Late Holocene barrier island collapse: Outer Banks, North Carolina, USA

Stephen J Culver,Candace A Grand Pre,Jeb Rosenberger,Scott W Snyder,Michael Hale,Curtis W Smith,Lauren Metger,Stanley R Riggs,D Reide Corbett,Benjamin Horton,Kathleen Farrell,David Twamley,Christopher G Smith,David J Mallinson,Jennifer Foley,John Ricardo,David Furbish,Steven Goodbred,Molly Miller

doi:10.2110/sedred.2007.4.4

Abstract

We document here the threat of large scale destruction (collapse) of barrier islands based on the study of many cores taken along the Outer Banks and in Pamlico Sound, North Carolina. Around 1,100 cal yr BP, probably as the result of hurricane activity, portions of the southern Outer Banks must have collapsed to allow normal salinity waters to bathe southern Pamlico Sound for several hundred years. Such collapse could occur again during our current regime of global warming, rising sea level and increased tropical cyclone activity. The economic effect of barrier island break collapse on Outer Banks communities would be devastating.

Highlights

Large-scale destruction by recent hurricanes of Gulf Coast barrier islands, extending from Santa Rosa Island in the Florida Panhandle to the Chandaleur Isles in Louisiana, demonstrates their ephemeral nature
We have used foraminiferal assemblages collected from vibracores taken on and behind the barrier islands, to investigate the stability and longevity of the Outer Banks, North Carolina (Fig. 1)
The unexpected presence of subtropical to tropical planktonic foraminifera and in situ normal salinity neritic benthic foraminiferal assemblages in this and at least three adjacent cores suggests that large portions of the southern Outer Banks collapsed approximately 1,100 cal yr BP, allowing normal salinity, shelf waters to enter the Pamlico basin

Summary

Introduction

Large-scale destruction by recent hurricanes of Gulf Coast barrier islands, extending from Santa Rosa Island in the Florida Panhandle to the Chandaleur Isles in Louisiana, demonstrates their ephemeral nature. The unexpected presence of subtropical to tropical planktonic foraminifera and in situ normal salinity neritic benthic foraminiferal assemblages in this and at least three adjacent cores suggests that large portions of the southern Outer Banks collapsed approximately 1,100 cal yr BP, allowing normal salinity, shelf waters to enter the Pamlico basin.

Results

Conclusion