ripple mark

ripple mark
1. one of the wavy lines or ridges produced, esp. on sand, by the action of waves, wind, or the like.
2. one of such forms preserved in sandstone or siltstone.
[1825-35]

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One of a series of small marine, lake, or riverine features, consisting of repeating wavelike forms with symmetric slopes, sharp peaks, and rounded troughs.

Ripple marks are formed in sandy bottoms by oscillation waves, in which only the wave form advances rapidly, the actual water-particle motion consisting of almost closed vertical orbits. The presence of the bottom restricts the lowermost orbits into nearly flat ellipses, and the bottom water moves back and forth rhythmically. If the maximum horizontal velocity of this motion is capable of moving the grains composing the bed, ripple marks develop. See also wave.

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      one of a series of small marine, lake, or riverine topographic features, consisting of repeating wavelike forms with symmetrical slopes, sharp peaks, and rounded troughs. Ripple marks are formed in sandy bottoms by oscillation waves, in which only the wave form advances rapidly, the actual water-particle motion consisting of almost closed vertical orbits that migrate landward only very slowly. The orbital motion at the surface is communicated downward with diminishing strength; but if the water depth is less than about one-half of the wave length, water motion is still significant near the bottom. The presence of the bottom restricts the lowermost orbits into nearly flat ellipses, however, and the bottom water moves rhythmically to and fro. If the maximum horizontal velocity of this motion is capable of moving the grains composing the bed, ripple marks develop. Any minor prominence on the bottom determines the position of alternate vortices on either side, and a sharp ridge with symmetrical slopes eventually forms. The crestal spacing of a ripple train is equal in length to the average length of oscillatory paths near the bed.

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Universalium. 2010.

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  • ripple mark — n. any of the ripply lines on the surface of sand, mud, etc. caused by waves, wind, or both …   English World dictionary

  • ripple mark — noun one of a series of small ridges produced in sand by water currents or by wind • Hypernyms: ↑ridge * * * noun 1. a. : the undulating surface of a ridge or trough produced in incoherent granular material (as loose sand) by wind, currents of… …   Useful english dictionary

  • ripple mark —    An undulating surface of alternating, subparallel, small scale ridges and depressions, commonly composed of loose sand. It is produced on land by wind and under water by the agitation of water by currents or wave action, and generally tends at …   Glossary of landform and geologic terms

  • ripple mark — noun Date: 1833 1. one of a series of small ridges produced especially on sand by the action of wind, a current of water, or waves 2. a striation across the grain of wood especially on the tangential surface • ripple marked adjective …   New Collegiate Dictionary

  • ripple mark — rip′ple mark n. 1) gel one of the wavy lines or ridges produced, esp. on sand, by the action of waves, wind, or the like 2) gel one of such forms preserved in sandstone or siltstone • Etymology: 1825–35 …   From formal English to slang

  • ripple mark —    A wavelike sculpture on water covered sand surfaces obtained by wave action [16] …   Lexicon of Cave and Karst Terminology

  • ripple mark — /ˈrɪpəl mak/ (say ripuhl mahk) noun one of the wavy lines or ridges produced on sand, etc., by waves, wind, or the like …  

  • ripple-mark — …   Useful english dictionary

  • -mark — ripple mark …   Dictionnaire des rimes

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