The Geomorphology and Lithostratigraphy of Beach Ridges on the North Carolina Coastline

Posted July 13th, 2011 at 7:45 pm.

Abstract: Liz Newbern

Mentor: Donald Barber

Beach ridge formation is a process that is not as well understood as other geological systems. It has been a controversial issue in the scientific community. Part of the problem with understanding beach ridge formation is that the process involves many factors (i.e. wind strength, wave size, wave energy, tidal action, sediment composition, frequency of storms, and the underlying topography). Beach ridge formation cannot be assumed to be universally the same; different beaches produce different kinds of beach ridges. Since this is true, studying a particular set of beach ridges or singular ridge is not useful on a large scale, however it can be significant on a regional scale. The research conducted this summer will investigate a set of beach ridges in Cedar Island, North Carolina in order to come to a greater understanding of beach ridge formation processes in that region.

The research this summer will be overseen by Professor Donald Barber and done in conjunction with undergraduate student Anna Woodson. The research will include field and laboratory work in order to investigate the lithostratigraphy and geomorphology of the beach ridges and the coastline over the past 5,000 years. The field work will be conducted on Cedar Island in southern Pamlico Sound, North Carolina. It will involve using an auger to collect samples at predetermined locations along a series of beach ridges that are interspersed with salt marshes and mapping the shoreline and the topography of the ridges using laser theodolite (Total Survey Station) and several GPS systems. Once the field work is complete then the sediment cores will be transported back to Bryn Mawr College for analysis. The analysis will include visual logging and analyses of sediment particle size, magnetic susceptibility, organic carbon content, and radiocarbon dating of small plant fragments. The new data that is generated will be combined with existing data (from previously collected sediment cores and grab samples) will allow for the creation of a three dimensional model of the Holocene sediment deposits in the study area. This created model will help to reconstruct past environmental conditions of the beach ridges.

The goals of this project are: 1) to better understand beach ridge formation on a regional scale, 2) to come to a better understanding of the coastal geomorphology, and 3) to understand how coastal geomorphology is responding to changes in sea level. This will allow for better planning and aid for the future of coastal towns in a time when the sea level is rising.

These locations will be predetermined via visual evaluation using the program Google Earth.

Filed under: 2011,Barber, Dr. Don,Newbern, Liz by Michelle Han

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