Assessing the Evolution of Dissolved Inorganic Carbon and Stable Carbon Isotopes in Surface Waters

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Total Pages : 134 pages
Book Rating : 4.:/5 (932 download)

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Book Synopsis Assessing the Evolution of Dissolved Inorganic Carbon and Stable Carbon Isotopes in Surface Waters by : Pride Tamasang Abongwa

Download or read book Assessing the Evolution of Dissolved Inorganic Carbon and Stable Carbon Isotopes in Surface Waters written by Pride Tamasang Abongwa and published by . This book was released on 2014 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Predicting Stable Isotope Signatures of Dissolved Inorganic Carbon in Lakes

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ISBN 13 :
Total Pages : 112 pages
Book Rating : 4.:/5 (89 download)

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Book Synopsis Predicting Stable Isotope Signatures of Dissolved Inorganic Carbon in Lakes by : Darren Lee Bade

Download or read book Predicting Stable Isotope Signatures of Dissolved Inorganic Carbon in Lakes written by Darren Lee Bade and published by . This book was released on 2002 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Assessing the Conserved Behavior of Dissolved Organic Carbon in the Deep Ocean

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ISBN 13 :
Total Pages : pages
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Book Synopsis Assessing the Conserved Behavior of Dissolved Organic Carbon in the Deep Ocean by : Sarah K Bercovici

Download or read book Assessing the Conserved Behavior of Dissolved Organic Carbon in the Deep Ocean written by Sarah K Bercovici and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The global ocean contains a massive reservoir (662±32 Pg C) of dissolved organic carbon (DOC), and its dynamics, particularly in the deepest zones, are only slowly being understood. DOC in the deep ocean is ubiquitously low in concentration (~35 to 48 [mu]mol kg-1) and aged (4000 to 6000 years), persisting for multiple meridional overturning circulation cycles. Deep waters relatively enriched in DOC form in the North Atlantic. They migrate to the Southern Ocean (SO) to mix with waters from Antarctic shelves and the deep Pacific and Indian Oceans, in turn forming the voluminous circumpolar waters. The latter ultimately feed back into the Atlantic, Pacific, and Indian basins as bottom and intermediate waters. The goal of this dissertation is to assess evidence for local versus remote processes in influencing the distribution of DOC in the deep ocean. We use both large-scale datasets and isotopic and molecular composition data to understand the dynamics of the DOC pool on a global scale, though with an emphasis on the southern hemisphere. Chapter 2 focuses on DOC in Antarctic shelf systems and Antarctic Bottom Water (AABW) formation; Chapter 3 looks at the mostly conservative behavior of DOC in the deep SO; Chapter 4 considers the radiocarbon content of DOC in the South Indian Ocean (SIO) to assess the age of DOC; and Chapter 5 looks at the radiocarbon and molecular composition of DOC in the far North Pacific. In Chapter 6, findings are summarized. One potential local source of DOC to the deep SO is export from Antarctic shelf systems. Antarctica's continental shelves generate the densest waters in the world ocean and are responsible for the formation of AABW. AABW has the potential to sequester carbon in the deep ocean for millennia. DOC enrichment in dense shelf waters (DSW) in the Ross Sea was quantified and the potential for DOC to be sequestered into AABW was assessed. Ross Sea DSW was enriched in DOC by ~7 [mu]mol kg-1 relative to the incoming source waters (initial conditions), primarily due to deep vertical mixing of DOC-enriched surface waters. The total DOC excess in DSW suggests that 4.0±0.6 Tg DOC y-1 is exported off the shelf. However, this exported fraction does not appear to persist in newly formed AABW and is likely remineralized, sequestering this carbon as TCO2 in the deep ocean. A test of the conservative behavior of DOC in the Southern Ocean was assessed by considering its transport within deep water masses (North Atlantic Deep Water (NADW), Indian Deep Water (IDW), and Pacific Deep Water (PDW)). Multiple approaches (multiple linear regression, mass transport, and mass balance calculations) were used with data from CLIVAR Repeat Hydrography sections to evaluate the system. DOC concentrations in the deep SO and CDW largely reflect the linear mixing of those several deep waters entering the system from the north. Mass balance suggests too that the relatively depleted DOC radiocarbon content in the deep SO is a conserved property, but limited radiocarbon profiles in the SIO prevent a full analysis of the conserved behavior of 14C age of DOC. Consequently, to further test for the conservative behavior of the 14C age of DOC in the SO, the 14C age of DOC in the SIO was assessed; these data complete a survey of ages in the major deep water masses entrained into the SO. Four profiles of the 14C content of DOC spanning the SIO were collected, ranging from the Polar Front (56oS) to the subtropics (29oS). Surface waters had bulk radiocarbon ages of ~4400 years at the Polar Front and ~2000 14C years in the subtropics. At depth, mean radiocarbon age of DOC in CDW was 5302±160 14C years, while that in IDW was significantly older at 5557±81 14C years. A high-salinity remnant of NADW intruding into the deep SIO had a distinctly younger radiocarbon age for DOC (~5100 14C years). Multiple linear regression of 14C ages was used to assess the transport of DOC in the SIO. These results additionally confirm the conservative behavior of DOC in the deep Southern Ocean. To assess how the conserved behavior of DOC can be related to the molecular composition of dissolved organic matter (DOM), the 14C age of DOC was coupled with DOM composition in PDW in the far deep North Pacific (FNP), where the ocean's oldest water masses are located. DOM in this region has an old radiocarbon age (~6400 years old) and an overall molecular composition comprised of intrinsically stable compounds with low reactivities. By correlating radiocarbon age with each molecular formulae in solid-phase extracted DOM, the majority of DOM in PDW was found to have low reactivity and slow removal rates, especially in comparison with the DOM composition from the deep North Atlantic. Overall, this dissertation uses large-scale biogeochemical distributions as well as isotopic and molecular composition techniques to show that DOC cycling in the deep SO and SIO are due to mixing. As Antarctic shelf systems do not export DOC to the deep SO, instead DOC distributions and 14C age of DOC in the SO are largely controlled by mixing of NADW, IDW, and PDW. In addition, the SIO exhibits 14C ages of DOC consistent with water mass transports into that basin. Finally, the degraded molecular characteristic and old age of PDW in the FNP suggests that DOM in that region is low in reactivity and has not been renewed for long timescales.

