Abstract
Photograph of Assateague Island back-barrier marsh with Chincoteague Bay in the background. Photograph courtesy of Alisha Ellis. [Click to enlarge] |
The effect of tropical and extratropical cyclones on coastal wetlands and marshes is highly variable and depends on a number of climatic, geologic, and physical variables. The impacts of storms can be either positive or negative with respect to the wetland and marsh ecosystems. Small to moderate amounts of inorganic sediment added to the marsh surface during storms or other events help to abate pressure from sea-level rise. However, if the volume of sediment is large and the resulting deposits are thick, the organic substrate may compact causing submergence and a loss in elevation. Similarly, thick deposits of coarse inorganic sediment may also alter the hydrology of the site and impede vegetative processes. Alternative impacts associated with storms include shoreline erosion at the marsh edge as well as potential emergence. Evaluating the outcome of these various responses and potential long-term implications is possible from a systematic assessment of both historical and recent event deposits. A study was conducted by the U.S. Geological Survey to assess the sedimentological and radiochemical characteristics of marsh deposits from Assateague Island and areas around Chincoteague Bay, Maryland and Virginia, following Hurricane Sandy in 2012. The objectives of this study were to (1) characterize the surficial sediment of the relict to recent washover fans and back-barrier marshes in the study area, and (2) characterize the sediment of six marsh cores from the back-barrier marshes and a single marsh island core near the mainland. These geologic data will be integrated with other remote sensing data collected along Assateague Island in Maryland and Virginia and assimilated into an assessment of coastal wetland response to storms. This report serves as an archive for sedimentological and radiochemical data derived from the surface sediments and marsh cores collected March 26–April 4, 2014. Select surficial data are available for the additional sampling periods October 21–30, 2014. Downloadable data are available as Excel spreadsheets and as JPEG files. Additional files include: Field documentation, x-radiographs, photographs, detailed results of sediment grain size analyses, and formal Federal Geographic Data Committee metadata (data downloads). |
Acknowledgments
This study was funded under the Disaster Relief Appropriations Act of 2013, supplemental funding from the U.S. Department of the Interior for projects that are part of the science plan “Meeting the Science Needs of the Nation in the Wake of Hurricane Sandy—A U.S. Geological Survey Science Plan for Support of Restoration and Recovery” (Buxton and others, 2013). The authors would like to thank Bill Hulslander and Neil Winn from the U.S. National Park Service, Kevin Holcomb from the U.S. Fish and Wildlife Service, Nicholas Nidezieko from Horn Point Marine Laboratory, and Ali Redman from Chincoteague Bay Field Station for logistical support, vessel operation, and facility use during field collection. We also appreciate the Web design assistance provided by Noreen Buster and Jolene Gittens of the U.S. Geological Survey (USGS). We would also like to thank Alexis Beudin and Kathryn Smith, also with the USGS, for their pre-release commentary and peer review.
Information Statement
Although these data have been processed successfully on a computer system at the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. The USGS or the U.S. Government shall not be held liable for improper or incorrect use of the data described and (or) contained herein. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
Suggested Citation
Smith, C.G., Marot, M.E., Ellis, A.M., Wheaton, C.J., Bernier, J.C., and Adams, C.S., 2015, Sedimentological and radiochemical characteristics of marsh deposits from Assateague Island and the adjacent vicinity, Maryland and Virginia, following Hurricane Sandy: U.S. Geological Survey Open-File Report 2015–1169, https://dx.doi.org/10.3133/ofr20151169.
Contact
Christopher G. Smith
Research Geologist
U.S. Geological Survey
St. Petersburg Coastal and Marine Science Center
600 4th Street South
St. Petersburg, FL 33701
(727) 502-8035
cgsmith@usgs.gov
