Exploring the relationship between nearshore morphology and shoreline change

Nearshore bathymetry data collected along the US Pacific Northwest is analyzed to determine relationships between nearshore morphology and shoreline change at a variety of spatial scales. Sandbar properties are compared at three sites, locations separated by tens of kilometers but subject to similar hydrodynamic forcing and having like sediment characteristics. These three sites, an accreting coast, an eroding coast, and a dynamically stable coast, are shown to exhibit different large-scale coastal behaviour. The nearshore profile slopes at these locations are correlated with recent shoreline change history. Measurements have revealed offshore trending sandbars that are continuous over alongshore distances of tens of kilometers, behaviour that spatially mimics the net offshore bar migration documented on several other coasts.