| Popis: |
Concentrations of anthropogenic radionuclides ( 137 Cs, 239, 240 Pu and 241 Am) were measured in surface seawater, water column and sediment samples collected in Moroccan coastal waters. The average activity concentrations in surface water were 2.7 mBq L −1 , 8.7 μBq L −1 and 1.5 μBq L −1 for 137 Cs, 239, 240 Pu and 241 Am, respectively. The vertical distributions of 239,240 Pu in the water column of the southwest Mediterranean showed a sub-surface maximum at 500 m water depth, while 137 Cs concentrations were constant up to 900 m. On the contrary to the 239,240 Pu profile, which has been as expected, the 137 Cs profile has been affected by movement of water masses in the western Alboran Sea. The total inventories of 137 Cs and 239,240 Pu in the water column (0–900 m) were estimated to be 2170 and 23 Bq m −2 , respectively, and they were as expected for this water depth. The concentration profiles of 137 Cs and 239,240 Pu in the sediment core revealed the presence of sub-surface maximum located at the depth of 5 cm. The sedimentation rate of 0.12 cm yr −1 has been estimated using the 210 Pb profile, which indicated that the observed peaks of 137 Cs and 239,240 Pu originated in the sediment core following the maximum global fallout deposition in 1963. |
