scholarly journals Study on Vertical Profile of 210Pb and Sedimentation Rate at Pantai Remis Coastal Area and Kuala Selangor Estuary

2018 ◽  
Vol 7 (3.11) ◽  
pp. 202
Author(s):  
Umi Kalsum Abdul Karim ◽  
Ahmad Saat ◽  
Mohamed Izzharif Abdul Halim
Keyword(s):  
Sedimentation Rate ◽  
Coastal Area ◽  
Vertical Profile ◽  
Sediment Cores ◽  
210Pb Dating ◽  
Gravity Corer ◽  
210Pb Activity ◽  
Constant Rate ◽  
High Sedimentation ◽  
High Sediment

Two sediment cores in Kuala Selangor estuary and Pantai Remis coastal area were obtained using gravity corer and then were analyzed using Alpha Spectrometry System. In order to estimate the sedimentation rate in the area, 210Pb dating technique and Constant Rate & Supply (CRS) model were used. From the study, the vertical profile of 210Pb shows a decreasing trend with depth and finally achieving a constant level. Based on the vertical profile of 210Pb, activity of excess 210Pb was obtained and was used to determine the sedimentation rate in the study area. Pantai Remis coastal area shows high sedimentation rate than Kuala Selangor estuary which may due to high sediment input in the area. Besides, the differences in sedimentation rate might be attributed to highly variable sedimentary and hydrodynamic conditions in the estuary and coastal area.  

scholarly journals Paleośrodowiskowe znaczenie zmian tempa i charakteru sedymentacji osadów jeziora Jelonek w Borach Tucholskich = Paleoenvironmental significance of changes in the rate and type of sedimentation in Lake Jelonek within Poland’s Tuchola Pine Forest (Bory Tucholskie)

2020 ◽  
Vol 92 (3) ◽  
pp. 409-422
Author(s):  
Mateusz Kramkowski
Keyword(s):  
Sedimentation Rate ◽  
Sediment Cores ◽  
Rapid Change ◽  
Lacustrine Sediments ◽  
Younger Dryas ◽  
Pine Forest ◽  
Radiocarbon Dates ◽  
The Holocene ◽  
The North ◽  
High Sedimentation

This paper presents the matter of the environmental reconstruction of laminated lacustrine sediments from the Younger Dryas through to the present day, in particular in respect of microlithofacial analysis and sedimentation rate. Lake Jelonek is located within the Tuchola Pine Forest of northern Poland (at 53°45’58N, 18°23’30E). It occupies a subglacial channel immediately adjacent to the Wda Valley. The lake covers 19.9 ha and has a maximum depth of 13.8 m. In 2014, overlapping sediment cores JEL14 (14.23 m) were collected from that deepest part, in order for a full sediment profile including the younger Dryas and the Holocene to be created. Most of the sediment is found to be laminated. Sedimentation rate was reconstructed for the lake, along with microlithofacial variability of different sections of the sediment. The results obtained were related to an age depth model based on 14 AMS radiocarbon dates, varve chronology and the Askja AD 1875 cryptotephra; and was correlated with pollen profiles. The Holocene sediment record of Lake Jelonek exhibits differences between low and high sedimentation rate intervals and varved and non-varved intervals. From the beginning of the Holocene through to the Subatlantic period, sedimentation proved to be a stable phenomenon. However, in the Subatlantic period, the average sedimentation rate increased to 7.7 mm per year from 2.2 mm, with maximum rates even reaching 15.3 mm/year. This period is reflected in a lack of lamination and the appearance of redeposited deposits. These changes prove particularly sensitive to local impact, with distinct alternations of low and high sedimentation rates and varved and non-varved intervals. The most probable drivers for the observed variability reflect a combination of changes of climate plus anthropogenic deforestation during periods of settlement that enhanced the sensitivity of the lake to wind stress. A summary of all analyses allowed for the identification of periods of rapid change in sedimentation, and – indirectly – for the reproduction of changes in the water level and anthropopressure in and around Lake Jelonek. Such results contribute to a better understanding of local influences on fluctuations in lake sedimentation processes characteristic for the north of Poland, but also Central Europe more widely.

scholarly journals Sedimentation rates in the Lake Qattinah using 210Pb and 137Cs as geochronometer

2014 ◽  
Vol 41 (1) ◽  
pp. 81-86 ◽  
Author(s):  
Eskander Alhajji ◽  
Iyas Ismail ◽  
Mohammad Al-Masri ◽  
Nouman Salman ◽  
Mohammad Al-Haleem ◽  
...  
Keyword(s):  
Sediment Cores ◽  
Past Century ◽  
Sedimentation Rates ◽  
Accumulation Rates ◽  
210Pb And 137Cs ◽  
The Past ◽  
Activity Concentrations ◽  
210Pb Activity ◽  
Constant Rate ◽  
210Pb Method

Abstract The constant rate of supply (CRS) of excess 210Pb model was successfully applied to assess 210Pb data of two sediment cores from the lake Qattinah, Syria. Gamma spectrometry was used to determine 137Cs and 210Pb activity concentrations. The bottom of the cores was 210Pb-dated to years 1907 and 1893. The accumulation rates were determined using 210Pb method and found to vary similarly in both cores from 0.10 ± 0.01 to 3.78 ± 0.57 kg m−2 y−1 during the past century. 137Cs was used as an in-dependent chronometer. The two distinct peaks observed on the 137Cs record of both cores, corresponding to 1965 and 1986, have allowed a successful validation of the CRS model.

