Wave-formed ripple Wave-formed ripple In sedimentology, wave-formed ripples or wave-formed ripple marks are a feature of sediments (sandstones, limestones, siltstones) and dunes. These ripple marks are often characterised (and thus distinguished from current ripples) by symmetric cross sections and long relatively straight crests, which may commonly bifurcate. Commonly, these crests can be truncated by subsequent flows. Their wavelength (periodicity) depends on the sediment grain size, water depth and water-particle orbits in the waves. On tidal flats the pattern of wave-formed ripples may be complicated, as a product of changing depth and wind and tidal runoff directions. Symmetrical ripples are commonly found in
Wave cloud Wave cloud A wave cloud is a cloud form created by atmospheric internal waves. The atmospheric internal waves that form wave clouds are created as stable air flows over a raised land feature such as a mountain range, and can form either directly above or in the lee of the feature. As an air mass travels through the wave, it undergoes repeated uplift and descent. If there is enough moisture in the atmosphere, clouds will form at the cooled crests of these waves. In the descending part of the wave, those clouds will evaporate due to adiabatic heating, leading to