Geo-Marine Letters

, Volume 29, Issue 6, pp 441–453

Delta lobe degradation and hurricane impacts governing large-scale coastal behavior, South-central Louisiana, USA

  • Michael D. Miner
  • Mark A. Kulp
  • Duncan M. FitzGerald
  • James G. Flocks
  • H. Dallon Weathers
Original

DOI: 10.1007/s00367-009-0156-4

Cite this article as:
Miner, M.D., Kulp, M.A., FitzGerald, D.M. et al. Geo-Mar Lett (2009) 29: 441. doi:10.1007/s00367-009-0156-4

Abstract

A large deficit in the coastal sediment budget, high rates of relative sea-level rise (~0.9 cm/year), and storm-induced current and wave erosion are forcing barrier shoreface retreat along the periphery of the Mississippi River delta plain. Additionally, conversion of interior wetlands to open water has increased the bay tidal prism, resulting in degradation of barrier islands due to inlet widening, formation of new inlets, and sediment sequestration at ebb-tidal deltas. Single-beam bathymetric surveys along a 165-km stretch of south-central Louisiana barrier coast, from Raccoon Point in Terrebonne Parish to Sandy Point in Plaquemines Parish, were conducted in 2006. These data, combined with historical bathymetry from three time periods (dating to the 1880s), provide a series of digital elevation models that were used to calculate sediment volumetric changes and determine long-term erosional-depositional trends. Dominant patterns during the 125-year period include (1) erosion of ~1.6 × 109 m3 from the shoreface, forcing up to 3 km of shoreface retreat, (2) sediment deposition in coastal bights and at ebb-tidal deltas, and (3) a combined increase in tidal inlet cross-sectional area from ~41,400 m2 to ~139,500 m2. Bathymetric and shoreline change datasets separated by shorter time periods (sub-annual) demonstrate that these long-term trends are driven by processes associated with major hurricane impacts, and that rates of shoreface erosion are an order of magnitude greater during active hurricane seasons compared to long-term trends.

Supplementary material

367_2009_156_MOESM1_ESM.pdf (2.8 mb)
Supplementary material, approximately 2.84 MB.

Copyright information

© Springer-Verlag 2009

Authors and Affiliations

  • Michael D. Miner
    • 1
  • Mark A. Kulp
    • 2
  • Duncan M. FitzGerald
    • 3
  • James G. Flocks
    • 4
  • H. Dallon Weathers
    • 1
  1. 1.Pontchartrain Institute for Environmental SciencesUniversity of New OrleansNew OrleansUSA
  2. 2.Department of Earth and Environmental Sciences and Pontchartrain Institute for Environmental SciencesUniversity of New OrleansNew OrleansUSA
  3. 3.Department of Earth SciencesBoston UniversityBostonUSA
  4. 4.U.S. Geological SurveySt. PetersburgUSA