Erosion Strikes Again!14 July 2017
If you have seen the photo below, then you have witnessed Mars’ famous upside down stream channels. How were these once flowing stream channels now flipped upside down you ask? Erosion is to blame! The infamous and sometime elusive erosion is not only found to be a troublemaker on Earth, but also on Mars. Erosion is responsible for the breakdown and movement of rock and soil. Mountains weathering away to nothing or the formation of vast canyons, such as the Grand Canyon, are the result of erosion. As for Mars’ upside down stream channels, after running water in a channel dries up, erosion creeps in and takes over. The surface around the channel erodes down and causes the channel to become inverted, referred to as a sinuous ridge.
Amber Gullikson and Ryan Anderson are working on mapping these features to understand where they are concentrated and what they can tell us about the past climate on Mars. While they’re at it they are also mapping valleys, canyons, and other channels at a higher resolution than has been done before. Follow the link below to learn more about this work and why Ryan and Amber are focusing on Northwest Hellas, Mars.
Image Credit: CTX
Excerpt: “Evidence for flowing water on the surface of Mars has been recognized since the Mariner 9 mission, when images were returned showing extensive dendritic valley networks . With increasingly high resolution images afforded by more recent orbiter missions, numerous potential fluvial features such as stream channels, gullies, and sinuous ridges have been identified. The work presented here focuses on sinuous ridges, which are interpreted to be either inverted fluvial channels or eskers [e.g. 2-6]. Although related to flowing liquid water, sinuous ridges are understudied in comparison to Martian valley networks. Sinuous ridge occurrences were documented on a global scale using data from the Mars Orbital Camera (MOC)  and the Thermal Emission Imaging System (THEMIS)  by , but no large-scale maps tracing the morphology of these features, comparable to the global maps of valley networks [10,11], exists. We present the results of an ongoing effort to map sinuous ridges in a large region of interest (-15°N to -45°N, 30°E to 75°E) in northwestern Hellas.”
By Janet Richie