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
Coda Wave Interferometry The unperturbed travel time is given by formula_8 where formula_9 is the coda wave velocity. The perturbed travel time is formula_10 where formula_11 is the velocity perturbation. Thus formula_12 . If the relative velocity perturbation is assumed constant, then formula_13 where t is the center time of the employed time window. Thus, the travel time perturbation depends on the arrival time of the coda wave, but not of the particular path followed. Coda Wave Interferometry Coda Wave Interferometry is an ultrasound technique for detection of weak and local changes in complex inhomogeneous media. Sound waves that travel through a medium