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122 results on '"Plancherel, Yves"'

1. Ethnobotanical survey of medicinal and ritual plants utilized by the indigenous communities of Benguet province, Philippines

Author

Andalan, Janna R., Mondejar, Alissa Jane S., Sumaya, Nanette Hope N., Guihawan, Jaime Q., Madamba, Ma. Reina Suzette B., Baltazar Tabelin, Carlito, Guilingen, David, Paglinawan, Florifern C., Maulas, Kryzzyl M., Arquisal, Isidro, Beltran, Arnel B., Orbecido, Aileen H., Promentilla, Michael Angelo, Alonzo, Dennis, Pisda, Pamela Flynn, Ananayo, Alleah, Suelto, Marlon, Dalona, Irish Mae, Resabal, Vannie Joy, Armstrong, Robin, Jungblut, Anne D., Santos, Ana, Brito-Parada, Pablo, Plancherel, Yves, Herrington, Richard, and Villacorte-Tabelin, Mylah

Published
2024
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2. Bayesian material flow analysis for systems with multiple levels of disaggregation and high dimensional data

Author

Wang, Junyang, Ray, Kolyan, Brito-Parada, Pablo, Plancherel, Yves, Bide, Tom, Mankelow, Joseph, Morley, John, Stegemann, Julia, and Myers, Rupert

Subjects
Statistics - Applications
Abstract

Material Flow Analysis (MFA) is used to quantify and understand the life cycles of materials from production to end of use, which enables environmental, social and economic impacts and interventions. MFA is challenging as available data is often limited and uncertain, leading to an underdetermined system with an infinite number of possible stocks and flows values. Bayesian statistics is an effective way to address these challenges by principally incorporating domain knowledge, and quantifying uncertainty in the data and providing probabilities associated with model solutions. This paper presents a novel MFA methodology under the Bayesian framework. By relaxing the mass balance constraints, we improve the computational scalability and reliability of the posterior samples compared to existing Bayesian MFA methods. We propose a mass based, child and parent process framework to model systems with disaggregated processes and flows. We show posterior predictive checks can be used to identify inconsistencies in the data and aid noise and hyperparameter selection. The proposed approach is demonstrated on case studies, including a global aluminium cycle with significant disaggregation, under weakly informative priors and significant data gaps to investigate the feasibility of Bayesian MFA. We illustrate just a weakly informative prior can greatly improve the performance of Bayesian methods, for both estimation accuracy and uncertainty quantification.

Published
2022

3. Working with the community for the rehabilitation of legacy mines: Approaches and lessons learned from the literature

Author

Alonzo, Dennis, Tabelin, Carlito Baltazar, Dalona, Irish Mae, Abril, Jan Michael Vincent, Beltran, Arnel, Orbecido, Aileen, Villacorte-Tabelin, Mylah, Resabal, Vannie Joy, Promentilla, Michael Angelo, Suelto, Marlon, Brito-Parada, Pablo R., Plancherel, Yves, Jungblut, Anne D., Armstrong, Robin, Santos, Ana, Schofield, Paul F., and Herrington, Richard

Published
2024
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7. The large-scale evolution of neodymium isotopic composition in the global modern and Holocene ocean revealed from seawater and archive data

Author

Tachikawa, Kazuyo, Arsouze, Thomas, Bayon, Germain, Bory, Aloys, Colin, Christophe, Dutay, Jean-Claude, Frank, Norbert, Giraud, Xavier, Gourlan, Alexandra T., Jeandel, Catherine, Lacan, François, Meynadier, Laure, Montagna, Paolo, Piotrowski, Alexander M., Plancherel, Yves, Pucéat, Emmanuelle, Roy-Barman, Matthieu, and Waelbroeck, Claire

Published
2017
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9. Simulating marine neodymium isotope distributions using Nd v1.0 coupled to the ocean component of the FAMOUS–MOSES1 climate model: sensitivities to reversible scavenging efficiency and benthic source distributions

Author

Robinson, Suzanne, primary, Ivanovic, Ruza F., additional, Gregoire, Lauren J., additional, Tindall, Julia, additional, van de Flierdt, Tina, additional, Plancherel, Yves, additional, Pöppelmeier, Frerk, additional, Tachikawa, Kazuyo, additional, and Valdes, Paul J., additional

Published
2023
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11. Development of a site-specific system for the rehabilitation of a former copper mine, Sto. Niño, Philippines

