4.7 Article

Largest wind ripples on Earth?

期刊

GEOLOGY
卷 37, 期 4, 页码 343-346

出版社

GEOLOGICAL SOC AMER, INC
DOI: 10.1130/G25382A.1

关键词

-

类别

向作者/读者索取更多资源

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 similar to 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/cm(3)), although crests are exclusively composed of varnished, normal-density clasts (2.43 g/cm(3)). 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.

作者

我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。

评论

主要评分

4.7
评分不足

次要评分

新颖性
-
重要性
-
科学严谨性
-
评价这篇论文

推荐

暂无数据
暂无数据