A Pacific island that seems to have disappeared from the Coral Sea between Australia and New Caledonia may simply have been created by human error in the first place, a scientist says.

Sandy Island, which is seen on numerous maps, nautical charts and even Google Earth, has captured the popular imagination after a team of geologists travelling by ship through the area found to their amazement that it wasn't there.

'The maps of Mars and the moon are much higher resolution and coverage than what we have of our own oceans.' —Sabin Zahirovic, geologist

Now one of the Australian scientists involved says mistakes made by those who transferred cartographers' charts to digital form may be at the root of the mysterious island's appearance and disappearance.

"It's completely possible that it was a human error in digitizing these maps at some stage," geologist Sabin Zahirovic of the University of Sydney told Reuters.

"And it's just entered the databases once, and it's stuck around inside the databases, because no scientific vessels have actually been in that region for a very, very long time."

Zahirovic explained that, like much of the world's oceans, the Coral Sea is actually a poorly explored area.

"The maps of Mars and the moon are much higher resolution and coverage than what we have of our own oceans," he said. "So we really need to go back and send more vessels and research vessels out there to map the ocean floor and better understand what's out there."

Sandy Island appeared to lie about 1,200 kilometres due east of the Queensland, Australia, coast toward the French-held archipelago of New Caledonia.

A team of geologists from the University of Sydney, led by Marie Seton, made a 25-day voyage through the area aboard a research vessel, ending earlier this month. They were exploring and compiling information about the sea floor.

When they came to the area where Sandy Island should have been visible, however, they found only blue sea.

"We became suspicious when the navigation charts used by the ship showed a depth of 1,400 metres in an area where our scientific maps and Google Earth showed the existence of a large island," Seton told the Sydney Morning Herald.

The project gathered 197 different rock samples and mapped more than 14,000 square kilometres of the ocean floor.