Interpreting Dune Patterns: Insights from Earth and Mars

A recent study published in the journal Geology attempts to interpret the patterns of dunes, which are sand mounds frequently formed by aeolian (wind) processes and range in size from small ripples observed on beaches to massive structures observed in the desert. Specifically, the researchers focused on patterns of dune crestlines, which are the top of the dunes. Different dune crestline patterns might appear as mundane features, but their formations are often the result of a myriad of influences, including climate change, surface processes, and atmospheric phenomena.

However, questions pertaining to the processes responsible for the different crestline patterns have baffled scientists. But the findings from this recent study could provide researchers insights into environmental variances not only on Earth, but other dune-harboring planetary worlds in our own solar system. These currently include three of the four terrestrial planets, Venus, Earth, and Mars; smaller bodies such as Jupiter’s volcanic moon, Io; Saturn’s largest moon, Titan; and even dwarf planet Pluto.

“When you look at other planets, all you have is pictures taken from hundreds to thousands of kilometers away from the surface,” said Dr. Mathieu Lapôtre, who is an assistant professor of Earth and planetary sciences in the Stanford Doerr School of Sustainability, and a co-author on the study. “You can see dunes – but that’s it. You don’t have access to the surface. These findings offer a really exciting new tool to decipher the environmental history of these other planets where we have no data.”

Dune interactions are defined as when their crestlines are near one another, and it’s these interactions result in the dunes establishing a balance, or equilibrium, with their surrounding environment. Therefore, the researchers hypothesized that a large amount of dune interactions could be interpreted as recent or nearby changes regarding those confined conditions.

For the study, the researchers analyzed changes in specific known environmental conditions, including sand quantity and wind direction, using orbital images of dune field sites numbering 30 and 16 on Earth and Mars, respectively. Examples of Earth dune field sites included Rice Valley, White Sands, the Namib Desert, and the Tengger Desert. Examples of Martian dune field sites included Nili Patera, Kaiser Crater, Rabe Crater, and Hargraves Crater.

Examples of active dune fields within Nili Patera on Mars. Dunes like these were examined for this study in hopes of giving scientists better insights into how their interactions are influenced by a planet’s climate. (Credit: NASA/JPL-Caltech/Univ. of Arizona)

Example of dune activity in Rabe Crater on Mars, one of the locations for this recent study investigating dune interactions. (Credit: NASA/JPL-Caltech/UArizona)

Example of dune activity in Kaiser Crater on Mars, one of the locations for this recent study investigating dune interactions. (Credit: NASA/JPL-Caltech/UArizona)

For Earth, the researchers flattened a dune field in China’s Tengger Desert to establish a baseline prior to analyzing satellite imagery between 2016 and 2022 of how this flat terrain evolved into large dunes as they slowly reached a state of equilibrium with their surrounding environment. This was followed by the team examining how wind conditions in the