Analysis of Carbon Isotopes, Determination of Ground-water Age, and Estimated Characteristics of the Contaminant Source at Two Fuel-spill Plumes, Western Cape Cod, Massachusetts, 1996

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ISBN 13 :
Total Pages : 32 pages
Book Rating : 4.3/5 (121 download)

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Book Synopsis Analysis of Carbon Isotopes, Determination of Ground-water Age, and Estimated Characteristics of the Contaminant Source at Two Fuel-spill Plumes, Western Cape Cod, Massachusetts, 1996 by : Jennifer Savoie

Download or read book Analysis of Carbon Isotopes, Determination of Ground-water Age, and Estimated Characteristics of the Contaminant Source at Two Fuel-spill Plumes, Western Cape Cod, Massachusetts, 1996 written by Jennifer Savoie and published by . This book was released on 1999 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Determining the stable isotope ratio of total dissolved inorganic carbon in lake water by GC/C/IRMS

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ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (77 download)

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Book Synopsis Determining the stable isotope ratio of total dissolved inorganic carbon in lake water by GC/C/IRMS by : T. MIYAJIMA

Download or read book Determining the stable isotope ratio of total dissolved inorganic carbon in lake water by GC/C/IRMS written by T. MIYAJIMA and published by . This book was released on 1995 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Carbon Isotope Stratigraphy

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Publisher : Academic Press
ISBN 13 : 0128209925
Total Pages : 782 pages
Book Rating : 4.1/5 (282 download)

