West Australians may feel aftershocks from a 5.6 magnitude earthquake for days, a Geoscience Australia senior seismologist says.
The Joint Australian Tsunami Warning Centre detected the earthquake, reported as being centred between Kojonup and Walpole, just before 1pm local time on Sunday.
Professor Phil Cummins told AAP that he expected aftershocks "of decreasing magnitude and size" to continue for some time.
While residents in Perth have reported feeling the earthquake more than 400 kilometres away, Professor Cummins does not expect noticeable aftershocks there.
But residents in Walpole, nearer to the quake, may feel aftershocks for days.
Those in the immediate vicinity of the quake could even feel the aftershocks for weeks.
"It is quite a rare event and especially to have it occurred in this place. On the south coast earthquakes are more rare."
The agency has no recorded earthquake above 5.0 magnitude in the immediate area of Sunday's event, Professor Cummins said.
"It has occurred because of the build-up of the stress in the Australian crust (in the tectonic plates). Strong forces get transmitted across the Australian point and when it exceeds ... there's an earthquake," he said.
Walpole Visitors Centre volunteer Colin Steele told AAP it felt "like a big truck passing very close by" for about five to eight seconds.
"It was nothing too startling. You had to be in a building (to feel it). Now I can say I stood in an earthquake," he said.
Walpole IGA co-partner James Griffiths said the building shook "quite substantially" but only one bottle of wine in the liquor section landed on the floor.
There is no tsunami threat to the Australian mainland, island or territories, the centre says.