Christopher G. Smith Marci E. Marot Alisha M. Ellis Cathryn J. Wheaton Julie C. Bernier C. Scott Adams 20150501 tabular digital data U.S. Geological Survey Open-File Report 2015-1169 http://pubs.er.usgs.gov/publication/ofr20151169/data/14CTB_Alpha_Spec_Data.zip Christopher G. Smith Marci E. Marot Alisha M. Ellis Cathryn J. Wheaton Julie C. Bernier C. Scott Adams 20150501 1.0 multimedia presentation U.S. Geological Survey Open-File Report 2015-1169 St. Petersburg, Florida U.S. Geological Survey - St. Petersburg Coastal and Marine Science Center https://doi.org/10.3133/ofr20151169 The influence of tropical and extratropical cyclones on coastal wetlands and marshes is highly variable in both space and time and depends on a number of climatic, geologic, and physical variables. The impacts storms can be either positive or negative with respect to the wetland and marsh ecosystems. Small to moderate amounts of inorganic sediment added during storms or other events helps to abate pressure from sea-level rise. However, if the volume of sediment is large and the resulting deposits 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. Predicting the outcome of these various responses and potential long-term implications can be obtained from a systematic assessment of both historical and recent event deposits. The objectives of this study are to 1) characterize the surficial sediment of the relict to recent washover fans and back-barrier marshes, and 2) characterize the sediment of 6 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, Maryland / Virginia and assimilated into an assessment of coastal wetland response to storms. The 14CTB_Alpha_Spec_Data.zip file includes all alpha spectroscopy radiochemistry analysis results from the 8 marsh push cores and 1 auger core collected on Assateague Island and the mainland of Maryland and Virginia in March/April and October 2014 by the U.S. Geological Survey (USGS), St. Petersburg Coastal and Marine Science Center. This publication contains data for the field activities conducted in 2014: March 26 – April 4, 2014. 20140326 20140404 ground condition Complete None planned -75.46667 -75.11111 38.26667 37.82222 USGS Metadata Identifier USGS:6617e0e5-0ca6-467c-bdb8-47ad766b5836 None wetland sediment core radiochemistry alpha spectroscopy U.S. Geological Survey USGS U.S. Geological Survey St. Petersburg Coastal and Marine Science Center Geographic Names Information System (GNIS) Maryland Virginia Assateague Island None sediment subsurface None March 2014 April 2014 none U.S. Geological Survey - St. Petersburg Coastal and Marine Science Center Christopher G. Smith Research Geologist Mailing and physical

600 4th Street South

St. Petersburg FL 33701 US (727) 502-8035 cgsmith@usgs.gov U.S. Geological Survey Microsoft Windows Server 2008 R2 Version 6.1 (Build 7601) Service Pack 1; Microsoft Excel Version 2010 The U.S. Geological Survey requests that it be referenced as the originator of this dataset in any future products or research derived from these data. The radioisotopic activities reported in the Excel spreadsheets include the counting error for all samples. The data include core ID, sample depth interval in core (cm), total Pb-210 activity, and total Pb-210 counting error. This is a complete processed radiochemistry data file for USGS FAN 2014-301-FA (14CTB). At the USGS SPCMSC, the cores were extruded in 1-centimeter intervals and placed in labeled bags. The samples were refrigerated until further analysis. 20150501 U.S. Geological Survey St. Petersburg Coastal and Marine Science Center Christopher G. Smith Research Geologist Mailing and physical

600 4th Street South

St. Petersburg FL 33701 U.S. (727) 502-8035 cgsmith@usgs.gov Each subsample (approximately 20-30 mL of wet sediment) was oven-dried at 60°C for 48 hours. The dried sediment was homogenized to a fine powder using a porcelain mortar and pestle. Total Pb-210 (via granddaughter polonium-210; [Po-210]) were determined by alpha spectroscopy following the procedure of Marot and Smith (2012). Briefly, approximately 1 – 5 g of sediment was spiked with a 0.5 mL of Po-209 of known activity (12 decays per minute per milliliter [dpm mL-1]). Sediments were leached with a combination of concentrated nitric and hydrochloric acid with the addition of 30 % H2O2 to remove organics. Sediments were taken to near dryness and re-saturated three times with hydrochloric acid until all nitric acid is removed. Po-209 and Po-210 were electroplated onto silver planchets and counted on an alpha spectrometer. Count rate efficiency for Po-209 were determined and applied to Po-210 counts. Total Pb-210 is then assumed to be in secular equilibrium with Po-210 in the down-core sediment. 2014 U.S. Geological Survey St. Petersburg Coastal and Marine Science Center Christopher G. Smith Research Geologist Mailing and physical

600 4th Street South

St. Petersburg FL 33701 U.S. (727) 502-8035 cgsmith@usgs.gov Added keywords section with USGS persistent identifier as theme keyword. 20201013 U.S. Geological Survey VeeAnn A. Cross Marine Geologist Mailing and Physical

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Woods Hole MA 02543-1598 508-548-8700 x2251 508-457-2310 vatnipp@usgs.gov 14CTB Alpha Spec Data.xlsx Alpha spectroscopy radiochemistry results of sediment cores collected on Assateague Island, Maryland. USGS Core ID Marsh sediment core site number USGS Core site identification number assigned by USGS scientist Depth (cm) Sample interval depth measured from top of the core (cm) USGS 0-1 56-57 Total Pb-210 Activity (dpm/g) Total Pb-210 specific activity measured in disintegrations per minute per gram of dry sediment at the date of field collection. USGS 0.033 22.94 Total Pb-210 Activity Error (+/- dpm/g) Total Pb-2107 specific activity counting error measured in disintegrations per minute per gram of dry sediment at the date of field collection. USGS 0.004 0.555 U.S. Geological Survey St. Petersburg Coastal and Marine Science Center Christopher G. Smith Mailing and physical

600 4th Street South

St. Petersburg FL 33701 U.S. 502-8035 cgsmith@usgs.gov This publication was prepared by an agency of the United States Government. Although these data have been processed successfully on a computer system at the U.S. Geological Survey, no warranty expressed or implied is made regarding the display or utility of the data on any other system, nor shall the act of distribution imply any such warranty. The U.S. Geological Survey shall not be held liable for improper or incorrect use of the data described and (or) contained herein. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. none Zip archive 1 .zip 0.038 http://pubs.er.usgs.gov/publication/ofr20151169/data/14CTB_Alpha_Spec_Data.zip Downloadable data none These spreadsheets included in this .zip file were created for use with Microsoft Excel 2010. It may also be viewed with the Microsoft Excel viewer or by downloading a Microsoft Compatibility Pack to view with older versions of Microsoft Excel. The .zip file also contains comma delimited files (.csv) of the radiochemsitry data for each core. The .csv data files contains the tabular data in plain text and may be viewed with a standard text editor. 20201013 U.S. Geological Survey St. Petersburg Coastal and Marine Science Center Christopher G. Smith Research Geologist Mailing and physical

600 4th Street South

St. Petersburg FL 33701 U.S. (727) 502-8035 cgsmith@usgs.gov FGDC Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998 none None Unclassified None The U.S. Geological Survey requests that it be referenced as the originator of this dataset in any future products or research derived from these data.