A small aftershock has been felt almost 12 hours after a 4.6-magnitude earthquake struck the NSW Hunter region.

The first quake hit at 2.55am, and sent shockwaves spanning the coast from Taree down to Wollongong, including Sydney.

The first quake struck 10km underneath the town of Singleton, west of Newcastle and about 200km north of Sydney.

About 12 hours later, at 2.57pm, a small aftershock with a magnitude of 2.7 hit the same area.

It was recorded at a depth of 5 kilometres, and while the morning’s quake was felt as far away as northern NSW, only a small number of people reported feeling tremors from the aftershock.

This morning, the agency said the shock was the eleventh quake with a magnitude of 3.0 or more to hit the region in the last year.

Seismologist Professor Phil Cummins told Today the earthquake was relatively large by Australian standards.

“Normally, we regard magnitude 5 as the level at which substantial damage can occur,” he said.

“But, you know, it’s possible that even for an earthquake of magnitude 4.6, you you might get some damage.

“It certainly would have shaken people over a very wide area.”

He said the quake, which was felt as far as the Queensland border and in Canberra, was centred in an earthquake-prone part of Australia.

“We have had a large number of earthquakes in that Hunter Valley region, mostly up towards Muswellbrook.

“There have been two earthquakes of this size there over the past year, and then many more that were smaller than that.”

In 1989, a 5.6 magnitude earthquake in Newcastle killed 13 people and devastated the city.

Thousands of Sydney residents across the city reported their homes rattling overnight, with most of the tremors felt in the suburb of Wentworth Point.

Police say there are no initial reports of injuries or damage in the Hunter region.

The Joint Australian Tsunami Warning Centre said the quake was not a tsunami threat to the Australian mainland, islands or territories.