Atmospheric deposition and soil vertical distribution of 7Be in a semiarid region of central Argentina

LOHAIZA, F.; VELASCO, R. H.; JURI AYUB, J.; RIZZOTTO, M.; VALLADARES, D. L.

Barcelona

Congreso; International conference on the radioecology and Environmental radioactivity; 2014

International Union of Radioecology

Beryllium-7 (Eγ = 477.6 keV, half-life of 53.3 days) is a potentially useful tracer of soil erosion due to single rain events and short periods of heavy rainfall. Additionally, Walling et al. (2009) have presented a new approach which provides a means of extending over several months the timeframe for using 7Be measurements to estimate soil redistribution magnitudes. The aim of the present research is to estimate the 7Be atmospheric wet deposition and 7Be inventory in undisturbed soils in a semiarid region of central Argentina and explore its seasonal variation. Poor information on 7Be atmospheric deposition and associated soil inventories in Argentina exists, particularly for the region that we are presenting here, for which we analyze the variability of 7Be content in rainwater and 7Be wet deposition. Using the 7Be monthly wet deposition the expected 7Be inventory in soil was estimated applying a simple iteration model, along an entire annual cycle (Juri Ayub et al., 2009). Finally, 7Be areal activity density along the soil profile was monthly measured (Lohaiza et al., 2013). Expected values for the 7Be content in soil obtained from the iteration models and measurements values were confronted and the differences are discussed.