Strange sand chess pieces dot the shore of Lake Michigan. Here’s how they formed.
Bizarre sand sculptures rising from the beach at Lake Michigan caught the eye of at least two photographers in early January, who posted their images of the wonders of nature online.
But what are these sand statues and how did they become?
Their construction depends on several factors, including sand and water content and wind conditions, said Daniel Bonn, physicist and director of the van der Waals-Zeeman Institute at the University of Amsterdam.
Related: Photos of the mysterious shapes of sand dunes
The pillars, sometimes called hoodoos, had different heights, ranging from 3 to 20 inches (7.6 to 51 centimeters) high, said Terri Abbott, a nature photographer who lives in northern Indiana. Abbott was visiting Tiscornia Park in St. Joseph, Michigan, on Jan. 8 when she noticed the stunning shapes on the snowy beach.
“Lying on the ground and shooting through these sculptures felt like a different planet,” Abbott told Live Science in a Facebook post. “They were frozen and hard to the touch. The intricate and ever so sharp edges made them look amazing in their own way.
Abbott had never seen such carvings before. “I couldn’t believe how perfectly chiseled they were,” she added.
Michigan is freezing winter temperatures helped set the stage for the strange chess-like pieces to form, according to Bonn, who was the lead researcher on “How to Build the Perfect Sandcastle,” a study published in the journal Scientific reports in 2012.
“Basically, I think there are liquid specks in the sand that freeze when it’s cold,” Bonn told Live Science in an email. The coast is a windy place, he noted. When sand-laden wind blows through these frozen slabs, two seemingly opposite actions occur: In one, some grains of sand can attach to the frozen slab, causing it to grow, he said. “This then forms a roughly cylindrical consolidated sandcastle-like structure,” Bonn said.
In another, the wind and the sand it carries can erode the sand pillars, carrying the sand away, which “leads to the rings and the asymmetrical shape of the cylinder,” Bonn said.
Some of the sand eroded from these pillars ends up elsewhere on the beach. In some photos, “you see that there are point structures downwind that result from the sandblasting of the cylinder,” he said.
Joshua Nowicki, a photographer based in southwestern Michigan, came across the same sand pillars at Tiscornia Park on January 7 and 8. Nowicki, who has seen similar sand structures before, noted that although rare, these pillars can occur at any time of the year, “if there is wet sand and sustained high winds for several days.” In most cases, “they only get bigger than a few centimeters high when the sand is frozen (from rain, sleet, spray from breaking waves),” Nowicki told Live Science in a E-mail.
The sand sculptures he saw this year “are some of the tallest I’ve ever photographed, with the largest measuring around 15 inches [38 cm] tall and a few inches in diameter,” Nowicki noted. “Along the beach there were at least six groups with thirty or more sand structures in one group, with one group having a few more.”
Most pillars don’t last long. Usually, within a few days “the wind completely erodes them or knocks them down; if the temperature exceeds the freezing point, they crumble; and often in winter they are quickly covered in snowdrifts,” Nowicki said.
Pillars in Tiscornia Park collapsed earlier this week as temperatures began to warm, Nowicki said. “The fact that they only exist for a short time makes them very special,” he said. “You have to be there at the right time to see them when the shape is still well defined.”
Originally posted on Live Science.