Beryllium-7 Atmospheric Deposition And Sediment Inventories In The Neponset River Estuary, Massachusetts, Usa

摘要

Measured monthly atmospheric depositional fluxes of cosmogenically produced ~7Be ranged from 1 to 67 mBq/cm~2 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/cm~2. 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/cm~2 Comparisons of these sediment inventories with the ~7Be running inventory from atmospheric deposition (101 mBq/cm~2) 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.