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Book Synopsis Carbon Isotope Stratigraphy by : Michael Montenari

Download or read book Carbon Isotope Stratigraphy written by Michael Montenari and published by Academic Press. This book was released on 2020-10-30 with total page 782 pages. Available in PDF, EPUB and Kindle. Book excerpt: Carbon Isotope Stratigraphy, Volume Five in the Advances in Sequence Stratigraphy series, covers research in stratigraphic disciplines, including the most recent developments in the geosciences. This fully commissioned review publication aims to foster and convey progress in stratigraphy with its inclusion of a variety of topics, including Carbon isotope stratigraphy - principles and applications, Interpreting Phanerozoic d13C patterns as periodic glacio-eustatic sequences, Stable carbon isotopes in archaeological plant remains, Review of the Upper Ediacaran-Lower Cambrian Detrital Series in Central and North Iberia: NE Africa as possible Source Area, Calibrating d13C and d18O chemostratigraphic correlations across Cambrian strata of SW, and much more. - Contains contributions from leading authorities in the field - Informs and updates on all the latest developments in the field - Aims to foster and convey progress in stratigraphy, including geochronology, magnetostratigraphy, lithostratigraphy, event-stratigraphy, and more

Time-series of Stable Isotopes in Dissolved Inorganic Carbon of Surface Seawater Near Bermuda and Hawaii

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ISBN 13 :
Total Pages : 156 pages
Book Rating : 4.:/5 (114 download)

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Book Synopsis Time-series of Stable Isotopes in Dissolved Inorganic Carbon of Surface Seawater Near Bermuda and Hawaii by : Mariela Ke'o-lani Brooks

Download or read book Time-series of Stable Isotopes in Dissolved Inorganic Carbon of Surface Seawater Near Bermuda and Hawaii written by Mariela Ke'o-lani Brooks and published by . This book was released on 2020 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: The 13C/12C ratio of stable carbon isotopes in dissolved inorganic carbon (DIC) can provide insight into carbon cycle variability and trends in the surface ocean. Measurements of [delta]13C-DIC when combined with DIC can be used to estimate anthropogenic carbon uptake and marine productivity and can contribute to our understanding of the role that the ocean plays in the global carbon cycle. This dissertation describes surface ocean time-series measurements near Bermuda (S-BATS) and Hawaii (HOT) of [delta]13C-DIC, DIC, and alkalinity (ALK) as a part of the Scripps Seawater Program, focusing on [delta]13C-DIC. Prior to this study, there was a hiatus in seawater [delta]13C-DIC measurements at Scripps, while samples continued to be collected and archived for future analysis. This dissertation details the resumption of these measurements along with the calibration and methodology used for Scripps measurements of [delta]13C-DIC. We quantify the calibration contributions to uncertainty in the context of consistency between newer and older measurements. In addition, we introduce and document the stability of three new seawater secondary standards, including a method based on CO2 in compressed N2 gas. In these time-series records of nearly three decades, we show that the long-term trends and seasonal cycles in sDIC and [delta]13C-DIC at both S-BATS and HOT are consistent with earlier studies and independent time-series records. From the full record we find no long-term changes in the seasonal cycle of sDIC, [delta]13C-DIC, or computed pCO2. Consistent to some earlier studies we find significant correlations at S-BATS with the North Atlantic Oscillation and at HOT with the Pacific Decadal Oscillation (PDO). We also find correlations at HOT that were not previously noted including the PDO with sea surface temperature and mixed layer depth (MLD), as well as El Nino Southern Oscillation (NINO3.4) with sDIC and MLD. Lastly, we use a combination of observations and CESM hindcast simulations to explore upper ocean carbon variability in subtropical gyres. This allows us to examine the time-series in a broader geographic context, showing coherent patterns of variability across the North Atlantic and North Pacific subtropical gyres and illustrating key differences in the controls of variability at BATS and HOT.

