Beryllium-7 atmospheric deposition and sediment inventories in the Neponset River estuary, Massachusetts, USA

Measured monthly atmospheric depositional fluxes of cosmogenically produced 7Be ranged from 1 to 67 mBq/cm2 in Boston, Massachusetts between September 2000 and August 2007. These fluxes exhibited seasonality and supported a decay-corrected 7Be atmospheric depositional running inventory that ranged from 36 to 144 mBq/cm2. Annual 7Be deposition exhibited an increasing trend that may reflect a general decrease in solar activity and a general increase in precipitation over the 7-year sampling period. To investigate short-term sediment dynamics and accumulation patterns in the Neponset River estuary, we collected six sediment cores in July 2006 and measured 7Be sediment inventories ranging from 48 to 546 mBq/cm2 Comparisons of these sediment inventories with the 7Be running inventory from atmospheric deposition (101 mBq/cm2) at the time of core collection indicated a large degree of spatial heterogeneity in sediment accumulation patterns and its potential use as a tool for assessing the impacts of environmental restoration activities in estuarine environments.