More than 20 aftershocks have been recorded with more expected today after a 5.5 magnitude earthquake struck Western Australia's south east.

Geoscience Australia said the tremor occurred at a depth of 16 kilometres at 5.40pm on Friday south east of Norseman, 720 kilometres east of Perth.

Senior seismologist Jonathan Bathgate said there were several aftershocks in the hours after the quake.

"A couple of magnitude threes and there are in excess of 20 earthquakes there that are much smaller than that we can't accurately locate, just because they're so small but they are occurring in that area," he said.

"We would expect some aftershock activity following an event of this size.

We probably would expect that to continue for a number of days and weeks but unfortunately we can't predict if there's any larger ones to come in that sequence."

There have been no reports of damage but the tremor was felt as far away as Perth.

"People in high-rise buildings in the Perth CBD in particular have reported having felt that, and that is commonly the case," Mr Bathgate said.

"People in high-rise tend to feel that shaking more strongly than people on the ground."

'Five large jolts' shook family home

Kylie Bailye said her family in Salmon Gums, south-west of the epicentre, felt the shaking for about 45 seconds.

"We had just had dinner. First of all there were loud earth noises, you could hear the rumble coming and then there was five fairly large jolts in succession," she said.

"Then the rumble continued and you could see small items start to move on the shelves."

"I went outside and all the birds had flown into the sky and they were all screeching."

It was felt even further south in the coastal town of Esperance, where resident Vicky Davidson said it was loud and strong.

"At 5:40pm the windows and the sliding doors started moving - and the floor - and Roy could hear the tiles on the roof and I raced outside and I could hear a very loud growling noise," she said.

"Then I rang a friend where I work and she said she was sitting in the office and her office desk started moving, so she raced out of the office to check residents at the local nursing home, hostel and they were all stunned, because the windows had all shuddered."

Ms Davidson said the shaking lasted about five seconds.

"It was very short, but very strong."

'Fortunate' quake struck uninhabited nature reserve

Mr Bathgate said it was not unusual to record earthquakes in this part of WA.

"This area of Australia is extremely seismically active, it's the most active area of the country ... and we record hundreds of earthquakes in and around this area every year," he said.

He said it was lucky the epicentre was beneath an uninhabited area in the Dundas Nature Reserve.

"This earthquake is comparable to the earthquake, in terms of magnitude, that occurred in Newcastle in 1989 at 5.4 so we all know the damage that that one caused," he said.

"This one being a little bit more distant from the populated centres is probably a fortunate occurrence in this case."

The Norseman area has experienced several minor quakes this year, including a 4.9-magnitude earthquake in May.