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dc.contributor.authorAshton, Andrew D.
dc.contributor.authorGiosan, Liviu
dc.date.accessioned2011-08-02T13:20:12Z
dc.date.available2012-01-07T09:30:34Z
dc.date.issued2011-07-07
dc.identifier.citationGeophysical Research Letters 38 (2011): L13405en_US
dc.identifier.urihttp://hdl.handle.net/1912/4736
dc.descriptionAuthor Posting. © American Geophysical Union, 2011. 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 38 (2011): L13405, doi:10.1029/2011GL047630.en_US
dc.description.abstractWave-influenced deltas, with large-scale arcuate shapes and demarcated beach ridge complexes, often display an asymmetrical form about their river channel. Here, we use a numerical model to demonstrate that the angles from which waves approach a delta can have a first-order influence upon its plan-view morphologic evolution and sedimentary architecture. The directional spread of incoming waves plays a dominant role over fluvial sediment discharge in controlling the width of an active delta lobe, which in turn affects the characteristic rates of delta progradation. Oblique wave approach (and a consequent net alongshore sediment transport) can lead to the development of morphologic asymmetry about the river in a delta's plan-view form. This plan-form asymmetry can include the development of discrete breaks in shoreline orientation and the appearance of self-organized features arising from shoreline instability along the downdrift delta flank, such as spits and migrating shoreline sand waves—features observed on natural deltas. Somewhat surprisingly, waves approaching preferentially from one direction tend to increase sediment deposition updrift of the river. This ‘morphodynamic groin effect’ occurs when the delta's plan-form aspect ratio is sufficiently large such that the orientation of the shoreline on the downdrift flank is rotated past the angle of maximum alongshore sediment transport, resulting in preferential redirection of fluvial sediment updrift of the river mouth.en_US
dc.description.sponsorshipThis research was supported by NSF grants EAR‐0952146 and OCE‐0623766, the Exxon‐Mobil Upstream Research Company, and the WHOI‐USGS postdoctoral fellowship.en_US
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dc.language.isoen_USen_US
dc.publisherAmerican Geophysical Unionen_US
dc.relation.urihttp://dx.doi.org/10.1029/2011GL047630
dc.subjectDepositional asymmetryen_US
dc.subjectLarge-scale coastal evolutionen_US
dc.subjectNumerical modelingen_US
dc.subjectPlan-view delta evolutionen_US
dc.titleWave-angle control of delta evolutionen_US
dc.typeArticleen_US
dc.identifier.doi10.1029/2011GL047630


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