You may have heard of the incident about a year and a half ago in which a six year-old boy vanished while playing atop the Mount Baldy sand dune on the shore of Lake Michigan.
“He’s here. He’s right here,” the boy’s father was saying, Erin Argyilan, a geologist from the Indiana University Northwest, told Ariel Sabar at the Smithsonian Magazine. Argyilan was performing routine measurements on the dune at the time, and rushed over to help. While it’s unclear whether Nathan actually fell through a hole or dug one himself - which ended up connecting to a much larger hole within - all that was left of him when Argyilan arrived was a hole, about 30 cm in diameter. Nathan’s voice called out from the darkness 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, and Argyilan was flabbergasted. Dunes aren’t supposed to contain holes like this, according to science. “We’re seeing what appears to be a new geological phenomenon,” she told Angie Leventis Lourgos at The Washington Post earlier this year.
As it turned out, there was a whole netwok of caves and tunnels down there, and the kid was curled up in one of the larger caves. They had to bring in trackhoes and robotic probes to get to him, but he survived. And now we get to the mystery: sand, you know, isn't supposed to behave that way; voids, caves, and tunnels don't exist in your basic sand dune. So what makes Mount Baldy different?
Back in 2007, Argyilan’s colleague Zoran Kilibarda had taken scores of measurements across Mount Baldy and compared these to several aerial photographs to discover that the entire dune had shifted 134 metres away from the lakefront between 1938 and 2007, swallowing up long-forgotten trees, trails and stairs along the way.
Oh, but that's far from all; the 147 foot-tall thing's been eating homes and barns as well as trees and the occasional kid:
Already, the investigative team has found a home that was buried by sand after the Mount Baldy area joined the national lakeshore in the early 1970s. Researchers suspect more remain, perhaps with barns and sheds, as the houses stood uninhabited after the park service—and the dune—took over.
The team's using ground-penetrating radar, but that can only take them down to about half-way through the dune, so they're also collating old photos and descriptions of the area in an effort to build up a more comprehensive map of what's down there. Skiers are familiar with the snow wells that form around trees, and much the same could be going on under the dune as it shifts.
For now, they're guessing that as the buried stuff decomposes, voids are created. And it appears that there's a lot of buried stuff down there.
National Park Service has shut down public access to the site indefinitely.