Modelling of 210Pb behaviour in the catchment and sediment of Lake Tali Karng, Victoria, and estimation of recent sedimentation rates.

1985 ◽  
Vol 36 (1) ◽  
pp. 15 ◽  
Author(s):  
JD Smith ◽  
TF Hamilton
Keyword(s):  
Lake Sediment ◽  
Sediment Core ◽  
Sedimentation Rate ◽  
Average Rate ◽  
210Pb Dating ◽  
Sedimentation Rates ◽  
Depth Profiles ◽  
Unsupported 210Pb ◽  
210Pb Activity ◽  
Over Time

The technique of 210Pb dating of sediments over time scales of up to 120 years is described and illustrated by a study of Lake Tali Karng. Results from the study of a sediment core from the deepest part of the lake shows that the flux of unsupported 210Pb to the sediment is about 145 mBq cm-2 year-1. Over the last 100 years, about 75 cm of sediment has accumulated at an average rate of 150-200 mg cm-2 year-1. Calculations using two models to convert 210Pb activity-depth profiles to age-depth profiles indicate that the sedimentation rate has increased slightly over the last 100 years. It is estimated that about 14% of the 210Pb falling in the catchment reaches the lake sediment, but depending on the assumptions made the possible range is 7-60%.

scholarly journals A STUDY OF THE FLOCCULS STRENGTH OF POLYDISPERSE COAL SUSPENSIONS TO MECHANICAL INFLUENCES

2017 ◽  
Vol 1 ◽  
pp. 13-20 ◽  
Author(s):  
Andrii Shkop ◽  
Musii Tseitlin ◽  
Oleksіi Shestopalov ◽  
Valentina Raiko
Keyword(s):  
Solid Fraction ◽  
Sedimentation Rate ◽  
Size Fraction ◽  
Residual Rate ◽  
Disperse Composition ◽  
Maximum Value ◽  
Solids Concentration ◽  
Constant Rate ◽  
High Sedimentation ◽  
Mechanical Influence

The effect of the concentration and disperse composition on the flocculation strength to mechanical influence is investigated. It is found that the residual rate of floccules sedimentation after the mechanical influence at a constant rate of flocculant has a maximum value at a concentration of solids in the slime in the range of 7-30 g/dm3. The best results are obtained in all the experiments at a solids concentration of 10 g/l. It is found that at a concentration up to 7 g/l and more than 30 g/l, the floccules is formed. They have the lowest residual rate after mechanical influences. With increasing content of the solid fraction of 40-100 microns over 15%, the strength of floccules increases. They retain their shape and relatively high sedimentation rate even after mechanical influence. The obtained data allow to recommend correction of the slime composition before flocculant injection both the concentration close to the optimum, and the content of size fraction of 40-100 mm more than 15 %.

An Assessment of Environmental Changes in Three Lakes from King's County (Nova Scotia, Canada) Using Diatom-Based Paleolimnological Techniques

2008 ◽  
Vol 43 (2-3) ◽  
pp. 85-98 ◽  
Author(s):  
Joshua R. Thienpont ◽  
Brian K. Ginn ◽  
Brian F. Cumming ◽  
John P. Smol
Keyword(s):  
Nova Scotia ◽  
Environmental Changes ◽  
Sediment Cores ◽  
Lake Management ◽  
River System ◽  
210Pb Dating ◽  
Hydroelectric Power ◽  
Diatom Assemblages ◽  
Shoreline Development ◽  
Before And After

