RipplesThis pattern of troughs and peaks on a scale of centimeters is one of the most common sedimen
RipplesThis pattern of troughs and peaks on a scale of centimeters is one of the most common sedimentary structures on Earth. All that is required to form ripples is loose sediment and a strong enough flowing current such as wind or water. When the fluid moves fast enough, it exerts a force on the loose grains at the surface, causing a few of them to start moving. Once some grains start moving, they begin bouncing across the surface, even dislodging other grains when they come down, in a process called saltation. Ripples form from small-scale variations that disturb the airflow, causing sand to accumulate at some spots and move away at others. The size and spacing of ripples is a function of the type of sediment being transported and the speed of the current. The bigger the sand is and the faster the current flows, the bigger the ripples become and the farther apart they are spread.The process of grain flow is a complicated one, with many distinct forces and turbulence that needs to be characterized to understand all the details. Geoscientists are working to understand ripple generation using a variety of techniques, including supercomputer simulations and full-scale experiments. Ripples are found in the geologic record and on other planets, so the better we understand their formation the more information we can get by observing them.-JBBImage credit: Julie Francoishttps://flic.kr/p/QogbGQExamples of science and references:http://geomorphology.geo.arizona.edu/PAPERS/pelletier_09.pdfhttp://www.nature.com/articles/srep11390https://eos.org/research-spotlights/wave-ripples-spaced-flow-downstream-ripple-peakshttp://adsabs.harvard.edu/abs/2009Geomo.105..322Phttps://pubs.usgs.gov/gip/deserts/eolian/ -- source link
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