NORTH Queensland has been rocked by a 5.4 magnitude earthquake, with reports from across the region of buildings "shuddering''.
The quake struck at 3.31pm, about 30km southeast of Townsville.
A preliminary report by Geoscience Australia has the 5.4 magnitude earthquake rupturing on land between Bowen and Ayr.
The United States Geological Survey says the quake struck at a depth of 10km and initially had the quake listed as a 5.2 magnitude tremor.
The Joint Australian Tsunami Warning Centre issued a brief statement saying there was no threat of a tsunami to the Australian mainland or islands.
Either way, the afternoon jolt is a significant magnitude earthquake by local standards and is the biggest recorded quake on the Australian mainland in years.
Earthquake experts said the earthquake could have been felt by people up to 250km away, with damage possible up to 20 km from the epicentre.
At The Sunday Mail's North Queensland bureau in Townsville, the building shuddered with the tremor lasting a matter of seconds.
Townsville residents reported homes shaking, while emergency crews were scrambling to find out if any damage had occurred.
A Department of Community Safety spokeswoman said there had been no reports of damage at this stage.
Queensland Fire and Rescue Service crews in the northern region said there had been no reports of damage immediately after the earthquake.
They said it was a ``big one'', and would have been felt by people right across the region.
Remarkably, only a matter of minutes later, Christchurch - the scene of the devastating earthquake only weeks ago - was hit by a 5.3 magnitude aftershock.
The 5.49pm (local time) quake was centred 10km northeast of Diamond Harbour, at a depth of 11km and was felt strongly in Christchurch, GNS reported.
Christchurch remains devastated following a magnitude 6.3 quake on February 22, which claimed an estimated 181 lives.
That quake followed a magnitude 7.1 quake last September 4.
