On the Use of 210Pb-based Records of Sedimentation Rates and Activity Concentrations for Tracking Past Environmental Changes

Mapping Intimacies ◽

10.20944/preprints202201.0143.v1 ◽

2022 ◽

Author(s):

Jose María Abril

Keyword(s):

Environmental Changes ◽

Sediment Accumulation ◽

Model Errors ◽

Varved Sediments ◽

Activity Concentrations ◽

Virtual Laboratories ◽

Random Variability ◽

Recent Sediments ◽

Lead 210 ◽

True Values

Lead-210 from natural atmospheric fallout is widely used in multidisciplinary studies to date recent sediments. Some of the 210Pb-based dating models can produce historical records of sediment accumulation rates (SAR) and initial activity concentrations ( ). The former have been profusely used to track past changes in the sedimentary conditions. Both physical magnitudes are differently affected by model errors (those arising for the partial or null accomplishment of some model assumptions). This work is aimed at assessing the effects on SAR and of model errors in the CRS, CS, PLUM and TERESA dating models, due to random variability in 210Pb fluxes, which is a usual sedimentary condition. Synthetic cores are used as virtual laboratories for this goal. Independently of the model choice, SARs are largely affected by model errors, resulting in some large and spurious deviations from the true values. This questions their general use for tracking past environmental changes. are less sensitive to model errors and their trends of change with time may reflect real changes in sedimentary conditions, as it is shown with some real cores from varved sediments.

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Holocene sea level and climate interactions on wet dune slack evolution in SW Portugal: A model for future scenarios?

The Holocene ◽

10.1177/0959683618804633 ◽

2018 ◽

Vol 29 (1) ◽

pp. 26-44 ◽

Cited By ~ 2

Author(s):

Manel Leira ◽

Maria C Freitas ◽

Tania Ferreira ◽

Anabela Cruces ◽

Simon Connor ◽

...

Keyword(s):

Sea Level Rise ◽

Sea Level ◽

Environmental Changes ◽

Sediment Accumulation ◽

High Energy ◽

Sediment Supply ◽

Dune Slack ◽

Ecological Stability ◽

The Holocene ◽

Climate Interactions

We examine the Holocene environmental changes in a wet dune slack of the Portuguese coast, Poço do Barbarroxa de Baixo. Lithology, organic matter, biological proxies and high-resolution chronology provide estimations of sediment accumulation rates and changes in environmental conditions in relation to sea-level change and climate variability during the Holocene. Results show that the wet dune slack was formed 7.5 cal. ka BP, contemporaneous with the last stages of the rapid sea-level rise. This depositional environment formed under frequent freshwater flooding and water ponding that allowed the development and post-mortem accumulation of abundant plant remains. The wetland evolved into mostly palustrine conditions over the next 2000 years, until a phase of stabilization in relative sea-level rise, when sedimentation rates slowed down to 0.04 mm yr−1, between 5.3 and 2.5 cal. ka BP. Later, about 0.8 cal. ka BP, high-energy events, likely due to enhanced storminess and more frequent onshore winds, caused the collapse of the foredune above the wetlands’ seaward margin. The delicate balance between hydrology (controlled by sea-level rise and climate change), sediment supply and storminess modulates the habitat’s resilience and ecological stability. This underpins the relevance of integrating past records in coastal wet dune slacks management in a scenario of constant adaptation processes.

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Probability Spaces and the Theory of Error of Measurement

Psychological Reports ◽

10.2466/pr0.1971.28.1.291 ◽

1971 ◽

Vol 28 (1) ◽

pp. 291-301 ◽

Cited By ~ 2

Author(s):

Donald W. Zimmerman

Keyword(s):

Probability Model ◽

Random Variables ◽

Measurement Procedure ◽

Psychological Tests ◽

Random Variability ◽

Probability Spaces ◽

True Values ◽

Suitable Product ◽

Error Of Measurement

A model of variability in measurement, which is sufficiently general for a variety of applications and which includes the main content of traditional theories of error of measurement and psychological tests, can be derived from the axioms of probability, without introducing “true values” and “errors.” Beginning with probability spaces (Ω, P1) and (φ, P2), the set Ω representing the outcomes of a measurement procedure and the set * representing individuals or experimental objects, it is possible to construct suitable product probability spaces and collections of random variables which can yield all results needed to describe random variability and reliability. This paper attempts to fill gaps in the mathematical derivations in many classical theories and at the same time to overcome limitations in the language of “true values” and “errors” by presenting explicitly the essential constructions required for a general probability model.