Abstract Paleolimnological approaches using sedimentary diatom assemblages were used to assess water quality changes over the last approximately 200 years in three lakes from King's County, Nova Scotia. In particular, the role of recent shoreline development in accelerating eutrophication in these systems was assessed. Sediment cores collected from each lake were analyzed for their diatom assemblages at approximately 5-year intervals, as determined by 210Pb dating. Analyses showed that each system has changed, but tracked different ecosystem changes. Tupper and George lakes recorded shifts, which are likely primarily related to climatic warming, with diatom assemblages changing from a preindustrial dominance by Aulacoseira spp. to present-day dominance by Cyclotella stelligera. In addition to the recent climatic-related changes, further diatom changes in the Tupper Lake core between approximately 1820 and 1970 were coincident with watershed disturbances (farming, forestry, and construction of hydroelectric power infrastructure). Black River Lake has recorded an increase in diatom-inferred total phosphorus since about 1950, likely due to impoundment of the Black River system for hydroelectric generation and subsequent changes in land runoff. Before-and-after (i.e., top-bottom) sediment analyses of six other lakes from King's County provided further evidence that the region is being influenced by climatic change (decreases in Aulacoseira spp., increases in planktonic diatom taxa), as well as showing other environmental stressors (e.g., acidification). However, we recorded no marked increase in diatom-inferred nutrient levels coincident with shoreline cottage development in any of the nine study lakes. Paleolimnological studies such as these allow lake managers to place the current limnological conditions into a long-term context, and thereby provide important background data for effective lake management.

New Devonian microconchids (Tentaculita) from the Holy Cross Mountains, Poland

2011 ◽  
Vol 85 (4) ◽  
pp. 757-769 ◽  
Author(s):  
Michał Zatoń ◽  
Wojciech Krawczyński
Keyword(s):  
Sedimentation Rate ◽  
Distal Portion ◽  
Taxonomic Composition ◽  
Soft Bottom ◽  
Holy Cross Mountains ◽  
Competition For Space ◽  
High Sedimentation ◽  
New Material ◽  
Three New Species ◽  
Hard Substrates

Tentaculitoid microconchid tubeworms from Devonian (uppermost Emsian-upper Givetian) deposits of the Holy Cross Mountains, Poland, include three new species from stratigraphically well-constrained lithological units:Polonoconchus skalensisn. gen. n. sp.,Palaeoconchus sanctacrucensisn. sp. andMicroconchus vinnin. sp. The microconchids inhabited fully marine environments during transgressive pulses, as is evidenced from facies and associated fossils.Polonoconchus skalensisn. gen. n. sp. andPalaeoconchus sanctacrucensisn. sp. inhabited secondary firm- to hard-substrates in deeper-water, soft-bottom environments. They developed planispiral, completely substrate-cemented tubes and planispiral tubes with elevated apertures, which is indicative of environments where sedimentation rate is low but competition for space (by overgrowth) may be high.Microconchus vinnin. sp., on the other hand, developed a helically coiled distal portion of the tube as a response to a high sedimentation rate. As the taxonomic composition of Devonian microconchids is poorly recognized at both regional and global scales, this new material contributes significantly to our understanding of the diversity of these extinct tube-dwelling encrusters.

The determination of sedimentation rates in Lake Ontario using the 210Pb dating method

1978 ◽  
Vol 15 (3) ◽  
pp. 431-437 ◽  
Author(s):  
John G. Farmer
Keyword(s):  
Sedimentation Rate ◽  
Lake Ontario ◽  
Sedimentary Basins ◽  
210Pb Dating ◽  
Sedimentation Rates ◽  
Surface Mixing ◽  
Dating Method ◽  
210Pb Dating Method

The 210Pb dating method has been applied successfully to the determination of recent sedimentation rates at four sites distributed among the three major sedimentary basins (Niagara, Mississauga and Rochester) of Lake Ontario. Following correction for effects due to compaction of the sediments, mean sedimentation rates ranging from 0.02 cm/year at the periphery of the Mississauga basin to 0.11 cm/year in the Niagara and Rochester basins were determined. Allowance for compaction reduced the non-compaction-corrected sedimentation rates by 20–35%. Neither 210Pb nor fallout 137Cs profiles indicated surface mixing of sediment sufficient to noticeably affect the calculated sedimentation rates. At all four sites, the sedimentation rate seems to have remained constant during the last 100–150 years.

scholarly journals Ventilation changes in the western North Pacific since the last glacial period

2011 ◽  
Vol 7 (4) ◽  
pp. 2719-2739 ◽  
Author(s):  
Y. Okazaki ◽  
T. Sagawa ◽  
H. Asahi ◽  
K. Horikawa ◽  
J. Onodera
Keyword(s):  
Sedimentation Rate ◽  
North Pacific ◽  
Western North Pacific ◽  
Glacial Period ◽  
High Quality ◽  
Last Glacial Period ◽  
The Past ◽  
High Sedimentation ◽  
The Last Glacial

Abstract. We reconstructed the ventilation record of deep water at 2100 m depth in the mid-latitude western North Pacific over the past 25 kyr from radiocarbon measurements of coexisting planktic and benthic foraminiferal shells in sediment with a high sedimentation rate. The 14C data on fragile and robust planktic foraminiferal shells were concordant with each other, ensuring high quality of the reconstructed ventilation record. The radiocarbon activity changes were consistent with the atmospheric record, suggesting that no massive mixing of old carbon from the abyssal reservoir occurred throughout the glacial to deglacial periods.

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