GEOLOGISTS are trying to work out how a boy, six, was buried alive in a sand dune, in an event they say defies the laws of physics.

ScienceAlert.com reports that the boy, only named as Nathan, was playing on the Mount Baldy sand dune in Lake Michigan. At 37 metres it is the tallest sand dune on the southern shore of the lake and is believed to be 4500 years old.

Scientists say a wild storm meant the dune was able to shift its mass in ways they don’t yet understand.

The hole that Nathan fell through ended up connecting to a much larger hole within. All that was left was a 30cm hole.

Nathan’s voice could be heard telling his parents he was scared, but there was no way anyone could see him.

His unconscious body was retrieved from the depths of the dune 3.5 hours later.

“We’re seeing what appears to be a new geological phenomenon,” said geologist Erin Argyilan, who was at the scene doing routine measurements on the dune at the time of the incident.

Alan Arbogast, a Michigan State University geographer and leading expert on the Michigan dunes, agrees.

“For sand to accumulate in a way that would leave holes or caverns in the subsurface doesn’t at first glance make a whole lot of sense,” he said.

Dr Argyilan’s colleague Zoran Kilibarda had taken measurements across Mount Baldy that showed the entire dune had shifted 134 metres away from the lakefront between 1938 and 2007.

It took 3.5 hours of excavation, with robotic probes and giant digging vehicles, to get Nathan out. He was found just after 8pm that night, huddled unconscious in one of the winding holes.

Nathan walked out of hospital two weeks later with doctors believing an air pocket may have been what saved his life.

The dune is now closed off to the public completely.