Residents in a small Western Australian coastal town have described being jolted awake by a magnitude 5 earthquake in the early hours of this morning.

The United States Geological Survey says the earthquake's epicentre was 370 kilometres north-north-east of Carnarvon at a depth of 9.8 kilometres and measured the magnitude at 5.1.

Geoscience Australia measured the depth of the quake at 15 kilometres.

Geoscience Australia described the quake as moderate but said it was the largest earthquake recorded in the state this year.

Senior duty seismologist Dan Jaksa says there are no reports of damage.

"We've had sporadic reports coming in from people that have felt the earthquake, only about 10 [reports] at the moment," he said.

"We expect more during the day as people find out about the earthquake and then report it on our Geoscience Australia website."

In the small town of Onslow, on the coast north of Exmouth, residents said they did not realise it was an earthquake that jolted them awake in the early hours of this morning.

Michelle Paley says she and her flatmate were both woken when their house started shaking but they had no idea was an earthquake.

"The bed just shook quite hard. My bed's up against the wall, so it shook the bed enough to wake me up," she said.

"It was just that sudden jolt, enough to jolt you awake and that's it. And then you just sort of lay there awake thinking 'What was that, an explosion or an earthquake?'

"I don't know how long it had been rattling before that, but that jolt definitely woke two of us up in the house. We lay awake for hours after that thinking 'What was that?'"

At the Onslow Ocean View Caravan Park, Vivien Spriggs says she and her husband woke to what sounded like something on the roof.

"We just woke up from a deep sleep and it sounded like something, an animal or something jumping around on the roof," she said.

"But of course we never thought anything about an earthquake, just being so sleepy.

"By the time we sort of came to and sat up, and we were thinking 'goodness what is that noise' and then it just stopped, so how long it took to wake us I'm not sure."

Ms Spriggs says she was sleeping with earplugs in, so it could have taken a while to wake her.

"We're from New Zealand and we get plenty over there so we must be used to it," she said.