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240+239Pu depositional signatures as a viable geochronological tool in the Amazon Basin

Geochronometria ◽

10.1515/geochr-2015-0068 ◽

2017 ◽

Vol 44 (1) ◽

pp. 142-149 ◽

Cited By ~ 1

Author(s):

Luciana M Sanders ◽

Kathryn H Taffs ◽

Debra Stokes ◽

Alex Enrich-Prast ◽

Christian J Sanders

Keyword(s):

Amazon Basin ◽

Environmental Science ◽

Sediment Cores ◽

Sediment Accumulation ◽

Recent Sediment ◽

Floodplain Lake ◽

Accumulation Rates ◽

Amazon Floodplain ◽

Dating Methods ◽

Lead 210

AbstractAnthropogenic radionuclide signatures associated with nuclear testing are increasingly utilized in environmental science to explore recent sedimentation. In this study, we assess the suitability of Pu radioisotope analysis in floodplain lake environments in the Amazon Basin to form geochronologies during the 20thcentury. The240Pu +239Pu (240+239Pu) signatures in six sediment cores indicate sediment accumulation rates in the floodplain lakes of the major rivers; Amazon (2.3 mm year-1), Tapajos (10.2 and 2.4 mm year-1) and Madeira (3.4, 4.2 and 6.2 mm year-1). The results from this study show that240+239Pu fallout activities, and the well documented (240Pu/239Pu) atomic ratios of the above ground nuclear tests which began in the 1950’s, are sufficient and well preserved in Amazon floodplain lake sediments to infer chronologies. Lead-210 dating analyses in the same sediment cores produced comparable sediment accumulation rates at three of the six sites. The differences between dating methods may be attributed to the different time scale these dating methods represent and/or in the solubility between Pb and Pu along the sediment column. The geochronologies derived from the240+239Pu and210Pb dating methods outlined in this work are of interest to identify the effects of changing sediment accumulation rates during the previous century as a result of development, including deforestation, along the Amazon Basin which increased towards the middle of the 20thcentury. This study shows that Pu dating provides a viable alternative geochronology tool for recent sediment accumulation (previous ~60 years) along the Amazon Basin.

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Stable Carbon and Oxygen Isotopes in Recent Sediments of Lake Wigry, NE Poland: Implications for Lake Morphometry and Environmental Changes

Stable Isotopes as Indicators of Ecological Change - Terrestrial Ecology ◽

10.1016/s1936-7961(07)01017-2 ◽

2007 ◽

pp. 267-281 ◽

Cited By ~ 1

Author(s):

Anna Paprocka

Keyword(s):

Oxygen Isotopes ◽

Environmental Changes ◽

Lake Morphometry ◽

Stable Carbon ◽

Carbon And Oxygen Isotopes ◽

Ne Poland ◽

Recent Sediments

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Measurement of Whole Lake Sediment Accumulation and Phosphorus Retention Using Lead-210 Dating

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f80-110 ◽

1980 ◽

Vol 37 (5) ◽

pp. 817-822 ◽

Cited By ~ 54

Author(s):

R. Douglas Evans ◽

Frank H. Rigler

Keyword(s):

Sediment Accumulation ◽

Lake Area ◽

Phosphorus Retention ◽

Sediment Retention ◽

Sample Depth ◽

Highly Correlated ◽

Lead 210 ◽

Mean Concentration ◽

Measured Input ◽

Rate Of Accumulation

Lead-210 dating was used to measure rates of sediment accumulation in 15 cores from Bob Lake, Ontario. The rate of accumulation was highly correlated with sample depth. This relation allowed the calculation of accumulation of sediments over the whole lake area. Phosphorus (P) retention was calculated from mean concentration of P in the sediments and the whole lake accumulation of sediment. Retention of P calculated in this way was similar to retention calculated from previously measured input and output of P.Key words: lead-210 dating, sediment accumulation, phosphorus retention

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Lead-210 chronology of the Scandinavian SWAP sites

Philosophical Transactions of the Royal Society of London Series B Biological Sciences ◽

10.1098/rstb.1990.0058 ◽

1990 ◽

Vol 327 (1240) ◽

pp. 239-242 ◽

Cited By ~ 2

Keyword(s):

Land Use ◽

Sediment Accumulation ◽

Past Century ◽

The Past ◽

Enhanced Dissolution ◽

Surface Water Acidification ◽

Constant Rate ◽

Minor Losses ◽

Lead 210 ◽

Atmospheric Inputs

In the Surface Water Acidification Project (SWAP) sediment profiles from five Scandinavian sites were analysed for 210 Pb by using refined isotope dilution alpha spectrometry. The 210 Pb parameters of these lakes were very similar to those obtained for protected forest lakes with no land-use activities. These data demonstrated almost exclusive atmospheric inputs and an internal deposition regulated by the organic fractionation and the grain-size distribution in the sediments. Preliminary speciation experiments showed minor losses of 210 (≤ 5%) through enhanced dissolution of fulvic compounds at acid conditions (pH ≥ 4). The sediment accumulation rates (constant rate of unsupported 210 Pb supply (CRS) model) of the lakes gradually increased, by at least a factor of three, over the past century although 210 Pb parameters did not show any strong signs of enhanced land-use activities. This is perhaps caused by more efficient preservation of the sediments through humic precipitation under more acid conditions.

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Holocene Environmental Changes in Western Hungary

Radiocarbon ◽

10.1017/s0033822200035748 ◽

2004 ◽

Vol 46 (2) ◽

pp. 691-699 ◽

Cited By ~ 6

Author(s):

Zsuzsanna Szántó ◽

Zsófia Medzihradszky

Keyword(s):

Bronze Age ◽

Environmental Changes ◽

Accumulation Rate ◽

Sediment Accumulation ◽

Anthropogenic Activity ◽

Late Neolithic ◽

Forest Clearing ◽

Plant Cultivation ◽

Radiocarbon Data ◽

Middle Bronze Age

We review the reasons for change in paleoecological conditions and their effects on different cultures at the beginning and during the Holocene period in western Hungary using radiocarbon data combined with paleoecological and paleolimnological results. Two sites were investigated in the southern and northern part of the ancient bay of Balaton Lake: Keszthely-Úsztatómajor and Főnyed I. 14C dating of 2 core samples represented a chronology from 11,000 cal BC to 2000 cal BC (10,700 BP to 3700 BP) and from 6200 cal BC to 1200 cal BC (7300 BP to 3000 BP), respectively. A relatively constant inverse sediment accumulation rate was observed in both cases (23 yr/cm and 33 yr/cm, respectively). In the case of Főnyed I, a sharp break was observed in the sedimentation curve around 6000–4800 cal BC (6000 BP). Changes in the vegetation due to human activity were observed in a larger extent only at the end of Late Neolithic, with the most significant changes detected in the landscape coinciding with the presence of Lengyel III culture in the region. The appearance of higher amounts of pollen of cereals at the sites proved the presence of crop cultivation. However, the role of plant cultivation may have been limited for the ancient inhabitants of the Kis-Balaton region due to a limited amount of soil suitable for agriculture and due to the extensive water table. Further changes in vegetation were observed during the Late Copper Age (Baden culture) and the period of Early and Middle Bronze Age, respectively. Signs of forest clearing during the period have not been detected and the increased peak of Fagus indicates climatic change. The low intensity of anthropogenic activity should not be attributed to geographic isolation.

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A Test of Lead-210 Dating for the Measurement of Whole Lake Soft Sediment Accumulation

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f83-069 ◽

1983 ◽

Vol 40 (4) ◽

pp. 506-515 ◽

Cited By ~ 35

Author(s):

R. Douglas Evans ◽

Frank H. Rigler

Keyword(s):

Lake Sediment ◽

Accumulation Rate ◽

Sediment Accumulation ◽

Soft Sediment ◽

Lake Morphometry ◽

Southern Ontario ◽

Lake Bottom ◽

Lead 210 ◽

Shield Lakes ◽

The Relationship

We have tested the hypothesis that variation in accumulation of soft sediments over a lake bottom is related to the lake morphometry, allowing an accurate measurement of whole lake sediment accumulation. In each of two Laurentian Shield lakes in southern Ontario, sediment accumulation was measured at ~20 locations. In both there was a statistically significant linear relationship between soft sediment accumulation and the water depth at the sample locations. The relationship explained 72 and 57% of sediment accumulation variation in Costello and Red Chalk lakes, respectively. Using these relationships, it was possible to calculate the whole lake sediment accumulation rate for each lake. The results indicate that, in general, there is a linear variation in sediment accumulation as a function of depth in small Shield lakes. This study points out the need for a closer examination of sediment movement and accumulation in the shallow regions of lakes.

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