Sediment core collection

Figure 7. Excess activity versus depth (left) and X-radiograph (right) in a sediment core collected from the New York Bight, showing the importance of mixing by benthic fauna in the upper part of the seabed. Abundant individnals of the small bivalve Nucula proximo may be seen in the X-radiograph near the sediment-water interface, and the light-colored areas represent bnrrows of Nephtys sp. and Ceriantheopsis sp. Reprinted from Estuarine Coastal and Shelf Science (formerly Estuarine and Coastal Marine Science) Vol. 9, Cochran and Aller, pp. 739-747, 1979, with permission from Elsevier Science.

Walker et al. [17] studied profiles of hydrocarbons in sediment according to depth in sediment cores collected at Baltimore Harbour in Chesapeake... 

Walker et al. [17] studied profiles of hydrocarbons in sediment according to depth in sediment cores collected at Baltimore Harbour in Chesapeake Bay, Massachusetts. Gas liquid chromatography was used to detect hydrocarbons present at different depths in the sediment, while low resolution mass spectrometry was employed to measure concentrations of paraffins, cycloparaffins, aromatics and polynuclear aromatics. Their data show that the concentrations of total and saturated hydrocarbons decreased with increased depth, and it is commented that identification and quantitation of hydrocarbons in oil-contaminated sediments is required if the fate of these compounds in dredge spoils is to be determined. 

Fig. 12.6 Bar graph of acid volatile sulphide in a sediment core collected from Blelham Tarn on 30 July 1980 Rowlatt s mean data forthe sediments of this lake (distillat-ion/iodometric procedure) [110]...

For Cedar and Mountain lakes, detailed sediment cores collected from the deeper regions of each basin showed increasing sedimentation rates up-core. Thus a slightly different approach was used to provide additional temporal detail from the coarsely sectioned cores. These subsequent cores were extruded into five intervals 5-20 cm long so that dates and sediment accumulation rates could be explicitly calculated for the deeper strata. 

Fig. 8 PCBs in a sediment core collected in Grand Traverse Bay, Lake Michigan (modified from [210] and PCB production data [3])...

Okumura, Y., Yamashita, Y., Kohno, Y., Nagasaka, H., 2004. Trends of PCDD/Fs and co-PCBs in a sediment core collected in Sendai Bay, Japan. Water Res. 38, 3511-3522. 

Figure 7.20 A dual-tracer approach (using both 137Cs and 210Pb) in sediment cores collected from lower Chesapeake Bay (USA). The maximum depth of 137Cs was used to corroborate the physical mixing depths established with excess 210Pb. = excess activity A = total activity. (Modified from Dellapenna et al., 1998.)...

Figu re 7.28 <534S values of different sulfur species [disulfide sulfur (DS), acid-volatile sulfur (AVS), and organic sulfur (OS)] in sediment cores collected from the Everglades, south Florida (USA). (Modified from Bates et al., 1998.)... 

Arsenic was distributed among the operationally defined fractions of the sediment solids of a sediment core collected in September, 1977 as shown in Figure 3. Generally, the order of abundance of As in the fractions was OH" (Fe and Al) > oxalate (amorphous or occluded) Cl" (exchangeable) ... 

Comparative elemental analyses of the upper and lower sections of two sediment cores collected on the MAP show that organic concentrations decreased at both locations from values of 0.93-1.02 wt.% OC below the oxidation front to values 0.16-0.21 wt.% within the surface-oxidized layer (Figure 9). Pollen abundances decreased in the same samples from —1,600 grains g below the oxidation front to zero above it. Overall, 80% of the organic matter and essentially all of the pollen that has been stable for 140 kyr in the presence of pore-water sulfate was degraded in the upper section of the MAP cores as a result of long-term exposure to dissolved O2. 

In an attempt to assess the quantitative contribution of reactive processes to the overall cycling of anthropogenic source contamination, two examples will be considered (i) vinyl chloride oxidation at groundwater-surface water interface (GSI) St. Joseph, Michigan (e.g., Lendvay et al., 1998a,b), and (ii) dioxin dechlorination in estuarine sediment cores collected from the Passaic River, New Jersey... 

Sediment core collected in Buzzards Bay, Mass. 5/24/72 water depth, 16 m location of sediment section in core, 4-6 cm. 

Table VI shows the distribution of Pu, Tu, 239,24op j d within a sediment core collected several hundred miles northwest of the British Isles. Concentration profiles of plutonium and americium nuclides are rather similar in shape. The transuranic concentrations found in this sediment were surprisingly high. The high concentrations are believed to result from deposition of these nuclides from advected water carrying these nuclides from another area, rather than from the direct vertical transport of sinking particles.

The combustion source hypothesis was tested to ascertain the behaviour of hydrocarbons in sediments from a remote sub-antarctic island (King Edward Cove) (49). This site was an important seal hunting ground for decades early in the nineteenth century and then hosted a whale processing factory which closed in 1965. These activities led to significant contamination of the bay with fossil fuel and organic material. Marine sediment cores collected at a depth of 18 m clearly reflect the cessation of industrial operations, while further research is necessary for a better understanding of the fate of petroleum components in cold benthic ecosystems. 

Figure 7. Estimated contributions of erosion and atmospheric fallout to the sedimentation of Cs in the bottom sediment of Lake Shinji compared with observed sedimentation rate (solid line) based on the measured amount of Cs in a sediment core collected in 1994.

FIGURE 16.8 Effects of flooding and draining cycles on nitrous oxide emission from sediment cores collected from the salt marsh. (Modified from Smith et al., 1983.)... 

Sediment core collection and extension. John R. Glew, John P. Smol William M. Last... 

Fig. 6. (a) Vertical concentration profile of total organic carbon (TOC) in sediment core collected from station 3C in 1981 and (b) historical emissions (mta = metric tons yr ) of suspended solids from the LACSD wastewater outfall system, 1946-1981 (modified from Eganhouse and Pontolillo, 2000). 

Fig. 7. Vertical concentration profiles of molecular markers (6-C12 (6-phenyldodecane), TAB3 (a tetrapropylene-based alkylbenzene) and p,p -DDE) in sediment cores collected from the Palos Verdes Shelf in (a) 1981 (station 3C) and (b) 1992 (station 522) and age-dates assigned based on historical discharge/usage patterns (modified from Eganhouse and Pontolillo, 2000). Location of sediment coring stations is shown in Fig. 5.

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