Huge wind-made cliffs
Mars is watching you…
October 13, 2014A way through
October 27, 2014
A piece of Mars: Topography in color is draped over an image of a windblown cliff. The entire shape of the landscape here was formed by wind, from the large 400 m (1312 ft) tall zigzag cliff, to the small streamlined shapes in the valley. Even the deep gorge that looks like a stream channel was formed by winds, all blowing toward the upper left. (HiRISE PSP_006694_1895 NASA/JPL/Univ. of Arizona, HRSC ESA/DLR/FU Berlin)
5 Comments
Hey Lori, I’ve witnessed this type of wind landscaping in snowfall at our beach house over Christmas week 2010 when Mother Nature dropped 30″+on us. Winds where directly North to South at 23 knots sustained for the 2 day snowfall event…the carving and piling up of the snow cliffs with tunnels bored right thru some 8 foot drifts was truly amazing.
BUT…))), how can wind sculpt cliffs from out of martian rock ?? To my untrained eye it appears water has worked its magic….
Please, please direct me to images of such wind blown rock or cliff formations here on Earth, I need to get my minds eye around this.
Thanks, William
Yeah, I know, it seems weird, doesn’t it? But it’s not just the wind: it’s sand-laden wind that abrades the surface (think sandpaper). This is a special place on Mars called the “Medusae Fossae Formation”, which is the largest collection of yardangs I’ve ever seen. I think that spot had the right combination of bedrock (massive, weakly cohesive) and lots of abrasion. I don’t know of any examples quite like this on Earth, but there are some fantastic yardangs in some terrestrial deserts:
Iran: https://maps.google.com/maps?ll=30.56135,58.12290&z=11&t=h&output=classic&dg=brw
Egypt: https://maps.google.com/maps?ll=25.60059,30.47454&z=13&t=h&output=classic&dg=brw
Peru (layers fluted by the wind): https://maps.google.com/maps?ll=-13.95849,-76.07184&z=14&t=h&output=classic&dg=brw
Cool! not one crater in sight! Is that because the sediments are continually in motion?
whoops i take that back..it’s only a few k in size..haha i didn’t notice your bar legend..)
Recently this unit has been dated to late Hesperian to early Amazonian (~3 Ga). The lack of small craters here shows that the surface has been eroded (by the wind, presumably) more recently than that, so we call that the “crater retention age”. There should be a few little craters here, and since there aren’t any, we know this is actively eroding today (or was very recently).