Subtask 2.2: Geologic Framework and Holocene Coastal Evolution – Mississippi-Alabama Region

Subtask Leader: James Flocks - USGS Florida Integrated Science Center, St. Petersburg

Coastal features evolve along the northern Gulf of Mexico (NGOM) coast as shallow (<100 meter) stratigraphy and topography interact with modern processes such as sea-level and sediment supply changes and climatic variability. By characterizing the geologic framework and surface characteristics of the coastal area, we can understand the variable response of the NGOM coast to natural and human-related mechanisms.

Satellite image of the Gulf Coast region along the Mississippi and Alabama coast after landfall of Hurricane Katrina. The image is enhanced to show coastal flooding (dark colors).  The barrier islands sustained significant erosion during the storm. The Chandeleur Island chain in the center of the image was severely eroded by the storm and is barely visible. Knowledge of the geologic framework in this region helps scientists understand how the shorelines will respond to future impacts from storms like Hurricane Katrina. Image taken September 15, 2006 by NASA's Terra satellite. [enlargement]

The geomorphology of the northern Gulf of Mexico (NGOM) coastal zone is a complex arrangement of landscapes produced by fluvial processes and sea level rise over the past 7000 years.

This subtask addresses the inner shelf offshore of the Mississippi and Alabama coastline, to develop a geologic framework for the region through the synthesis of existing knowledge and integration with new research. The goal is to provide a comprehensive understanding of the geology and its role in the coastal evolution of the region.

Subtask 2.2 Activities:

The goal of this subtask is to map the late Holocene stratigraphy of the inner shelf and coastal region offshore of Mississippi and Alabama.

The specific objectives are to:

• Define the Holocene facies underlying Mississippi Sound and offshore of the Gulf Coast islands; and

• Improve our understanding of the platform on which these islands are built.