Is the Southwest Seismic Zone of Western Australia a fixed zone

The completeness magnitude for earthquakes in Western Australia in the decade prior to the Meckering earthquake is about M3, so the image below shows the progression of earthquakes M>=3 in the subsequent decades. North of Meckering (big purple star at the start of the gif), there is a trend of northeastward migration of seismicity away from Meckering. South of Meckering, the trend is not so obvious but there is still a general sense of migration of seismicity away from Meckering. Note also the fall off of seismicity in the direct vicinity of Meckering.

Decadal progression of Western Australian earthquakes. The white dots are pre-Meckering earthquake M>3 and the subsequent animation shows M>3 in 10 year periods since 14 October 1968.