Shoreline for the Timbalier Islands, 1887

The U.S. Geological Survey (USGS), in cooperation with the Coastal Research Laboratory in the Department of Geology and Geophysics at the University of New Orleans (UNO) and the Center for Coastal Energy and Environmental Resources at Louisiana State University (LSU), is investigating the processes of coastal erosion and wetland loss in Louisiana (Sallenger and others, 1987; Sallenger and Williams 1989; Penland and others, 1992).
Building on the USGS Louisiana Barrier Island Study (Williams and others, 1992), this data layer depicts the shoreline as it stood in 1887.
The Timbalier Islands are located about 100 km south-southwest of New Orleans. This barrier island shoreline is 30 km long and extends east from Cat Island Pass to Raccoon Pass. The Timbalier Islands represent a flanking barrier island system developed from the reworking and erosion of an abandoned distributary of the Lafourche delta complex within the Mississippi River delta plain (Penland and others, 1988). Island evolution is driven by predominant longshore sediment transport and storm overwash, causing the island arc to migrate to the north and west. The present configuration of the Timbalier Islands consists of Timbalier Island to the west, Timbalier Shoal, and East Timbalier Island to the east. Timbalier Shoal, located between the two islands within Little Pass Timbalier, is a transient area of moving sand, which is subaerial for some periods of measurement. The Gulf shoreline of East Timbalier Island has been armored by a rock seawall with a second seawall constructed landward in an attempt to protect oil and gas facilities on the bayside.
In order to quantify shoreline changes since January 21, 1988, new vertical aerial mapping photography was acquired on December 9, 1996 The methods and transects used by McBride and others (1992) were used to insure data compatibility of the new measurements and analysis