A unifying framework for shoreline migration: 2. Application to wave-dominated coasts

Journal Article (Journal Article)

The Bruun rule, widely used to predict transgression due to sea level rise on decade to century timescales based on a fixed nearshore profile, neglects the influence of inland topography and substrate lithology, leading to physically unreasonable predictions on longer timescales. We use a new approach, the shoreline Exner equation, to model shoreline transgression on wave-dominated coasts over timescales of decades to millennia. Our results show that interactions between nearshore processes and inland topography, neglected by Bruun-style models, drive morphologic evolution which modulates shoreline retreat. Analytical solutions suggest that while short-term shoreline retreat will sometimes follow the Bruun rule, long-term transgression will always follow the slope of the inland topography. Moreover, our results show that the slope of the inland landscape, relative to the nearshore slope, exerts a first-order control on coastal morphology, such that steep coasts tend to form cliff-backed beaches while gentle coasts tend to form barrier island-lagoon systems. However compositional variations between the inland landscape and nearshore system can alter this pattern. Copyright 2009 by the American Geophysical Union.

Full Text

Duke Authors

Cited Authors

  • Wolinsky, MA; Brad Murray, A

Published Date

  • March 1, 2009

Published In

Volume / Issue

  • 114 / 1

Electronic International Standard Serial Number (EISSN)

  • 2169-9011

Digital Object Identifier (DOI)

  • 10.1029/2007JF000856

Citation Source

  • Scopus