Author

Herrington, Richard, primary, Alonzo, Dennis, additional, Armstrong, Robin, additional, Balbao, CJ, additional, Baniasadi, M, additional, Beltran, A, additional, Brito-Parada, PR, additional, Cording, HM, additional, Creedy, S, additional, Fernandez-Dalona, Irish Mae, additional, Dybowska, A, additional, Graham, A, additional, Guihawan, J, additional, Jungblut, AD, additional, Madamba, RS, additional, Magliulo, M, additional, Maulas, K, additional, Mondejar, AJ, additional, Orbecido, A, additional, Paglinawan, F, additional, Plancherel, Yves, additional, Prasow-Emond, M, additional, Promentilla, MA, additional, Rasheed, S, additional, Resabal, VJ, additional, Salatino, S, additional, Santos, A, additional, Schofield, PF, additional, Suelto, M, additional, Sumaya, NH, additional, Tabelin, CB, additional, and Villacorte-Tabelin, M, additional

Published
2023
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12. Working with the Community for the Rehabilitation of Legacy Mines: Approaches and Lessons Learned from the Literature

Author

Alonzo, Dennis, primary, Tabelin, Carlito Baltazar, additional, Dalona, Irish Mae, additional, Abril, Jan Michael Vincent, additional, Beltran, Arnel, additional, Orbecido, Aileen H., additional, Villacorte-Tabelin, Mylah, additional, Resabal, Vannie Joy, additional, Promentilla, Michael, additional, Suelto, Marlon Cañones, additional, Brito-Parada, Pablo R., additional, Plancherel, Yves, additional, Jungblut, Anne D., additional, Armstrong, Robin, additional, Santos, Ana, additional, Schofield, Paul, additional, and Herrington, Richard, additional

Published
2023
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13. Development of a site-specific system for the rehabilitation of legacy mines: The challenges of social, geological, hydrological, and biological data integration

Author

Armstrong, Robin, primary, Alonzo, Dennis, additional, Fernandez-Dalona, Irish Mae, additional, Villacorte-Tabelin, M, additional, Tabelin, CB, additional, Beltran, A, additional, Orbecido, A, additional, Brito-Parada, PR, additional, Plancherel, Yves, additional, Santos, A, additional, Herrington, Richard, additional, Jungblut, AD, additional, Schofield, PF, additional, Promentilla, MA, additional, Resabal, VJ, additional, Pisda, PF, additional, Ananayo, A, additional, Lawangen, A, additional, and Suelto, M, additional

Published
2023
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14. Bio+Mine Project: Empowering the Community to Develop a Site-Specific System for the Rehabilitation of a Legacy Mine

Author

Alonzo, Dennis, primary, Tabelin, Carlito Baltazar, additional, Dalona, Irish Mae, additional, Beltran, Arnel, additional, Orbecido, Aileen, additional, Villacorte-Tabelin, Mylah, additional, Resabal, Vannie Joy, additional, Promentilla, Michael Angelo, additional, Brito-Parada, Pablo, additional, Plancherel, Yves, additional, Jungblut, Anne D., additional, Armstrong, Robin, additional, Santos, Ana, additional, Schofield, Paul F., additional, and Herrington, Richard, additional

Published
2023
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15. Influence of the Southern Hemisphere supergyre on Antarctic Intermediate Water properties in CMIP6 models

Author

Meuriot, Ophélie, Plancherel, Yves, and Lique, Camille

Abstract

The Southern Hemisphere supergyre connects the Atlantic, Pacific, and Indian basins and is a key pathway in the global overturning circulation. The supergyre properties are investigated in the historical simulation of CMIP6 models and compared to the ECCO reanalysis product. The vertical structure of the supergyre is assessed by calculating strength and position metrics as a function of depth. The study aims to identify how the supergyre metrics at intermediate depths influence the properties and circulation of Antarctic Intermediate Water (AAIW).Results suggest that the connectivity of the supergyre across basins varies strongly with depth and across models. In CMIP6 models, the supergyre appears well-connected through all basins at the surface, via the Indonesian Throughflow and Tasman Leakage. At intermediate depths, CMIP6 models differ, with some CMIP6 models showing a connected supergyre in all three basins whereas other models present a disconnected Pacific basin. In all CMIP6 models, the supergyre becomes increasingly more disconnected with depth. The properties of AAIW (depth, salinity, temperature and density) are calculated at its core location, defined as the position of the vertical salinity minimum. Linkages between AAIW properties and the supergyre at intermediate depths were identified, with the deepest values of AAIW found at the centre of the supergyre. AAIW core properties present reduced variability within the supergyre compared to outside the supergyre. Results suggest that the heterogeneity of AAIW core properties within the supergyre depend on the models representation of the supergyre at intermediate depths., The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

