Download or read book Application of Transport reaction Modeling to Constrain Biogeochemical Processes in Marine Sediments written by Wei-Li Hong and published by . This book was released on 2014 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt: Quantifying the mass transport through marine sediments, and the geochemical response to such flow with numerical models has become a common and powerful approach for geochemical data interpretation. In this dissertation, I developed and applied transport-reaction models to unravel complex and interdependent reactions involving carbon, sulfur and silica transformations in shallow marine sediments, and the impact of physical (mass transport deposits) and depositional events (volcanic ash input) on the overall geochemical state of the system. Carbon cycling in the gas hydrate bearing sediments of the Ulleung Basin was quantified using both box and kinetic modeling approaches. The box model balances mass, flux, and carbon isotopes of carbon (Chapter 2), and led to a better understanding of how methane is cycled in the marine sediments of this area. This effort demonstrates the significance of CO2 reduction, a previously overlooked reaction. The picture of reaction network derived from this work serves as the foundation for a transport-reaction model (Chapter 3). The kinetic model results revealed a very different biogeochemistry between two distinct fluid-flow environments. At sites where transport is predominantly diffusive (non-chimney environments), organic matter decomposition is the dominant process driving production of methane, dissolved inorganic carbon (DIC) and consumption of sulfate. In contrast, anaerobic oxidation of methane (AOM) drives both carbon and sulfur cycles in the advective settings characterized by acoustic chimneys indicative of gas transport. I show that methane produced within the model domain, through CO2 reduction and methanogenesis, fuels AOM in the non-chimney sites while AOM is primarily induced by methane from external sources at the chimney sites. A simulation of the system evolution from a non-chimney to a chimney condition was developed by increasing the bottom methane supply to an originally diffusion-controlled site. Results from this exercise show that the higher methane flux leads to a higher AOM activity, and enhanced organic matter decomposition through methanogenesis. Organic carbon cycling is also affected by changes in the depositional environment, as shown by application of the kinetic model to the sediments from the Krishna-Godavary (K-G) basin along the eastern Indian margin (Chapter 4). Proximity to large rivers results in the widespread occurrence of mass transport deposits (MTD) throughout the basin. In this work, MTD is defined as a fluidized sediment block whose pore water composition is identical to sea water value to reflect the homogenization process during sediment transport. The pore water sulfate and ammonium profiles measured at seven sites drilled in the K-G Basin during the NGHP-01 expedition were simulated to provide a quantitative description of how MTDs can affect geochemistry profiles, not only for sulfate and ammonium but potentially all pore water species. This model provides reliable estimates of the MTDs thickness, the time elapsed after the most recent event, and the organoclastic sulfate reduction rate at these seven sites. A transport-reaction modeling approach was also applied to investigate the silica diagenetic reactions fueled by volcanic ash decomposition in Shikuko Basin, Nankai Trough (Chapter 5). The model developed for this setting reproduces a silica diagenetic boundary (SDB) at each site, which is defined by marked decreases in reactive volcanic ash, pore water silica and potassium. Volcanic ash alteration was constrained by modeling pore water 87Sr/86Sr profiles. Below the SDB, formation of clinoptilolite consumes potassium and regulates the extension of amorphous silica by consuming SiO2(aq). The observed low SiO2(aq) and dissolved potassium in these deep sequences require continuous precipitation of clinoptilolite; however in order to maintain oversaturation of this mineral at the low SiO2(aq) in sediments below the SDB, an increase in pH is required, consistent with pore water observations. Thermal history, rather than temperature alone, controls the inferred reaction network as shown by the convergence of the thermal maturity of sediments at the SDB from all studied sites and is consistent with other locations documented onshore Japan. These results are valuable as we move forward in understanding the mechanisms and consequences of ash alteration in convergent margins worldwide.

Download or read book Reactive Transport in Natural Porous Media written by Babak Shafei and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Reactive Transport Models (RTMs) provide quantitative tools to analyze the interaction between transport and biogeochemical processes in subsurface environments such as aquatic sediments and groundwater flow. A tremendous amount of research has shown the role and impact of scaling behavior of the reactive systems which stems from geologic heterogeneity. Depending on the kinetics of the reactions, different types of formulations have been proposed to describe reactions in RTMs. We introduce a novel quantitative criteria on the range of validity of local equilibrium assumption (LEA) in aquatic sediments with irreversible heterogeneous sorption reactions. Then we present a one-dimensional (1-D) early diagenetic module, MATSEDLAB, developed in MATLAB. The module provides templates for representing the reaction network, boundary conditions and transport regime, which the user can modify to fit the particular early diagenetic model configuration of interest. We describe the theoretical background of the model and introduce the MATLAB pdepe solver, followed by calibration and validation of the model by a number of theoretical and empirical applications. Finally, we introduce a new pore-scale model using lattice Boltzmann (LB) approach. It uses an iterative scheme for the chemical transport-reaction part and recent advances in the development of optimal advection-diffusion solvers within the lattice Boltzmann method framework. We present results for the dissolution and precipitation of a porous medium under different dynamical conditions, varying reaction rates and the ratio of advective to diffusive transport (Pe, Peclet number) for linear reactions. The final set of calculations considers sorption reactions on a heterogeneous porous medium. We use our model to investigate the effect of heterogeneity on the pore-scale distribution of sorption sites and the competition between three different sorption reactions.

