Geelong has been jolted by a small earthquake in the early hours of the morning.

It struck just after 3.30 and was centred to the city’s north-west, measuring 2.3 on the Richter scale.

But while it may have been a relatively minor tremor it was certainly noticed by residents.

Several people said they thought their nightmare of an explosion at Corio’s Shell refinery had finally come true.

“ My dogs were going berserk barking and … there was a huge bang, a couple more barks, then silence – I thought Shell or the LPG site had gone up,” said Annette Butcher of Corio.

Many people took to Facebook to say they were woken by the quake.

One said, “My whole unit shook all the windows were shaking like mad I thought they were gonna smash.”

Another person reported, “Rumbled (sic) noise, dog going berserk,woke me up, bedside lamps shook and windows, live near power plant. Damn scary. Then complete silence.”

Geelong has never been hit by a major earthquake but smaller tremors are not uncommon.

The most recent quake measuring over five on the Richter scale was in 1965 but more than one hundred smaller incidents have been recorded over the last 170 years.

There are numerous fault lines near Geelong with the biggest located to the city’s north, known as the Lovely Banks Fault.

Experts say it has a “scarp” (surface displacement) of over 100 metres, the second largest in Australia.

The Rowsley Fault starts about 16km west of Geelong and was the cause of a 4.7 magnitude quake that shook Balliang in 1977.

Picture: Despite the perception that Australia is relatively earthquake-free, this earthquake map from the University of Western Australia shows just how common they really are.