Published
2023

16. Supplemental Material - Bio+Mine Project: Empowering the Community to Develop a Site-Specific System for the Rehabilitation of a Legacy Mine

Author

Alonzo, Dennis, Tabelin, Carlito Baltazar, Dalona, Irish Mae, Beltran, Arnel, Orbecido, Aileen, Villacorte-Tabelin, Mylah, Resabal, Vannie Joy, Promentilla, Michael Angelo, Brito-Parada, Pablo, Plancherel, Yves, Jungblut, Anne D., Armstrong, Robin, Santos, Ana, Schofield, Paul F., and Herrington, Richard

Subjects
111099 Nursing not elsewhere classified, 111708 Health and Community Services, 160807 Sociological Methodology and Research Methods, FOS: Health sciences, FOS: Sociology
Abstract

Supplemental Material for Bio+Mine Project: Empowering the Community to Develop a Site-Specific System for the Rehabilitation of a Legacy Mine by Dennis Alonzo, Carlito Baltazar Tabelin, Irish Mae Dalona, Arnel Beltran, Aileen Orbecido, Mylah Villacorte-Tabelin, Vannie Joy Resabal, Michael Angelo Promentilla, Pablo Brito-Parada, Yves Plancherel, Anne D. Jungblut, Robin Armstrong, Ana Santos, Paul F. Schofield, and Richard Herrington in International Journal of Qualitative Methods.

Published
2023
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18. Resource requirements for ecosystem conservation: A combined industrial and natural ecology approach to quantifying natural capital use in nature:Quantifying ecosystem needs

Author

Mason, Adam R., Gathorne-Hardy, Alfy, White, Chris, Plancherel, Yves, Woods, Jem, and Myers, Rupert J.

Subjects
conservation, resource management, Natural resources, biodiversity
Abstract

Socioeconomic demand for natural capital is causing catastrophic losses of biodiversity and ecosystem functionality, most notably in regions where socioeconomic-and eco-systems compete for natural capital, e.g., energy (animal or plant matter). However, a poor quantitative understanding of what natural capital is needed to support biodiversity in ecosystems, while at the same time satisfy human development needs-those associated with human development within socioeconomic systems-undermines our ability to sustainably manage global stocks of natural capital. Here we describe a novel concept and accompanying methodology (relating the adult body mass of terrestrial species to their requirements for land area, water, and energy) to quantify the natural capital needed to support terrestrial species within ecosystems, analogous to how natural capital use by humans is quantified in a socioeconomic context. We apply this methodology to quantify the amount of natural capital needed to support species observed using a specific surveyed site in Scotland. We find that the site can support a larger assemblage of species than those observed using the site; a primary aim of the rewilding project taking place there. This method conceptualises, for the first time, a comprehensive "dual-system" approach: modelling natural capital use in socioeconomic-and eco-systems simultaneously. It can facilitate the management of natural capital at the global scale, and in both the conservation and creation (e.g., rewilding) of biodiversity within managed ecosystems, representing an advancement in determining what socioeconomic trade-offs are needed to achieve contemporary conservation targets alongside ongoing human development.

Published
2022

21. Supplementary material to "Simulating marine neodymium isotope distributions using ND v1.0 coupled to the ocean component of the FAMOUS-MOSES1 climate model: sensitivities to reversible scavenging efficiency and benthic source distributions"

Author

Robinson, Suzanne, primary, Ivanovic, Ruza, additional, Gregoire, Lauren, additional, Tindall, Julia, additional, van de Flierdt, Tina, additional, Plancherel, Yves, additional, Pöppelmeier, Frerk, additional, Tachikawa, Kazuyo, additional, and Valdes, Paul, additional

Published
2022
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22. Simulating marine neodymium isotope distributions using ND v1.0 coupled to the ocean component of the FAMOUS-MOSES1 climate model: sensitivities to reversible scavenging efficiency and benthic source distributions

