Miner, M. D., University of New Orleans, Pon, New Orleans, USA, mminer@uno.edu
Kulp, M. A., University of New Orleans, Department of Earth and Environmental Sciences, New Orleans, USA, mkulp@uno.edu
Georgiou, I. Y., University of New Orleans, Pontchartrain Institute for Environmental Sciences, New Orleans, USA, igeorgiou@uno.edu
Sallenger, A. H., USGS Center for Coastal and Watershed Studies, St. Petersburg, USA, asallenger@usgs.gov
FitzGerald, D. M., Boston University, Department of Earth Sciences, Boston, USA, dunc@bu.edu
Flocks, J. G., USGS Center for Coastal and Watershed Studies, St. Petersburg, USA, jflocks@usgs.gov
Twichell, D. C., USGS , Woods Hole, USA, dtwichell@usgs.gov

SEDIMENT TRANSPORT TRENDS ALONG THE CHANDELEUR ISLANDS, LOUISIANA: IMPLICATIONS FOR ISLAND SUSTAINABILITY AND BARRIER ISLAND MANAGEMENT

Bathymetric analyses (1880-2006) for the Chandeleur Islands reveal long-term trends of barrier extension and retreat and recently, barrier disintegration, shoreface erosion (vertically 1-2 m), and mixed erosion and accretion on the backbarrier platform (0-4 m). Volume calculations indicate ≈150x106 m3 of sediment has been deposited downdrift (northward) and seaward of the northern terminal spit, whereas the southern end of the barrier has undergone long-term erosion. Bathymetric and shoreline analyses suggest that the islands are impacted primarily during major hurricanes, resulting in shoreline retreat in some sectors and shoal development and in-place drowning in others. Katrina removed >90% of sand comprising the barriers exposing backbarrier marshes to wave attack. During the following year, >50% of the length of the northern Chandeleurs shoreline continued to erode (>200 m). However, during year two of recovery, marsh islands served as nucleation sites for sand accumulation along the northern arc. Incipient barrier islands now protect marshes. Contrastingly, southern segments of the chain, where marsh islands were absent, have undergone transgressive submergence. Downdrift sand reservoirs may provide a quasi-renewable resource for nourishing the updrift barrier system.

Oral presentation

Presentation is given by student: No
Session #:078
Date: 03-06-2008
Time: 16:45

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