Largest wind ripples on Earth?

Abstract

Research Article| April 01, 2009 Largest wind ripples on Earth? Juan Pablo Milana Juan Pablo Milana 1InGeo—CONICET, Universidad Nacional de San Juan, 5401 San Juan, Argentina Search for other works by this author on: GSW Google Scholar Author and Article Information Juan Pablo Milana 1InGeo—CONICET, Universidad Nacional de San Juan, 5401 San Juan, Argentina Publisher: Geological Society of America Received: 29 Jul 2008 Revision Received: 09 Dec 2008 Accepted: 11 Dec 2008 First Online: 02 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 © 2009 Geological Society of America Geology (2009) 37 (4): 343–346. https://doi.org/10.1130/G25382A.1 Article history Received: 29 Jul 2008 Revision Received: 09 Dec 2008 Accepted: 11 Dec 2008 First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Juan Pablo Milana; Largest wind ripples on Earth?. Geology 2009;; 37 (4): 343–346. doi: https://doi.org/10.1130/G25382A.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Unique wind ripples attaining heights to 2.3 m, wavelengths to 43 m, and a crest maximum grain size of 19 mm occur on the Argentine Puna Plateau at ~4000 m altitude. These are the largest ripples reported on Earth, comparable only to Mars counterparts. They form in the presence of high proportions of low-density pumice clasts (0.91 g/cm3), although crests are exclusively composed of varnished, normal-density clasts (2.43 g/cm3). Mature ripple profiles are partly excavated on bedrock, so they form by a combination of deflation, winnowing of finer grains, minor wind drift of fine gravel, and lagging of clasts >4 cm. The large ripple size appears to be related to strong winds, dense saltation layers, and a long time for evolution. Ripple sizes are smaller on obstacles, as compared to flat terrain; there is a lack of correlation between clast size, wavelength, and the extreme ripple size (in spite of the thin atmosphere), all of which suggest that while small-scale gravel ripples may form according to a reptation model, their evolution into large-scale types may relate to aerodynamic instabilities originating at the saltation curtain–air interface. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.