Oxygen and Carbon in the Oceans and Atmosphere: Stable Isotopes as Tracers for Consumption, Production, and Circulation Models

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ISBN 13 :
Total Pages : 568 pages
Book Rating : 4.:/5 (318 download)

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Book Synopsis Oxygen and Carbon in the Oceans and Atmosphere: Stable Isotopes as Tracers for Consumption, Production, and Circulation Models by : Peter Michael Kroopnick

Download or read book Oxygen and Carbon in the Oceans and Atmosphere: Stable Isotopes as Tracers for Consumption, Production, and Circulation Models written by Peter Michael Kroopnick and published by . This book was released on 1971 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Encyclopedia of Geochemistry

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Publisher : Springer
ISBN 13 : 9783319393117
Total Pages : 1680 pages
Book Rating : 4.3/5 (931 download)

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Book Synopsis Encyclopedia of Geochemistry by : William M. White

Download or read book Encyclopedia of Geochemistry written by William M. White and published by Springer. This book was released on 2018-07-24 with total page 1680 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Encyclopedia is a complete and authoritative reference work for this rapidly evolving field. Over 200 international scientists, each experts in their specialties, have written over 330 separate topics on different aspects of geochemistry including geochemical thermodynamics and kinetics, isotope and organic geochemistry, meteorites and cosmochemistry, the carbon cycle and climate, trace elements, geochemistry of high and low temperature processes, and ore deposition, to name just a few. The geochemical behavior of the elements is described as is the state of the art in analytical geochemistry. Each topic incorporates cross-referencing to related articles, and also has its own reference list to lead the reader to the essential articles within the published literature. The entries are arranged alphabetically, for easy access, and the subject and citation indices are comprehensive and extensive. Geochemistry applies chemical techniques and approaches to understanding the Earth and how it works. It touches upon almost every aspect of earth science, ranging from applied topics such as the search for energy and mineral resources, environmental pollution, and climate change to more basic questions such as the Earth’s origin and composition, the origin and evolution of life, rock weathering and metamorphism, and the pattern of ocean and mantle circulation. Geochemistry allows us to assign absolute ages to events in Earth’s history, to trace the flow of ocean water both now and in the past, trace sediments into subduction zones and arc volcanoes, and trace petroleum to its source rock and ultimately the environment in which it formed. The earliest of evidence of life is chemical and isotopic traces, not fossils, preserved in rocks. Geochemistry has allowed us to unravel the history of the ice ages and thereby deduce their cause. Geochemistry allows us to determine the swings in Earth’s surface temperatures during the ice ages, determine the temperatures and pressures at which rocks have been metamorphosed, and the rates at which ancient magma chambers cooled and crystallized. The field has grown rapidly more sophisticated, in both analytical techniques that can determine elemental concentrations or isotope ratios with exquisite precision and in computational modeling on scales ranging from atomic to planetary.

Water Resources Data for Ohio

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ISBN 13 :
Total Pages : 862 pages
Book Rating : 4.3/5 (243 download)

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Book Synopsis Water Resources Data for Ohio by :

Download or read book Water Resources Data for Ohio written by and published by . This book was released on 1976 with total page 862 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Automated Procedures for Determining Dissolved Organic Carbon and Halogenated Organic Compound Concentrations in Surface Waters

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ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (871 download)

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Book Synopsis Automated Procedures for Determining Dissolved Organic Carbon and Halogenated Organic Compound Concentrations in Surface Waters by :

Download or read book Automated Procedures for Determining Dissolved Organic Carbon and Halogenated Organic Compound Concentrations in Surface Waters written by and published by . This book was released on 1979 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Biogeochemical Dynamics at Major River-Coastal Interfaces

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Publisher : Cambridge University Press
ISBN 13 : 1107022576
Total Pages : 673 pages
Book Rating : 4.1/5 (7 download)

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Book Synopsis Biogeochemical Dynamics at Major River-Coastal Interfaces by : Thomas Bianchi

Download or read book Biogeochemical Dynamics at Major River-Coastal Interfaces written by Thomas Bianchi and published by Cambridge University Press. This book was released on 2014 with total page 673 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive, state-of-the-art synthesis of biogeochemical dynamics and the impact of human alterations at major river-coastal interfaces for advanced students and researchers.

