Marsh vertical accretion, sediment grain size, and Be-7 activity in Coos Bay (Oregon, USA) from 20110101 to 20220330 (NCEI Accession 0291012)

Sediment cores were collected approximately monthly at six locations in tide flats across the Coos estuary (Oregon, USA). Between January 2021 and March 2022, 4 to 11 cores were taken at each site. Cores were collected using a ~15 cm length of aluminum pipe (~10 cm diameter) that was pushed into the tide flat and dug out with a trowel. Cores were then extruded into 1-cm increments and analyzed for grain-size distribution and Be-7 activity on select intervals.

Between 2011 and 2022, feldspar marker horizons were established at study sites in high and low marshes by placing a thick layer of powdered feldspar onto the marsh surface. Each study site includes three feldspar plots. Approximately annually after plot establishment, small square cores were cut out of the marsh within each feldspar plot using a serrated knife. The distance from the marsh surface to the top of the feldspar layer was measured on all four sides of the core. This process was repeated for each of the three feldspar plots per study site. All 12 measurements (3 cores x 4 sides per core) were averaged to produce a single vertical accretion value per site. Study sites with at least five measurements of vertical accretion in the 5-12 years following feldspar marker horizon plot installation were used to calculate mean vertical accretion rate (linear best-fit).

The files provided include one csv of marker horizon metadata (latitude, longitude, wetland type, plot installation date) and mean vertical accretion rate; one csv of marker horizon data (sample date, surface height above marker horizon); one csv of median grain size; and one csv of Be-7 activity.