More than six thousand earthquakes have occurred in the SWSZ in the years 1968 – 2002. Meckering, Cadoux and Burakin earthquakes originated in the SWSZ.
The zone and the explanation of it, has been titled Perthquake in the Catalyst programme on the ABC in 2001
Temporal variation of the events in the region have been analysed over time
Table of earthquakes
List of earthquakes of magnitude 4 or more in Southwestern Australia 1920–1961 (based in part on the records of Perth Observatory 1923–1959 and Mundaring Geophysical Observatory 1959–1980).