Historical and Geographical Trends in Sediment Chronology from Lakes and Marine Sites Along the Norwegian Coast

• Published in: Water, air, and soil pollution air, and soil pollution, 2010-02, Vol.206 (1-4), p.237-250
• Main Authors: Larsen, Jorunn, Appleby, Peter G, Christensen, Guttorm N, Berg, Toril, Eide, Ingvar
• Format: Article
• Language: English
• Subjects: Animal, plant and microbial ecology; Applied ecology; Applied sciences; Atmospheric Protection/Air Quality Control/Air Pollution; Biological and medical sciences; Brackish; Chronologies; Climate Change/Climate Change Impacts; Coasts; Contaminated sediments; Continental surface waters; Cores; Earth and Environmental Science; Ecotoxicology, biological effects of pollution; Environment; Environmental monitoring; Exact sciences and technology; Fallout; Freshwater; Fundamental and applied biological sciences. Psychology; General aspects; geographical variation; history; Hydrocarbons; Hydrogeology; Inventories; Lake sediments; Lakes; Leaching; Lead; Marine; Marine accidents; Marine sediments; Natural water pollution; Nuclear power plants; Nuclear weapons; Pollution; Polycyclic aromatic hydrocarbons; Radioactive dating; Radioactive fallout; Radioisotopes; radionuclides; Seawater; sediment contamination; Sedimentation; Sedimentation & deposition; Sediments; Soil Science & Conservation; Soil testing; Statistical analysis; Trends; Water depth; Water Quality/Water Pollution; Water treatment and pollution
• ISSN: 0049-6979; 1573-2932
• DOI: 10.1007/s11270-009-0099-4

Sediment cores collected from 12 lakes and eight marine sites along the Norwegian and Svalbard coast as part of a project investigating polycyclic aromatic hydrocarbons (PAH) in sediments were dated radiometrically using ²¹⁰Pb, ¹³⁷Cs and ²⁴¹Am fallout radionuclides. In all lake cores, except on Svalbard, the ¹³⁷Cs activity versus depth profile appears to have been significantly modified by post-depositional migration within the sediment column. The relatively low ¹³⁷Cs inventories suggest that these sites were not significantly impacted by fallout from the 1986 Chernobyl accident. All the marine cores have ¹³⁷Cs inventories that are substantially lower than in lake sediments almost certainly due to leaching of ¹³⁷Cs from the marine sediments due to higher solubility in the seawater. In the marine surface sediments, the unsupported ²¹⁰Pb concentrations are up to an order of magnitude lower than in the corresponding lake sediments reflecting the higher (dry mass) sedimentation rate at the marine sites. Five of the cores including marine sites and lakes have unusual high ²¹⁰Pb flux most likely due to sediment focusing. Most of the irregularities in the ²¹⁰Pb records seem to be due to slump events but some patterns are also due to possibly increased accumulation rates. Three of the marine cores show systematic increase in their sedimentation rate from c.1960 towards the present while only one lake shows the same systematic increase.