Dune
Question: When the tide recedes on a sandy beach, ripples are left in the sand with a fairly constant length and direction. What influences their direction, length and height?
Answer: Ripples on beaches are generated by waves and/or currents. Those formed by waves should have a symmetrical profile, with pointed crests and rounded troughs.
These crests will, typically, divide along their length. The distance between successive ripples (wavelength) is determined by the grain size of the sediment, wave height and water depth. Waves are only able to move sediment in water depths of less than half their wavelength.
Ripples…