Download or read book Towards a Model of Ocean Biogeochemical Processes written by Geoffrey T. Evans and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 351 pages. Available in PDF, EPUB and Kindle. Book excerpt: Key biogeochemical events in the ocean take place in less than a second, are studied in experiments lasting a few hours, and determine cycles that last over seasons or even years. Models of the controlling processes thus have to take into account these time scales. This book aims at achieving consensus among these controlling processes at all relevant time scales. It helps understand the global carbon cycle including the production and breakdown of solved organic matter and the production, sinking and breakdown of particles. The emphasis on considering all time scales in submodel formulation is new and of interest to all those working in global ocean models and related fields.

Download or read book Treatise on Geochemistry written by and published by Newnes. This book was released on 2013-10-19 with total page 14787 pages. Available in PDF, EPUB and Kindle. Book excerpt: This extensively updated new edition of the widely acclaimed Treatise on Geochemistry has increased its coverage beyond the wide range of geochemical subject areas in the first edition, with five new volumes which include: the history of the atmosphere, geochemistry of mineral deposits, archaeology and anthropology, organic geochemistry and analytical geochemistry. In addition, the original Volume 1 on "Meteorites, Comets, and Planets" was expanded into two separate volumes dealing with meteorites and planets, respectively. These additions increased the number of volumes in the Treatise from 9 to 15 with the index/appendices volume remaining as the last volume (Volume 16). Each of the original volumes was scrutinized by the appropriate volume editors, with respect to necessary revisions as well as additions and deletions. As a result, 27% were republished without major changes, 66% were revised and 126 new chapters were added. In a many-faceted field such as Geochemistry, explaining and understanding how one sub-field relates to another is key. Instructors will find the complete overviews with extensive cross-referencing useful additions to their course packs and students will benefit from the contextual organization of the subject matter Six new volumes added and 66% updated from 1st edition. The Editors of this work have taken every measure to include the many suggestions received from readers and ensure comprehensiveness of coverage and added value in this 2nd edition The esteemed Board of Volume Editors and Editors-in-Chief worked cohesively to ensure a uniform and consistent approach to the content, which is an amazing accomplishment for a 15-volume work (16 volumes including index volume)!

Download or read book Diagenetic Models and Their Implementation written by Bernard P. Boudreau and published by Springer. This book was released on 2011-10-05 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The study of sedimentary chemistry and its associated processes is becoming far more mathematical. This new emphasis is being driven by pressures originating from both basic research and field applications. There is a growing desire to gain a quantitative understanding of the reasons for the natural chemical changes observed in sediments as they are buried. Past textbooks have not emphasized the steps necessary to develop transport-reaction (diagenetic) models themselves nor methods for their solution. This book attempts to correct this situation by presenting a detailed account of model formulation by explaining some useful solution techniques. The choice of material illustrates methods that are simple to explain and implement, yet powerful enough to attack even the most complicated diagenetic problems. Computer programs that implement and illustrate the numerical methods are also made available.

Download or read book On Redox Reactions and Transport Processes of Solutes in Coastal Marine Sediments written by Ida-Maja Karle and published by Analystical and Marine Chemistry Department of Chemisty Goteborg. This book was released on 2006-01-01 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Reactive Transport in Porous Media written by Peter C. Lichtner and published by Walter de Gruyter GmbH & Co KG. This book was released on 2018-12-17 with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt: Volume 34 of Reviews in Mineralogy focuses on methods to describe the extent and consequences of reactive flow and transport in natural subsurface systems. Since the field of reactive transport within the Earth Sciences is a highly multidisciplinary area of research, including geochemistry, geology, physics, chemistry, hydrology, and engineering, this book is an attempt to some extent bridge the gap between these different disciplines. This volume contains the contributions presented at a short course held in Golden, Colorado, October 25-27, 1996 in conjunction with the Mineralogical Society of America's (MSA) Annual Meeting with the Geological Society of America in Denver, Colorado.

Download or read book An Inverse Model for Reactive Transport in Biogeochemical Systems written by Christof D. Meile and published by . This book was released on 1999 with total page 430 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Biogeochemistry and Genomics of Silicification and Silicifiers volume II written by Brivaela Moriceau and published by Frontiers Media SA. This book was released on 2024-09-02 with total page 181 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the second issue of the Research Topic: Biogeochemistry and Genomics of Silicification and Silicifiers. The first issue article collection can be found here: https://www.frontiersin.org/research-topics/5364/biogeochemistry-and-genomics-of-silicification-and-silicifiers Silicifiers are among the most important living organisms of planet Earth. They are able to take advantage of the abundance of silicon in the Earth crust to build silicified architectures, which in particular can help for protection against predators or for facilitating the penetration of light and nutrients to the cells.

