Unravelling the mystery of miniature dunes on Earth and Mars
Scientists from the University of Southampton have discovered how miniature dunes form on Earth and Mars. The research could help us understand similar formations on other planets.
The scientists from the University of Southampton in England, in collaboration with research institutes in France, have uncovered the mechanism behind the formation of miniature dunes on beaches and in deserts. The research findings, published in the scientific journal "PNAS," shed new light on the formation of so-called "proto dunes" on Earth and may also provide information about similar structures on Mars and other planets.
They captured the process of dune formation using a laser
"These are the kind of smaller scale sand bedforms that people would see forming before their eyes on the beach before the wind stops or the waves wash them away," explained Professor Jo Nield, who led the research, to the SciTechDaily portal. Previous theories regarding large desert dunes did not explain how these smaller formations arise on damp surfaces, such as beaches or hard, gravelly areas.
An international research team, with members from Southampton, Paris, Oxford, Loughborough, Illinois, and Denver, captured for the first time the process of forming these small dunes using high-resolution laser scanning in the Namibian desert. They discovered that sand moving over harder, more consolidated surfaces bounces higher and is more easily transported by the wind. When it lands on a softer, rippled surface, the sand accumulates.
"Proto dunes" are also on Mars
Professor Philippe Claudin from the French National Centre for Scientific Research (CNRS) added that the model can almost perfectly recreate what we see in our field data. "Interestingly, we see similar patterns in arid areas with gravel and coastal areas where there's moisture," he explained. The model enables the team to adjust various parameters, such as the amount of sand and wind strength, to explore different scenarios.
These "proto-dunes" are not exclusive to Earth. The research team is currently examining dune formation on Mars. Professor Nield points out their enthusiasm about applying Earth-based knowledge to the Martian landscape and gaining insight into the similarities and differences in proto-dune development on both planets.