Author

Robinson, Suzanne, primary, Ivanovic, Ruza, additional, Gregoire, Lauren, additional, Tindall, Julia, additional, van de Flierdt, Tina, additional, Plancherel, Yves, additional, Pöppelmeier, Frerk, additional, Tachikawa, Kazuyo, additional, and Valdes, Paul, additional

Published
2022
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29. A Bayesian approach for the modelling of material stocks and flows with incomplete data

Author

Wang, Junyang, Ray, Kolyan, Brito-Parada, Pablo, Plancherel, Yves, Bide, Tom, Mankelow, Joseph, Morley, John, Stegemann, Julia, and Myers, Rupert

Subjects
FOS: Computer and information sciences, Applications (stat.AP), Statistics - Applications
Abstract

Material Flow Analysis (MFA) is used to quantify and understand the life cycles of materials from production to end of use, which enables environmental, social and economic impacts and interventions. MFA is challenging as available data is often limited and uncertain, giving rise to an underdetermined system with an infinite number of solutions when attempting to calculate the values of all stocks and flows in the system. Bayesian statistics is an effective way to address these challenges as it rigorously quantifies uncertainty in the data and propagates it in a system flow model to provide the probabilities associated with model solutions. Furthermore, the Bayesian approach provides a natural way to incorporate useful domain knowledge about the system through the elicitation of the prior distribution. This paper presents a novel Bayesian approach to MFA. We propose a mass based framework that directly models the flow and change in stock variables in the system, including systems with simultaneous presence of stocks and disaggregation of processes. The proposed approach is demonstrated on a global aluminium cycle, under a scenario where there is a shortage of data, coupled with weakly informative priors that only require basic information on flows and change in stocks. Bayesian model checking helps to identify inconsistencies in the data, and the posterior distribution is used to identify the variables in the system with the most uncertainty, which can aid data collection. We numerically investigate the properties of our method in simulations, and show that in limited data settings, the elicitation of an informative prior can greatly improve the performance of Bayesian methods, including for both estimation accuracy and uncertainty quantification.

Published
2022
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30. Simulating neodymium isotopes in a general circulation model (FAMOUS): Exploring the role of non-conservative particle-seawater interactions in governing marine distributions

Author

Robinson, Suzanne, primary, Ivanovic, Ruza, additional, Gregoire, Lauren, additional, Tindall, Julia, additional, van de Flierdt, Tina, additional, Plancherel, Yves, additional, Pöppelmeier, Frerk, additional, Tachikawa, Kazuyo, additional, and Valdes, Paul, additional

Published
2022
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32. Optimisation of the marine Nd isotope scheme in the ocean component of the FAMOUS general circulation model.

Author

Robinson, Suzanne, Ivanovic, Ruza, Gregoire, Lauren, Astfalck, Lachlan, van de Flierdt, Tina, Plancherel, Yves, Pöppelmeier, Frerk, and Tachikawa, Kazuyo

Subjects
SEAWATER, NEODYMIUM isotopes, ADVECTION, EMULATION software, OCEAN
Abstract

The neodymium (Nd) isotope composition (εNd) of seawater can be used to trace large-scale ocean circulation features. Yet, due to the elusive nature of marine Nd cycling, particularly in discerning non-conservative particle-seawater interactions, there remains considerable uncertainty surrounding a complete description of marine Nd budgets. Here, we present an optimisation of the Nd isotope scheme within the fast coupled atmosphere-ocean general circulation model (FAMOUS), using a statistical emulator to explore the parametric uncertainty and optimal combinations of three key model inputs relating to: (1) the efficiency of reversible scavenging, (2) the magnitude of the seafloor benthic flux, and (3) a riverine source scaling, accounting for release of Nd from river sourced particulate material. Furthermore, a suite of sensitivity tests provide insight on the regional mobilisation and spatial extent (i.e., testing a margin-constrained versus a seafloor-wide benthic flux) of certain reactive sediment components. In the calibrated scheme, the global marine Nd inventory totals 4.27 × 1012 g and has a mean residence time of 727 years. Atlantic Nd isotope distributions are represented well, and the weak sensitivity of North Atlantic Deep Water to highly unradiogenic sedimentary sources implies an abyssal benthic flux is of secondary importance in determining the water mass εNd properties under the modern vigorous circulation condition. On the other hand, Nd isotope distributions in the North Pacific are 3 to 4 εNd-units too unradiogenic compared to water measurements, and our simulations indicate that a spatially uniform flux of bulk sediment εNd does not sufficiently capture the mobile sediment components interacting with seawater. Our results of sensitivity tests suggest that there are distinct regional differences in how modern seawater acquires its εNd signal, in part relating to the complex interplay of Nd addition and water advection. [ABSTRACT FROM AUTHOR]

Published
2022
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33. Simulating marine neodymium isotope distributions using ND v1.0 coupled to the ocean component of the FAMOUS-MOSES1 climate model: sensitivities to reversible scavenging efficiency and benthic source distributions.