Download or read book Linking Hydrological and Biogeochemical Processes in Riparian Corridors written by Dipankar Dwivedi and published by Frontiers Media SA. This book was released on 2021-07-22 with total page 285 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Geochemical and Biogeochemical Reaction Modeling written by Craig M. Bethke and published by Cambridge University Press. This book was released on 2010-12-09 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a comprehensive overview of reaction processes in the Earth's crust and on its surface, both in the laboratory and in the field. A clear exposition of the underlying equations and calculation techniques is balanced by a large number of fully worked examples. The book uses The Geochemist's Workbench® modeling software, developed by the author and already installed at over 1000 universities and research facilities worldwide. Since publication of the first edition, the field of reaction modeling has continued to grow and find increasingly broad application. In particular, the description of microbial activity, surface chemistry, and redox chemistry within reaction models has become broader and more rigorous. These areas are covered in detail in this new edition, which was originally published in 2007. This text is written for graduate students and academic researchers in the fields of geochemistry, environmental engineering, contaminant hydrology, geomicrobiology, and numerical modeling.

Download or read book Thermodynamics and Kinetics of Water Rock Interaction written by Eric H. Oelkers and published by Walter de Gruyter GmbH & Co KG. This book was released on 2018-12-17 with total page 588 pages. Available in PDF, EPUB and Kindle. Book excerpt: Volume 70 of Reviews in Mineralogy and Geochemistry represents an extensive review of the material presented by the invited speakers at a short course on Thermodynamics and Kinetics of Water-Rock Interaction held prior to the 19th annual V. M. Goldschmidt Conference in Davos, Switzerland (June 19-21, 2009). Contents: Thermodynamic Databases for Water-Rock Interaction Thermodynamics of Solid Solution-Aqueous Solution Systems Mineral Replacement Reactions Thermodynamic Concepts in Modeling Sorption at the Mineral-Water Interface Surface Complexation Modeling: Mineral Fluid Equilbria at the Molecular Scale The Link Between Mineral Dissolution/Precipitation Kinetics and Solution Chemistry Organics in Water-Rock Interactions Mineral Precipitation Kinetics Towards an Integrated Model of Weathering, Climate, and Biospheric Processes Approaches to Modeling Weathered Regolith Fluid-Rock Interaction: A Reactive Transport Approach Geochemical Modeling of Reaction Paths and Geochemical Reaction Networks

Download or read book Early Diagenesis written by Robert A. Berner and published by Princeton University Press. This book was released on 1980-08-21 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses mainly on the chemical composition of interstitial waters of sediments. Chapter 2 presents the basic theory used throughout the rest of the book in terms of a general diagenetic equation. Chapters 3,4,and 5 provides detailed discussion of each of the terms in general diagenetic equation as well as presentations of data. Chapters 6,7 and 8 gives examples of diagenetic calculation using the theory developed earlier.

Download or read book Oceanobs 19 An Ocean of Opportunity Volume II written by Tong Lee and published by Frontiers Media SA. This book was released on 2020-12-31 with total page 629 pages. Available in PDF, EPUB and Kindle. Book excerpt: This eBook is a collection of articles from a Frontiers Research Topic. Frontiers Research Topics are very popular trademarks of the Frontiers Journals Series: they are collections of at least ten articles, all centered on a particular subject. With their unique mix of varied contributions from Original Research to Review Articles, Frontiers Research Topics unify the most influential researchers, the latest key findings and historical advances in a hot research area! Find out more on how to host your own Frontiers Research Topic or contribute to one as an author by contacting the Frontiers Editorial Office: frontiersin.org/about/contact.

Download or read book Biogeochemical Processes in Marine Sediments with Emphasis on the Nitrogen Cycle and Oxygen Dynamics written by Johannes Frederik Bakker and published by . This book was released on 1992 with total page 99 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Marine Carbon Biogeochemistry written by Jack J. Middelburg and published by Springer. This book was released on 2019-01-25 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt: This open access book discusses biogeochemical processes relevant to carbon and aims to provide readers, graduate students and researchers, with insight into the functioning of marine ecosystems. A carbon centric approach has been adopted, but other elements are included where relevant or needed. The book focuses on concepts and quantitative understanding of primary production, organic matter mineralization and sediment biogeochemistry. The impact of biogeochemical processes on inorganic carbon dynamics and organic matter transformation are also discussed.

Download or read book Modeling of marine biogeochemical cycles with an emphasis on vertical particle fluxes written by Regina Usbeck and published by . This book was released on 1999 with total page 105 pages. Available in PDF, EPUB and Kindle. Book excerpt: