The varved sediment profile of Lake Suigetsu, central Japan, offers an ideal opportunity from which to derive a terrestrial record of atmospheric radiocarbon across the entire range of the 14C dating method. Previous work by Kitagawa and van der Plicht (1998a,b, 2000) provided such a data set; however, problems with the varve-based age scale of their SG93 sediment core precluded the use of this...

Late Holocene paleoclimate records from coastal regions are important for understanding long-term variability of hurricane activity. Here we present a nearly 4000-year record of severe storm landfalls and environmental changes based on organic geochemical proxies (OGPs) preserved in sediment cores from two coastal lakes in northwest Florida. Our analysis shows that there are significant variati...

The relationships between long-term (;115-year) phosphorus and sediment accumulation and submerged macrophyte biomass were determined both within a submerged macrophyte bed and among beds in Lake Memphremagog, Quebec, Canada. Strong relationships between present submerged macrophyte biomass and littoral-zone sediment and phosphorus accumulation rates both within and among macrophyte beds yielde...

the behavior of suspended sediment during flood events is not only a function of energy conditions, i.e. sediment is stored at low flow and transported under high flow conditions, but also is related to the variations in sediment supply and sediment depletion. these changes in sediment availability result in so-called hysteresis effects. therefore, hysteresis pattern analysis is of great import...

Searles Lake is a salt-saturated, alkaline brine unusually rich in the toxic element arsenic. Arsenic speciation changed from arsenate [As(V)] to arsenite [As(III)] with sediment depth. Incubated anoxic sediment slurries displayed dissimilatory As(V)-reductase activity that was markedly stimulated by H2 or sulfide, whereas aerobic slurries had rapid As(III)-oxidase activity. An anaerobic, extre...

The biomass of sediment organisms can be measured by a.llowing carbon tracer to distribute itself through sediment cores. Application of this method to sediment from Marion lake, British Columbia, indicated that most of the sediment microorganisms were concentrated in the top 2 cm of sediment, where the total biomass of microorganisms was estimated to be 183IJ.g C/cm2• The radiotracer estimate ...

Lake systems are the largest integrated depositional complexes in the continental realm: modern lakes have areas up to 374,000 km2, and ancient lake strata extend up to 300,000 km2 in the Cretaceous systems of the south Atlantic and eastern China and the Permian system of western China. The largest lakes do not appear to form a significantly different population in many of their attributes. The...

Sediment cores were taken in 2002 in Lakes Ontario and Erie at four locations. A total of 48 sediment samples were characterized, dated using 210Pb, and analyzed for 10 congeners of polybrominated diphenyl ethers (PBDEs) including BDE209 as well as 39 congeners of polychlorinated biphenyls (PCBs). The surficial concentrations of nine tri- through hepta-BDE congeners (sigma9PBDE) are 4.85 and 6....

Layers of sediment that are deposited on the floor of Lake Ohau, New Zealand, offer a means to reconstruct past climate conditions in the Southern Hemisphere at subdecadal and annual resolution. A robust understanding of the modern physical processes that control the influx and dispersal of sediment in the lake is required to reconstruct climate from these sedimentary archives. In this study, w...

dianchi lake is one of the most three seriously eutrophic lakes in china. in the present study, the phosphorus (p) and nitrogen (n) fractions in 37 surface sediments samples collected in the dianchi lake were investigated. the total phophorus (tp) in sediments was divided into two parts: inorganic p (ip) and residual p (res-p). the results showed that the total phosphorus content in surface se...