Wind can significantly alter the shape of river canyons on Earth, according to a study published online in Nature Geoscience. Ancient canyons, thought to have been carved by flowing water on a wetter early Mars, may have been similarly reshaped by three billion years of wind action at the Martian surface.
Bedrock canyons are commonly found on Earth. Erosion by rivers is used to interpret the shape of these canyons, however many are also found in dry, windy environments. The potential for wind to sculpt these landforms is poorly understood. Jonathan Perkins and colleagues analysed a set of river gorges in the Andes of northeast Chile, where some of the canyons are exposed to strong regional winds and some are shielded. They find that the canyons exposed to wind are longer, wider and smoother than those influenced by water alone. Differences in canyon morphology are correlated with the strengths of winds passing over the landscape, suggesting that wind is indeed responsible for reshaping the canyons. This process may also occur on other windy worlds, such as Mars.
In an accompanying News & Views article, J. Taylor Perron writes that “future interpretations of planetary landscapes where wind is a dominant surface process will need to take this mechanism into account.”