1 Subsidence, Accretion: Coastal Depletion?

Monday, 21 March 2016
8:00 AM - 12:00 PM
Governor Room

CAUSES OF ACCELERATED LAND LOSS IN COASTAL LOUISIANA

Paper number: 1-4
Program: Theme Sessions
Time: 9:00 AM – 9:20 AM

Authors

Abstract

Kolker et al. (2011) found a tight coupling between patterns of land loss measured in the Barataria Basin by Couvillion et al. (2011) and their interpretation of subsidence from the historical record of the Grand Isle tidal gauge. The relationship between subsidence and land loss in the temporal domain determined by Kolker et al. (2011) can be extended to the spatial domain using the Land Area Change Map produced by Couvillion et al. (2011). Extrapolating from the tightly bound relationship between temporal patterns of land loss and the measurement of subsidence in the Barataria Basin across the SE Louisiana coastal plain provides a first order approximation of a subsidence map. This map is integrated with a first order approximation of the traces of active faults across the surface of the coastal plain to yield a pattern of hot spots of subsidence caused by the vertical movement of faults. This pattern of hot spot subsidence (and land loss) is integrated with a map of the distributary channels of the lower Mississippi River system that were likely to have been active between the late 18th and early 20th centuries to suggest that sedimentary loading during the period of elevated suspended load of the river system (Tweel and Turner, 2012) may have triggered a period of fault movement that is responsible for the mid to late 20ths century period of accelerated land loss on the coastal plain.

Geological Society of America Abstracts with Programs. Vol. 48, No. 1

doi: 10.1130/abs/2016SC-271529

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