Residents on ‘s east coast have been rocked by tremors after a magnitude 5.0 earthquake left thousands without power just 24 hours earlier.
A magnitude 4.4 quake struck 8km north of the town of Denman, in NSW’s Hunter Region, at a depth of 9.6km just after 6.30am on Saturday.
It came just hours after a magnitude 3.2 earthquake shook the nearby town of Muswellbrook at 1.10am with another magnitude 2.5 quake felt at 2.30am.
Experts warned aftershocks would follow the larger quake on Friday with ns living over 170km away in Sydney reporting feeling tremors.
‘Anyone else just feel another tremor?’ a woman posted in a Facebook page for residents in Sydney’s eastern suburbs at 4.45pm on Saturday.
Geoscience senior seismologist Hadi Ghasemi earlier warned aftershocks would be felt throughout the day on Saturday.
‘Generally speaking, the largest aftershocks tend to occur at the earliest stages of the sequence,’ he told Nine’s Weekend Today.
‘As the time goes by, the frequency of the aftershocks start to decay too.’
Just over 24 hours earlier, mining operations were briefly halted after an earthquake struck the Mount Arthur Coal Mine just outside Muswellbrook at 12.01pm on Friday.
A spokesman for BHP said several miners were injured while underground.
‘A few team members at Mt Arthur Coal required first aid for minor injuries from falling items, thankfully no one was seriously hurt,’ he said.
‘All areas at site are conducting inspections before we safely restart operations. We have offered our support to the Muswellbrook Shire Council.’
A power outage hit an area in South Muswellbrook with the NSW State Emergency Service receiving 11 calls relating to minor residential damage and reports of minor infrastructure damage in Maitland and Muswellbrook.
As of 2pm of Friday, the largest aftershock had a magnitude of 2.9.
The tremors were felt hours away in Sydney’s west and southwest, the Central Coast and regional towns across the wider Hunter region.
UNSW geophysicist Stuart Clark said the quake was the biggest of six to hit the local area, a coal mining hub, in the past 50 years.
‘It’s a little smaller than the Newcastle earthquake, and there was another one 5.3 (magnitude) in 1994,’ associate professor Clark said.
‘The cause is compressional forces across the continent but the trigger is potentially coal mining.’
He warned of aftershocks in the next two days, saying ‘there might be a cluster of aftershocks typically a little bit smaller than this one’.
‘They don’t have to follow major earthquakes but they can.’
Muswellbrook Shire Council mayor Steven Reynolds said he was lying in bed when the house shook hard.
‘I tell you what, I thought the roof was coming down on me,’ Mayor Reynolds said.
‘You couldn’t miss it, it was big. We have the blasts here from the mines and I immediately knew it was nothing like that. I thought for sure it was an earthquake and there could have been some severe damage.’
Sydney residents also reported feeling shakes.
‘My apartment just moved.. who else felt it (earthquake) in Sydney?!’ posted one.
‘Was there just an earthquake in Sydney, or did my building just shake for fun?!’
A third said: ‘Just felt an actual earthquake in Sydney. Wall mounted TV was shaking as was the bed I was sitting on. Wild!’