Sand Dunes ‘Communicate’ as They Migrate
by Brigit Katz/Smithsonianmag.com
Sand dunes are among nature’s loveliest wonders, forming undulating mounds in deserts, on beaches, and even underwater. Dunes are also known to migrate—and now a new study suggests that they “communicate” as they move.
Of course, as inanimate objects, the dunes are not speaking; the new research, published in the journal Physical Review Letters, focuses on how the mounds behave as they get whipped about by wind and water flow. Dunes rarely occur on their own, but instead “form striking collectives known as dune fields or dune corridors,” the study authors write. These clusters move downstream with wind and water flow, and smaller dunes are known to move faster than larger ones. But how—or even if—the dunes interact with one another has been the subject of debate.
“There are different theories,” explains Karol Bacik, a Ph.D. candidate at Cambridge University and first author of the paper. “[O]ne is that dunes of different sizes will collide, and keep colliding, until they form one giant dune, although this phenomenon has not yet been observed in nature.” Another theory posits that dunes collide and exchange mass, “sort of like billiard balls bouncing off one another…