A Study of Remineralization of Organic Carbon in Nearshore Sediments Using Carbon Isotopes

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ISBN 13 :
Total Pages : 225 pages
Book Rating : 4.:/5 (143 download)

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Book Synopsis A Study of Remineralization of Organic Carbon in Nearshore Sediments Using Carbon Isotopes by : Ann P. McNichol

Download or read book A Study of Remineralization of Organic Carbon in Nearshore Sediments Using Carbon Isotopes written by Ann P. McNichol and published by . This book was released on 1986 with total page 225 pages. Available in PDF, EPUB and Kindle. Book excerpt: A study of the remineralization of organic carbon was conducted in the organic-rich sediments of Buzzards Bay, MA. Major processes affecting the carbon chemistry in sediments are reflected by changes in the stable carbon isotope ratios of dissolved inorganic carbon (XCO2) in sediment pore water. Six cores were collected seasonally over a period of two years. The following species were measured in the pore waters: JC02, & '3 C-2CO2, P04, JH 2S, Alk, DOC, and Ca. Measurements of pore water collected seasonally show large gradients with depth, which are larger in summer than in winter. The 613C (PDB) of IC02 varies from 1.3 o/oo in the bottom water to approximately -10 o/oo at 30 cm. During all seasons, there was a trend towards more negative values with depth in the upper 8 cm due to the remineralization of organic matter. There was a trend toward more positive values below 8 cm, most likely due to biological irrigation of sediments with bottom water. Below 16-20 cm, a negative gradient was re-established which indicates a return to remineralization as the main process affecting pore water chemistry. Using the XC02 depth profile, it was estimated that 67-85 gC/m 2 are oxidized annually and 5 gC/m 2-yr are buried. The amount of carbon oxidized represented remineralization occurring within the sediments. This estimate indicated that approximately 20% of the annual primary productivity reached the sediments. The calculated remineralization rates varied seasonally with the high of 7.5 x 10-' mol/L-sec observed in August 84 and the low (0.6 x 10- ) in December 83. The calculated remineralization rates were dependent on the amount of irrigation in the sediments; if the irrigation parameter is known to ±20%, then the remineralization rates are known to this certainty also. The amount of irrigation in the sediments was estimated using the results of a seasonal study of 2 2 2Rn/ 22 'Ra disequilibria at the same study site (Martin, 1985). Estimates of the annual remineralization in the sediments using solid-phase data indicated that the solid-phase profiles were not at steady-state concentrations. The isotopic signature of 2C02 was used as an indicator of the processes affecting IC02 in pore water. During every month, the oxidation of organic carbon to C02 provided over half of the carbon added to the IC02 pool. However, in every month, the 6'"C of XCO2 added to the pore water in the surface sediments was greater than -15 o/oo, significantly greater than the 613C of solid-phase organic carbon in the sediments ( -20.6 o/oo). The 613C of IC02 added to the pore water in the sediments deeper than 7 cm was between -20 and -21 o/oo, similar to the organic carbon in the sediments. Possible explanations of the 1 3C-enrichment observed in the surface sediments were: a) significant dissolution of CaC0 3 (613C = +1.7 o/oo) b) the addition of significant amounts of carbonate ion from bottom water to pore water c) an isotopic difference between the carbon oxidized in the sediments and that remaining in the sediments. The effect of CaC0 3 dissolution was quantified using measured dissolved Ca profiles and was not large enough to explain the observed isotopic enrichment. An additional source of 13C-enriched carbon was bottom water carbonate ion. In every month studied, there was a net flux of 2C0 2 from pore water to bottom water. The flux of pore water 2C02 to bottom water ranged from a minimum of 10 x 10-12 mol/cm 2 -sec in December 83 to a maximum of 50 x 10-12 mol/cm2-sec in August 84. However, because the pH of bottom water was about 8 while that of the pore water was less than or equal to 7, the relative proportion of the different species of inorganic carbon (H2CO, HCO-, C0~) was very different in bottom water and pore water. Thus, while there was a net flux of IC0 2 from pore water to bottom water, there was a flux of carbonate ion from bottom water to pore water. Because bottom water JC02 was more 13C-enriched than pore water JC0 2, the transfer of bottom water carbonate ion to pore water was a source of 13C-enriched carbon to the pore water. If the & '3C of CO2 added to the pore water from the oxidation of organic carbon was -20.6 o/oo, then the flux of C3% from bottom water to pore water must have been 10-30% of the total flux of 2C02 from pore water to bottom water. This is consistent with the amount calculated from the observed gradient in carbonate ion. Laboratory experiments were conducted to determine whether the 613C of C02 produced from the oxidation of organic carbon (613C-OCOX) was different from the 613C of organic carbon in the sediments (613C-SOC). In the laboratory experiments, mud from the sampling site was incubated at a constant temperature. Three depths were studied (0-3, 10-15, and 20-25 cm). For the first study (IEl), sediment was stirred to homogenize it before packing into centrifuge tubes for incubation. For the second study (IE2), sediment was introduced directly into glass incubation tubes by subcoring. The second procedure greatly reduced disturbance to the sediment. Rates of C02 production were calculated from the concentrations of 2C02 measured over up to 46 days. In both studies, the values of Re in the deeper intervals were about 10% of the surface values. This was consistent with the field results, although the rates decreased more rapidly in the field. In all cases, the remineralization rates during the beginning of IEl were much greater than those at the beginning of IE2. The sediment for IEl was collected in February 84. The measured value of Rc in the surface sediment of the laboratory experiment (24 x 10- mol/L-sec) was much greater than the value of Rc observed in the field in another winter month, December 83 (.62 x 10~9). The sediment for IE2 was collected in August 85. The measured values of Re in the surface sediment (6.6-12 x 10~9 mol/L-sec) were consistent with the field values from August 84 (7.5 x 10-9). The XC02 results indicated that IE2 reproduced field conditions more accurately than IEl did. The isotopic results from the experiments strongly suggested that 613C-OCOX in the surface sediments ( -17.8 o/oo ± 1.9 o/oo) was greater than 6'3C-SOC ( -20.6 ± 0.2 o/oo). The magnitude of the observed fractionation was small enough that the observed values of 613C-C02 in the pore waters could be explained by fractionated oxidation coupled with the diffusion of carbonate ion from bottom water to pore water. The observed fractionation was most likely due to the multiple sources of organic carbon to coastal sediments. A study of the natural levels of radiocarbon in these sediments indicated that the carbon preserved in the sediments is approximately 30% terrestrial while the rest is from phytoplankton.

