The South West seismic zone (also identified as SWSZ) is a major intraplate earthquake province located in the south west of Western Australia. [1] [2] [3]
It was known earlier as the Yandanooka–Cape Riche Lineament, [4] including the physiographic boundary known as the Meckering Line, and also the junction between Swanland[ clarification needed ] and Salinaland[ clarification needed ]. [5] [6]
The zone exists within an Archaean Shield structure called the Yilgarn Block. [7] The identified geological subdivisions within this Precambrian structure do not show an obvious relation to the seismicity. [8]
The zone represents a significant seismic hazard to Perth. [2] More than six thousand earthquakes have occurred in the SWSZ in the years 1968–2002. [8] Meckering, Cadoux and Burakin earthquakes originated in the SWSZ. More recent events have occurred to the south in Lake Muir in 2018 [9] [10] [11] [12] and Arthur River in 2022. [13]
The zone and the explanation of it, has been titled Perthquake in the Catalyst programme on the ABC in 2001. [14]
Temporal variation of the events in the region have been analysed over time. [15] [16] In the 2000s, monitoring and instrumentation was developed in the region. [17] [18]
The Australian southwest seismic zone (SWSZ) is a north-south trending belt of intra-plate earthquake activity that occurs in the southwest of Western Australia, bounded by 30.5°S to 32.5°S and 115.5°E to 118°E. This is one of the most seismically active areas in Australia, with nine earthquakes over magnitude 5.0 occurring between 1968 and 2002; the largest of these was the M6.8 Meckering earthquake in 1968. Since the SWSZ lies as close as ~150 km from the ~1.4 million population of the Perth region, it poses a distinct seismic hazard.