Author

Robinson, Suzanne, Ivanovic, Ruza, Gregoire, Lauren, Tindall, Julia, van de Flierdt, Tina, Plancherel, Yves, Pöppelmeier, Frerk, Tachikawa, Kazuyo, and Valdes, Paul

Subjects
NEODYMIUM isotopes, ATMOSPHERIC models, GENERAL circulation model, OCEAN, SEAWATER composition, OCEAN circulation, CLIMATE sensitivity
Abstract

The neodymium (Nd) isotopic composition of seawater is a widely used ocean circulation tracer. However, uncertainty in quantifying the global ocean Nd budget, particularly constraining elusive non-conservative processes, remains a major challenge. A substantial increase in modern seawater Nd measurements from the GEOTRACES programme coupled with recent hypotheses that a seafloor-wide benthic Nd flux to the ocean may govern global Nd isotope distributions (eNd) presents an opportunity to develop a new scheme specifically designed to test these paradigms. Here, we present the implementation of Nd isotopes (143Nd and 144Nd) into the ocean component of the FAMOUS coupled atmosphere-ocean general circulation model (ND v1.0), a tool which can be widely used for simulating complex feedbacks between different Earth system processes on decadal to multi-millennial timescales. Using an equilibrium pre-industrial simulation tuned to represent the largescale Atlantic Ocean circulation, we perform a series of sensitivity tests evaluating the new Nd isotope scheme. We investigate how Nd source/sink and cycling parameters govern global marine eNd distributions, and provide an updated compilation of 6,048 Nd concentration and 3,278 eNd measurements to assess model performance. Our findings support the notions that reversible scavenging is a key process for enhancing the Atlantic-Pacific basinal eNd gradient, and is capable of driving the observed increase in Nd concentration along the global circulation pathway. A benthic flux represents a major source of Nd to the deep ocean. However, model-data disparities in the North Pacific highlight that the source of eNd from seafloor sediment is too unradiogenic in our model with a constant benthic flux. Additionally, model-data mismatch in the northern North Atlantic suggests a missing source of Nd that is much more unradiogenic than the bulk sediment, alluding to the possibility of preferential contributions from 'reactive' detrital sediments under a benthic flux driven model of marine Nd cycling. The new Nd isotope scheme forms an excellent tool for exploring global marine Nd cycling and the interplay between climatic and oceanographic conditions under both modern and palaeoceanographic contexts. [ABSTRACT FROM AUTHOR]

Published
2022
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35. Global continental and marine detrital εNd: An updated compilation for use in understanding marine Nd cycling

Author

Barcelona Supercomputing Center, Robinson, Suzanne, Ivanovic, Ruza, Flierdt, Tina van de, Blanchet, Cécile L., Tachikawa, Kazuyo, Martin, Ellen E., Cook (Falco), Carys P., Williams, Trevor, Gregoire, Lauren, Plancherel, Yves, Arsouze, Thomas, Barcelona Supercomputing Center, Robinson, Suzanne, Ivanovic, Ruza, Flierdt, Tina van de, Blanchet, Cécile L., Tachikawa, Kazuyo, Martin, Ellen E., Cook (Falco), Carys P., Williams, Trevor, Gregoire, Lauren, Plancherel, Yves, and Arsouze, Thomas