Use of Proxies in Paleoceanography

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Publisher : Springer Science & Business Media
ISBN 13 : 3642586465
Total Pages : 768 pages
Book Rating : 4.6/5 (425 download)

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Book Synopsis Use of Proxies in Paleoceanography by : Gerhard Fischer

Download or read book Use of Proxies in Paleoceanography written by Gerhard Fischer and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 768 pages. Available in PDF, EPUB and Kindle. Book excerpt: Paleoceanographic proxies provide infonnation for reconstructions of the past, including climate changes, global and regional oceanography, and the cycles of biochemical components in the ocean. These prox ies are measurable descriptors for desired but unobservable environmental variables such as tempera ture, salinity, primary productivity, nutrient content, or surface-water carbon dioxide concentrations. The proxies are employed in a manner analogous to oceanographic methods. The water masses are first characterized according to their specific physical and chemical properties, and then related to particular assemblages of certain organisms or to particular element or isotope distributions. We have a long-standing series of proven proxies available. Marine microfossil assemblages, for instance, are employed to reconstruct surface-water temperatures. The calcareous shells of planktonic and benthic microorgan isms contain a wealth of paleoceanographic information in their isotopic and elemental compositions. Stable oxygen isotope measurements are used to detennine ice volume, and MglCa ratios are related to water temperatures, to cite a few examples. Organic material may also provide valuable infonnation, e. g. , about past productivity conditions. Studying the stable carbon isotope composition of bulk organic matter or individual marine organic components may provide a measure of past surface-water CO 2 conditions within the bounds of certain assumptions. Within the scope of paleoceanographic investigations, the existing proxies are continuously evolving and improving, while new proxies are being studied and developed. The methodology is improved by analysis of samples from the water column and surface sediments, and through laboratory experiments.

The Origins and Relationships of Lower Invertebrates

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Publisher : Oxford University Press, USA
ISBN 13 :
Total Pages : 424 pages
Book Rating : 4.:/5 (43 download)

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Book Synopsis The Origins and Relationships of Lower Invertebrates by : Simon Conway Morris

Download or read book The Origins and Relationships of Lower Invertebrates written by Simon Conway Morris and published by Oxford University Press, USA. This book was released on 1985 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presenting a broad overview of current trends and recent research, this book discusses such groups as sponges, ctenophores, rotifers, annelids, and pogonophores. The book's assessment of lower invertebrates include investigations of reproduction and larval development relevant to phylogeny, problems of pseudocoelomate evolution, and the fossil record of lower invertebrates.

Inorganic Carbon Isotopes and Chemical Characterization of Watershed Drainages, Barrow, Alaska, 2013

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ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (925 download)

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Book Synopsis Inorganic Carbon Isotopes and Chemical Characterization of Watershed Drainages, Barrow, Alaska, 2013 by :

Download or read book Inorganic Carbon Isotopes and Chemical Characterization of Watershed Drainages, Barrow, Alaska, 2013 written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Arctic soils contain a large pool of terrestrial C and are of interest due to their potential for releasing significant carbon dioxide (CO2) and methane (CH4) to the atmosphere. Due to substantial landscape heterogeneity, predicting ecosystem-scale CH4 and CO2 production is challenging. This study assessed dissolved inorganic carbon (DIC = Sigma (total) dissolved CO2) and CH4 in watershed drainages in Barrow, Alaska as critical convergent zones of regional geochemistry, substrates, and nutrients. In July and September of 2013, surface waters and saturated subsurface pore waters were collected from 17 drainages. Based on simultaneous DIC and CH4 cycling, we synthesized isotopic and geochemical methods to develop a subsurface CH4 and DIC balance by estimating mechanisms of CH4 and DIC production and transport pathways and oxidation of subsurface CH4. We observed a shift from acetoclastic (July) towards hydrogenotropic (September) methanogenesis at sites located towards the end of major freshwater drainages, adjacent to salty estuarine waters, suggesting an interesting landscape-scale effect on CH4 production mechanism. The majority of subsurface CH4 was transported upward by plant-mediated transport and ebullition, predominantly bypassing the potential for CH4 oxidation. Thus, surprisingly CH4 oxidation only consumed approximately 2.51 +/- 0.82% (July) and 0.79 +/- 0.79% (September) of CH4 produced at the frost table, contributing to less than 0.1% of DIC production. DIC was primarily produced from respiration, with iron and organic matter serving as likely e- acceptors. This work highlights the importance of spatial and temporal variability of CH4 production at the watershed scale, and suggests broad scale investigations are required to build better regional or pan-Arctic representations of CH4 and CO2 production.

Stable Carbon Isotopes in Deep Sea Pore Waters

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ISBN 13 :
Total Pages : 240 pages
Book Rating : 4.:/5 (318 download)

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Book Synopsis Stable Carbon Isotopes in Deep Sea Pore Waters by : Daniel Charles McCorkle

Download or read book Stable Carbon Isotopes in Deep Sea Pore Waters written by Daniel Charles McCorkle and published by . This book was released on 1987 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: