Predicting wave-induced ripple equilibrium geometry

Author Posting. © American Geophysical Union, 2013. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Oceans 118 (2013): 3202–3220, doi:10.1002/jgrc.20241.A comprehensive database of existing (since 1954) field and laboratory measurements of ripple geometry is compiled and combined with newly collected field data to examine the performance of ripple equilibrium predictors. Reanalysis of this enlarged ripple geometry data set reveals that ripples formed from monochromatic waves scale differently than ripples formed from random waves for many existing ripple predictors. Our analysis indicates that ripple wavelengths from the two data sets collapse into a single scaling when the semiorbital excursion and sediment grain diameter are used as normalizing factors. Ripple steepness remains relatively constant for both regular and irregular wave conditions, and it only slightly increases for shorter ripple wavelengths. These findings allowed for the development of a new equilibrium ripple predictor suitable for application in a wide range of wave and sediment conditions.Financial support for this work was provided by the National Science Foundation (NSF awards OCE-0451989 and OCE-0535893) and by the South Carolina Coastal Erosion Project, a cooperative study supported by the U.S. Geological Survey and the South Carolina Sea Grant Consortium (Sea Grant Project R/CP-11).2013-12-2