On the basis of the congener-specific analysis of dioxins in a dated sediment core, surface sediment, and soil samples, the sources and mass balance of dioxins in Tokyo Bay basin, Japan, were estimated. The dioxins in the sediment core showed that their deposition in the bay increased rapidly during the 1960s, peaked in the early 1970s and then decreased gradually. Principal component analysis ...

sediment core samples can provide useful information about aquatic environment. sedimentation rate, climate changes and heavy metal concentration are among the most important studies that are carried out on sediment cores. in this study, a sediment core of 70cm with aim of metal concentration investigation is collected from central part of the zarivar lake in the vicinity of the marivan city in...

A methodology is proposed for grading the utility of lake sediment cores used to reconstruct pollution histories. The observed distribution of 13’Cs with depth in the core is compared to that expected from independent, historic measurements of fallout deposition. The width of the 13’Cs peak in the core profile that corresponds to the fallout maximum of 1963, or the combined maxima of 1959 and 1...

a r t i c l e i n f o The cosmogenic radionuclide 10 Be was measured from drill core sediments from Lake Malawi in order to help construct a chronology for the study of the tropical paleoclimate in East Africa. Sediment samples were taken every 10 m from the core MAL05-1C to 80 m in depth and then from that depth in core MAL05-1B to 382 m. Sediment samples were then later taken at a higher reso...

In situ video observations and sediment core samplings were performed at two hadal sites in the Japan Trench on July, 2011, four months after the Tohoku-Oki earthquake. Video recordings documented dense nepheloid layers extending ~30-50 m above the sea bed. At the trench axis, benthic macrofauna was absent and dead organisms along with turbid downslope current were observed. The top 31 cm of se...

A highly chlorinated flame retardant, Dechlorane Plus (DP), was detected and identified in ambient air, fish, and sediment samples from the Great Lakes region. The identity of this compound was confirmed by comparing its gas chromatographic retention times and mass spectra with those of authentic material. This compound exists as two gas chromatographically separable stereoisomers (syn and anti...

We studied a complete Holocene sediment record from shallow (zmax = 9.7 m) Lake Harris, Florida (USA) to infer the historical development of the lake and its current eutrophic status. We used (210)Pb and (14)C to date the 5.9-m sediment sequence (core LH-6-13) and determined accumulation rates for bulk sediment, organic matter, calcium carbonate, phosphorus fractions and biogenic silica fractio...

Bacterial transport through cores of intact, glacial-outwash aquifer sediment was investigated with the overall goal of better understanding bacterial transport and developing a predictive capability based on the sediment characteristics. Variability was great among the cores. Normalized maximum bacterial-effluent concentrations ranged from 5.4x10(-7) to 0.36 and effluent recovery ranged from 2...

The remediation of toxic sediment in harbours and urban waterways requires detailed mapping of contaminated sediment distribution and thickness. Conventional methods rely on interpolation of pollutant concentrations from widely spaced core samples but can lead to significant errors in estimating sediment distribution. An improved approach, as demonstrated by recent work in Hamilton Harbour in L...

A multi-proxy approach was used to examine the geomorphic dynamics and environmental history of an upper deltaic floodplain tract in the Sacramento–San Joaquin Delta, California. Three long cores were collected from the McCormack– Williamson Tract (MWT) and these cores were analyzed for bulk density, loss-on-ignition, fine (clay and silt) content, Al concentration, magnetic susceptibility, poll...