A surfzone morphological diffusivity estimated from the evolution of excavated holes
MetadataShow full item record
Downslope gravity-driven sediment transport smooths steep nearshore bathymetric features, such as channels, bars, troughs, cusps, mounds, pits, scarps, and bedforms. Downslope transport appears approximately as a diffusive term in the sediment continuity equation predicting changes in bed level, with a morphological diffusivity controlling the rate of seafloor smoothing. Despite the importance of surfzone sediment transport and morphological evolution, the size of the downslope transport term in nearshore models varies widely, and theories have not been tested with field measurements. Here observations of the infill of large excavated holes in an energetic inner surf zone provide the first opportunity to infer the morphological diffusivity in the field. The estimated diffusion coefficient is consistent with a theoretical bedload morphological diffusivity that scales with the three-halves power of the representative bed shear stress.
Author Posting. © American Geophysical Union, 2014. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 41 (2014): 4628–4636, doi:10.1002/2014GL060519.
Showing items related by title, author, creator and subject.
McNichol, Ann P. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1986-09)A study of the remineralization of organic carbon was conducted in the organic-rich sediments of Buzzards Bay, MA. Major processes affecting the carbon chemistry in sediments are reflected by changes in the stable carbon ...
Sources of land-derived runoff to a coral reef-fringed embayment identified using geochemical tracers in nearshore sediment traps Takesue, Renee K.; Bothner, Michael H.; Reynolds, Richard L. (Elsevier B.V., 2009-09-24)Geochemical tracers, including Ba, Co, Th, 7Be, 137Cs and 210Pb, and magnetic properties were used to characterize terrestrial runoff collected in nearshore time-series sediment traps in Hanalei Bay, Kauai, during flood ...
Hsu, Tian-Jian; Liu, Philip L.-F. (American Geophysical Union, 2004-06-18)We present two depth- and phase-resolving models, based on single- and two-phase approaches for suspended sediment transport under water waves. Both models are the extension of a wave hydrodynamic model Cornell Breaking ...