Locals reported it feeling like a “semi-trailer hitting”, and some cracks appeared in homes and businesses.
It comes as a “swarm” of 36 mini quakes hit the region in recent days with the tremors set to continue.
Senior seismologist at Geoscience Australia Hugh Glanville said it is unlikely the quakes will stop any time soon.
He said: “We don’t know if that will happen, but there’s always a chance so we always like to encourage people to get educated.”
“Given the current activity residents are likely to feel more earthquakes occurring as there’s no reason for us to suspect that activity will stop.
“While it’s rare and none of these earthquakes have been big, there is always a chance that a bigger earthquake can occur.”
Geoscience Australia insists it is not unusual to get swarms like this, but said a larger quake cannot be discounted.
It said: “There is no way of predicting earthquakes or if we will have anymore bigger or smaller.
“There to date has been no injuries or damage as a result of earthquakes.”
No tsunami warning has been put in place in the area.
Many took to Facbeook to share their experience of the Coff’s Harbour quake.
One said it was “like a 747 plane in my front yard only under my feet.
“It went on for a minute I’m sleeping in my car from now on too, at least it has rubber wheels and not a tiled roof. It’s so frightening here now. I’m stocking up on food and water and candles.”
Another added: “Sounded like someone had thrown themselves onto the ground upstairs (a very big and heavy person.”
This is the latest quake to hit the Ring of Fire bringing terror to Alaska, Papua New Guinea, Mexico, Indonesia, Hawaii and Chile while Japan has seen the spectacular eruption of Mount Kusatsu-Shirane.
The Ring of Fire is the largest and most active fault line in the world, stretching from New Zealand, all around the east coast of Asia, over to Canada and the USA and all the way down to the southern tip of South America.
And in the last 24 hours, scores more earthquakes have hit the zone.
Chile was hit by a strong 5.4 magnitude tremor at 7.45 GMT and a 7.9 magnitude earthquake hit Alaska yesterday, promoting a tsunami warning the state and Canada’s British Columbia, leading residents to flee inland.