Abstract

Understanding the role of sediment-water interactions in the oceanic cycling of neodymium (Nd) isotopes is essential for its reliable use as a modern and palaeoceanographic tracer of ocean circulation. However, the exact processes that control Nd cycling in the ocean are poorly defined and require an up-to-date knowledge of the sources, sinks and transformation of this tracer to and within the ocean (e.g. as per the GEOTRACES core mission). We propose a considerable improvement of Nd-source identification by providing an extensive and up-to-date compilation of published terrestrial and marine sedimentary Nd isotopic measurements. From this database, we construct high resolution, gridded, global maps that characterise the Nd-isotopic signature of the continental margins and seafloor sediment. Here, we present the database, interpolation methods, and final data products. Consistent with the previous studies that inform our compilation, our global results show unradiogenic detrital Nd isotopic values (εNd ≈ -20) in the North Atlantic, εNd values of ≈ -12 to -7 in the Indian and Southern Ocean, and radiogenic values (εNd ≈ -3 to +4) in the Pacific. The new, high-resolution interpolation is useful for improving conceptual knowledge of Nd sources and sinks and enables the application of isotope-enabled ocean models to understand targeted Nd behaviour in the oceans. Such applications may include: examining the strength and distribution of a possible benthic flux required to reconcile global Nd budgets, establishing the potential use of Nd isotopes as a kinematic tracer of ocean circulation, and a general quantification of the non-conservative sedimentary processes that may contribute to marine Nd cycling., SMR was funded by the Natural Environment Research Council (NERC) SPHERES Doctoral Training Partnership (grant number: NE/L002574/1). We thank April Abbott, Jianghui Du and Andy Ridgwell for informative discussions while undertaking the work. We are grateful to two anonymous reviewers for prompt and helpful comments that improved the manuscript, and to Karen H. Johannesson for swift editorial handling., Postprint (published version)

Published
2021

38. Particle-seawater interaction of neodymium in the North Atlantic

Author

Stichel, Torben, Kretschmer, Sven, Geibert, Walter, Lambelet, Myriam, Plancherel, Yves, Rutgers van der Loeff, Michiel, van de Flierdt, Tina, Stichel, Torben, Kretschmer, Sven, Geibert, Walter, Lambelet, Myriam, Plancherel, Yves, Rutgers van der Loeff, Michiel, and van de Flierdt, Tina

Abstract

Dissolved neodymium (Nd) isotopes (expressed as εNd) have been widely used as a water mass tracer in paleoceanography. However, one aspect of the modern biogeochemical cycle of Nd that has been sparsely investigated is the interplay between dissolved and particulate phases in seawater. We here present the first regional data set on particulate Nd isotope compositions (εNdp) and concentrations ([Nd]p) from five stations in the western North Atlantic Ocean along the GEOTRACES GA02 transect, in conjunction with previously published dissolved Nd isotope compositions (εNdd) and concentrations ([Nd]d)1. Key observations and interpretations from our new particulate data set include the following: (1) A low fractional contributions of [Nd]p to the total Nd inventory per volume unit of seawater (~5%), with significant increases of up to 45% in benthic boundary layers. (2) Increasing Nd concentrations in suspended particulate matter ([Nd]SPM) and fractions of lithogenic material with water depth, suggesting the removal of Nd poor phases. (3) Different provenances of particulates in the subpolar and subtropical gyres as evidenced by their Nd isotope fingerprints reaching from εNdp ≈ -20 near the Labrador Basin (old continental crust), over εNdp ≈ -4 between Iceland and Greenland (young mafic provenance), to values of εNdp ≈-13 in the subtropics (similar to African dust signal). (4) Vertical heterogeneity of εNdp, as well as large deviations from ambient seawater values in the subpolar gyre, indicate advection of lithogenic particles in this area. (5) Vertically homogenous εNdp values in the subtropical gyre, indistinguishable from εNdd values, are indicative of predominance of vertical particulate supply. The process of reversible scavenging only seems to influence particulate signatures below 3 km. Overall, we do not find evidence on enhanced particle dissolution, often invoked to explain the observed increase in dissolved Nd in the North Atlantic.

Published
2020

40. Global continental and marine detrital εNd: an updated compilation for use in understanding marine Nd cycling

Author

Robinson, Suzanne, primary, Ivanovic, Ruza, additional, van de Flierdt, Tina, additional, Blanchet, Cecile, additional, Tachikawa, Kazuyo, additional, Martin, Ellen, additional, Cook (Falco), Carys, additional, Williams, Trevor, additional, Gregoire, Lauren, additional, Plancherel, Yves, additional, Jeandel, Catherine, additional, and Arsouze, Thomas, additional

Published
2021
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42. Nearshore Tsunami amplitudes across the Maldives archipelago due to worst case seismic scenarios in the Indian Ocean.

Author

Rasheed, Shuaib, Warder, Simon C., Plancherel, Yves, and Piggott, Matthew D.

