FORCES that triggered the earthquake in China on Monday may have been born in the geological event that triggered the tsunami on Boxing Day 2004, killing more than 230,000 people, an Australian seismologist says.

Kevin McCue, an adjunct professor at Central Queensland University, warned it was a mistake to assume an equally powerful tremor could never hit an Australian city.

China's disaster, he said, had been caused by the relentless north-eastern drift of a tectonic plate on which both India and Australia ride. The slow-motion collision between India and the rest of Asia over the past 50 million years had pushed up the Himalayan mountains, raised the Tibetan plateau, and put pressure on geological faults beneath China.

Mr McCue suspected that the 9.1-magnitude quake that struck Sumatra on December 26, 2004, unleashing the tsunami across the Indian Ocean, had also forced stresses within the Earth's crust to "migrate" towards fault lines in south-western China.

"Once we crunch the numbers we will find the stress on this [Chinese] fault line increased as a result of the Sumatra earthquake," he said.

Seismologists describe the Chinese tremor as an intraplate event because, unlike the Sumatra quake, it struck about 500 kilometres from the nearest tectonic plate boundary. Mr McCue said only 10 per cent of all quakes happened in the middle of plates, rather than on their boundaries.

It was wrong to think Australia was immune from such events, he said. "After China, Australia is the next most active intraplate area in the world."

In 1909 the sea floor off Western Australia, part of Australia's intraplate, was hit by a 7.2-magnitude quake. The 1968 tremor that flattened the West Australian town of Meckering measured 6.8, and a 6.7 quake hit Tennant Creek in 1988.

"Adelaide, Sydney, Newcastle - most of our major cities - are close enough to large faults to accommodate an earthquake as big as the Chinese quake."

A huge quake that struck near Echuca 10,000 to 30,000 years ago was so violent it changed the Murray River's course and lifted one side six metres.

Mr McCue said a fault line near Lapstone, in the Blue Mountains, "is certainly big enough" to sustain a quake as powerful as China's.