Rapid headward erosion of marsh creeks in response to relative sea level rise Academic Article uri icon

abstract

  • Tidal creeks in Cape Romain, South Carolina, are extending rapidly onto the established marsh platform producing an unusual morphology, which remains self-similar in time. A time-series of aerial photographs establishes that these channels are headward eroding at an approximate rate of 1.9 m/yr. The rapid rate of headward erosion suggests that the marsh platform is in disequilibrium and unable to keep pace with high local relative sea level rise (RSLR >3.2mm/yr) through accretionary processes. Biological feedbacks play a strong role in the morphological development of the creeks. Dieback of vegetation coupled with intense burrowing by crabs produces a bare and topographically depressed region beyond the channel head toward which the channel head extends. We examine the mechanisms producing this headward extension and pinnate channel morphology, and report a new pattern of creek incision in a regime of rapid RSLR. Citation: Hughes, Z. J., D. M. FitzGerald, C. A. Wilson, S. C. Pennings, K. Wieski, and A. Mahadevan (2009), Rapid headward erosion of marsh creeks in response to relative sea level rise, Geophys. Res. Lett., 36, L03602, doi: 10.1029/2008GL036000.

publication date

  • February 2009