Subjects
TSUNAMIS, TERRITORIAL waters, ARCHIPELAGOES, OCEAN, WAVE diffraction, CORAL reefs & islands, RISK assessment
Abstract

The Maldives face the threat of tsunamis from a multitude of sources. However, the limited availability of critical data, such as bathymetry (a recurrent problem for many island nations), has meant that the impact of these threats has not been studied at an island scale. Studies of tsunami propagation at the island scale but across multiple Atolls is also a challenging task due to the large domain and high resolution required for modelling. Here we use a high resolution bathymetry dataset of the Maldives archipelago, and corresponding high numerical model resolution, to carry out a scenario-based tsunami hazard assessment for the entire Maldives archipelago to investigate the potential impact of plausible far-field tsunamis across the Indian Ocean at the island scale. The results indicate that the bathymetry of the Atolls, which are characterized by very steep boundaries offshore, is extremely efficient in absorbing and redirecting incoming tsunami waves. Results also highlight the importance that local effects have in modulating tsunami amplitude nearshore, including the location of the Atoll in question, the location of a given island within the Atoll, and the distance of that island to the reef, as well as a variety of other factors. We also find that the refraction and diffraction of tsunami waves within individual Atolls contribute to the maximum tsunami amplitude patterns observed across the islands in the Atolls. The findings from this study contribute to a better understanding of tsunamis across complex Atoll systems, and will help decision and policy makers in the Maldives asses the potential impact of tsunamis across individual islands. An online tool is provided which presents users with a simple interface allowing the wider community to browse the simulation results presented here and assess the potential impact of tsunamis at the local scale. [ABSTRACT FROM AUTHOR]

Published
2022
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47. The large-scale evolution of neodymium isotopic composition in the global modern and Holocene ocean revealed from seawater data and other records

Author

Kazuyo, Tachikawa, Arsouze, Thomas, Bayon, Germain, Bory, Aloys, Colin, Christophe, Dutay, Jean-Claude, Frank, Norbert, Giraud, Xavier, Gourlan, Alexandra T., Jeandel, Catherine, Lacan, François, Meynadier, Laure, Montagna, Paolo, Piotrowski, Alexander M., Plancherel, Yves, Pucéat, Emmanuelle, Roy-Barman, Matthieu, Waelbroeck, Claire, Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), École Nationale Supérieure de Techniques Avancées (ENSTA Paris), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Laboratoire d’Océanologie et de Géosciences (LOG) - UMR 8187 (LOG), Institut national des sciences de l'Univers (INSU - CNRS)-Université du Littoral Côte d'Opale (ULCO)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Nord]), Géosciences Paris Saclay (GEOPS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institute of Environmental Physics [Heidelberg] (IUP), Universität Heidelberg [Heidelberg] = Heidelberg University, Institut des Sciences de la Terre (ISTerre), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Laboratoire d'études en Géophysique et océanographie spatiales (LEGOS), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Institut de Physique du Globe de Paris (IPG Paris), Istituto di Scienze Marine [Bologna] (ISMAR), Istituto di Science Marine (ISMAR ), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR)-National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Department of Earth Sciences [University of Cambridge], University of Cambridge [UK] (CAM), Department of Earth Sciences [Oxford], University of Oxford, Biogéosciences [UMR 6282] (BGS), Université de Bourgogne (UB)-Centre National de la Recherche Scientifique (CNRS), and Tachikawa, Kazuyo

Subjects
[SDU.STU] Sciences of the Universe [physics]/Earth Sciences, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences
Abstract

