2014 GSA Annual Meeting in Vancouver, British Columbia (19–22 October 2014)

Paper No. 311-11
Presentation Time: 11:30 AM

EXAMINING COASTAL MARSH ACCRETION AND DYNAMICS IN NORTHEASTERN, NC


STRAND, Jessica, Geological Sciences, East Carolina University, 101 Graham Building, Greenville, NC 27858, CORBETT, D. Reide, Integrated Coastal Programs, East Carolina University & UNC Coastal Studies Institute, Greenville, NC 27858 and WALSH, J.P., East Carolina University & UNC Coastal Studies Institute, Greenville, NC 27858

Coastal marshes are fragile environments that are ephemeral on geologic timescales. Understanding the dynamics that naturally maintain these systems is becoming increasingly important in the face of accelerated sea level rise, especially for North Carolina where 65% of its 19,826 km of estuarine shoreline is marsh. This study is focused on evaluating short-term (week/month) sediment accretion relative to decadal-scale accumulation and the possible source of that material at two marshes in northeastern North Carolina. To date, ceramic tiles have been placed at each study area. Monthly accretion has been monitored since January, 2014. A notable seasonal difference has been observed in rates of accretion, likely due to a change in the dominant wind direction (NE versus SW in the winter and summer, respectively). Sedimentological (i.e., grain size, LOI, etc.) and radiochemical (e.g., 210Pb and 137Cs) analysis are currently being performed on several short (~90cm) cores collected from each marsh to provide data on inter- and intra-site variability of sediment characteristics and rate of accumulation. Together, this data set will provide new information on marsh sediment dynamics in a rapidly changing environment.