International audience; The large-scale evolution of neodymium isotopic composition in the global modern and Holocene ocean revealed from seawater data and other records. Kazuyo Tachikawa and project members Neodymium isotopic compositions (143 Nd/ 144 Nd or ε Nd) have been used as a tracer of water masses and lithogenic inputs to the ocean. To further evaluate the faithfulness of this tracer, we have updated a global seawater ε Nd database and combined it with hydrography parameters (temperature, salinity, nutrients and oxygen concentrations), carbon isotopic ratio and radiocarbon of dissolved inorganic carbon. Archive ε Nd data are compiled for leachates, foraminiferal tests, deep-sea corals and fish teeth/debris from the Holocene period. At water depths ≥ 1500m, property-property plots show clear correlations between seawater ε Nd and the other variables, suggesting that large-scale water mass mixing is a primary control of deepwater ε Nd distribution. At ≥ 200m, basin-scale seawater T-S-ε Nd diagrams demonstrate the isotopic evolution of different water masses. Seawater and archive ε Nd values are compared using property-property plots and T-S-ε Nd diagrams. Archive values generally agree with corresponding seawater values although they tend to be at the upper limit in the Pacific. Both positive and negative offsets exist in the northern North Atlantic. Applying multiple regression analysis to deep (≥ 1500m) seawater data, we established empirical equations that predict the main, large-scale, deepwater ε Nd trends from hydrography parameters. Large offsets from the predicted values are interpreted as a sign of significant local/regional influence. Dominant continental influence on seawater and archive ε Nd is observed mainly within 1,000 km from the continents. Generally, seawater and archive ε Nd values form gradual latitudinal trend in the Atlantic and Pacific at depths ≥ 600m, consistent with the idea that Nd isotopes help distinguish between northern/southern sourced water contributions at intermediate and deep water depths.

Published
2017

48. Response of tidal flow regime and sediment transport in North Male' Atoll, Maldives to coastal modification and sea level rise.

Author

Rasheed, Shuaib, Warder, Simon C., Plancherel, Yves, and Piggott, Matthew D.

Subjects
SEDIMENT transport, SEA level, PARTICLE size distribution, COASTAL changes, COASTAL sediments, SODIC soils, RECLAMATION of land, CORAL reefs & islands
Abstract

Changes to coastlines and bathymetry alter tidal dynamics and associated sediment transport process, impacting upon a number of threats facing coastal regions, including flood risk and erosion. Especially vulnerable are coral atolls such as those that make up the Maldives archipelago which has undergone significant land reclamation in recent years and decades, and is also particularly exposed to sea level rise. Here we develop a tidal model of Male' Atoll, Maldives, and use it to assess potential changes to sediment grain size distributions under sea level rise and coastline alteration scenarios. The results indicate that the impact of coastline modification over the last two decades at the island scale is not limited to the immediate vicinity of the modified island, but can also significantly impact the sediment grain size distribution across the wider atoll basin. Additionally, the degree of change in sediment distribution which can be associated with sea level rise that is projected to occur over relatively long time periods is predicted to occur over far shorter time periods with coastline changes, highlighting the need to better understand, predict and mitigate the impact of land reclamation and other coastal modifications before conducting such activities. [ABSTRACT FROM AUTHOR]

Published
2020
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50. The potential of sedimentary foraminiferal rare earth element patterns to trace water masses in the past

Author

Osborne, Anne Helen, Hathorne, Ed C., Schijf, Johan, Plancherel, Yves, Böning, Philipp, Frank, Martin, Osborne, Anne Helen, Hathorne, Ed C., Schijf, Johan, Plancherel, Yves, Böning, Philipp, and Frank, Martin

Abstract

Dissolved rare earth element (REE) concentration data from intermediate and deep seawater form an array characterized by higher middle REE enrichments (MREE/MREE*) in the North Atlantic and a progressive increase in heavy-to-light REE ratios (HREE/LREE) as water masses age. The REEs in foraminifera are fractionated towards higher MREE/MREE* and lower HREE/LREE relative to seawater. Calculations based on a scavenging model show that the REE patterns in uncleaned core-top foraminifera resemble those adsorbed onto calcite, particulate organic material, and hydrous ferric oxides but the full extent of the REE fractionation measured in foraminifera was not reproduced by the model. However, differences in the HREE/LREE, MREE/MREE* ratios and the cerium anomaly between ocean basins are preserved and are in agreement with the seawater REE distribution. Under oxic conditions, the HREE/LREE and MREE/MREE* compositions of uncleaned foraminifera at the sediment/seawater boundary are preserved during burial but the cerium anomaly is sensitive to burial depth. In suboxic sedimentary environments, all uncleaned foraminiferal REE concentrations are elevated relative to core-top values indicating addition of REEs from pore waters. The HREE/LREE ratio is highest when sedimentation rates were greatest [Lippold et al., 2009] and when high Fe/Ca ratios in the uncleaned foraminifera indicate that Fe was mobile. In sediments that have not experienced suboxic conditions during burial, uncleaned foraminifera preserve the seawater signal taken up at the sediment/seawater interface and are therefore suggested to be a suitable archive of changes in the REE signal of past bottom waters. This article is protected by copyright. All rights reserved.

Published
2017
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