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Introduction
Publications
Publications (264)
Merritts et al. (2023) misrepresent Paul Crutzen’s Anthropocene concept as encompassing all significant anthropogenic impacts, extending back many millennia. Crutzen’s definition reflects massively enhanced, much more recent human impacts that transformed the Earth System away from the stability of Holocene conditions.
His concept of an epoch (henc...
Event stratigraphy is used to help characterise the Anthropocene as a chronostratigraphic concept, based on analogous deep-time events, for which we provide a novel categorization. Events in stratigraphy are distinct from extensive, time-transgressive ‘episodes’ – such as the global, highly diachronous record of anthropogenic change, termed here an...
Despite its major role in the Earth’s climate regulation, the evolution of high-latitude ocean dynamics through geological time remains unclear. Around Antarctica, changes in the Southern Ocean (SO) circulation are inferred to be responsible for cooling from the late Eocene and glaciation in the early Oligocene. Here, we present a geochemical study...
Event stratigraphy is used to help characterise the Anthropocene as a chronostratigraphic concept, based on analogous deep-time events, for which we provide a novel categorization. Events in stratigraphy are distinct from extensive, time-transgressive ‘episodes’ – such as the global, highly diachronous record of anthropogenic change, termed here an...
Event stratigraphy is used to help characterise the Anthropocene as a chronostratigraphic concept, based on analogous deep-time events, for which we provide a novel categorization. Events in stratigraphy are distinct from extensive, time-transgressive ‘episodes’ – such as the global, highly diachronous record of anthropogenic change, termed here an...
The Anthropocene defined as an epoch/series within the Geological Time Scale, and with an isochronous inception in the mid-20th century, would both utilize the rich array of stratigraphic signals associated with the Great Acceleration and align with Earth System science analysis from where the term Anthropocene originated. It would be stratigraphic...
Determining the factors controlling the neodymium (Nd) isotopic compositions (expressed as εNd) and rare earth element (REE) concentrations of rivers is imperative to improve our understanding of the distribution of these water mass tracers in the ocean. Here we present the first measurements of <0.45 μm-filtrate REE concentrations (i.e., the conce...
The Anthropocene was conceptualized in 2000 to reflect the extensive impact of human activities on our planet, and subsequent detailed analyses have revealed a sub- stantial Earth System response to these impacts begin- ning in the mid-20th century. Key to this understanding was the discovery of a sharp upturn in a multitude of global socio-economi...
The Isotrace CNRS workgroup in collaboration with National Research Council of Canada has characterized a number of trace element mass fractions and isotope ratios currently not certified in AQUA-1 natural drinking water reference material (NRC Canada). This survey further expands the use of this material as a tool for environmental quality control...
Total dissolvable and dissolved aluminum (TDAl, DAl) and manganese (TDMn, DMn) concentrations were measured at 12 stations in and around the Solomon Sea in 2012 as part of the GEOTRACES GP-12 cruise. These data were used to determine the potential for the Solomon Sea to act as a source of Al and Mn to the Equatorial Undercurrent (EUC). From a net b...
The establishment of the Antarctic Circumpolar Current (ACC) is one of the most important events for both global oceanic circulation and climate of the Cenozoic. The onset of this major current hinges on the opening of two major oceanic passages, the Drake Passage and the Tasmanian gateways that connect Pacific, Atlantic and Indian oceans allowing...
The term Anthropocene initially emerged from the Earth System science community in
the early 2000s, denoting a concept that the Holocene Epoch has terminated as a consequence of human activities. First associated with the onset of the Industrial Revolution, it was then more closely linked
with the Great Acceleration in industrialization and globali...
![Figure 2. (a) Vertical profiles of particulate [Ce] concentrations...](profile/Marion-Lagarde/publication/346202540/figure/fig2/AS:961336112607286@1606211798985/a-Vertical-profiles-of-particulate-Ce-concentrations-superimposed-on-salinity-S_Q320.jpg)
Particulate concentrations of the 14 Rare Earth Elements (PREE), yttrium, and 232-thorium were measured in 200 samples collected in the epipelagic (ca. 0–200 m) and mesopelagic (ca. 200–1500 m) zones of the North Atlantic during the GEOVIDE cruise (May/June 2014, R/V
Pourquoi Pas?, GEOTRACES GA01), providing the most detailed snapshot of the
PREE d...
The southern westerly winds (SWW) play a major role in climate variability in Southern Hemisphere mid-and high-latitudes, regulating rainfall, ocean circulation, and the Southern Ocean carbon sink. Despite their importance, little is known about millennial scale changes in the SWW and how they have influenced the climate system in the past and inte...
Particulate concentrations of the fourteen Rare Earth Elements (PREE), yttrium and 232-thorium have been measured in two hundred samples collected in the epipelagic (ca. 0–200 m) and the mesopelagic (ca. 200–1000 m) zones of the North Atlantic, during the GEOVIDE cruise (May/June 2014, R/V Pourquoi Pas ?, GEOTRACES GA01). Particulate cerium (PCe) c...
Elemental concentrations of Rare Earth Elements (REE) and isotopic compositions of Neodymium (εNd) have been measured in three water column profiles in the North Western Mediterranean Sea. Clear enrichments of REE are observed when comparing to adjacent Atlantic waters suggesting REE inputs along the circulation in this area. For the first time, re...
The distributions of dissolved and particulate thorium isotopes (²³⁰Th and ²³²Th) were established in samples from the BONUS GoodHope (BGH) IPY-GEOTRACES cruise in the SE Atlantic sector of the Southern Ocean (36°S-13°E to 57°S-0°, Feb.–Mar. 2008). The distribution of total (dissolved + particulate) ²³²Th is dominated by the inputs from continental...
The Anthropocene, a term launched into public debate by Nobel Prize winner Paul Crutzen, has been used informally to describe the time period during which human actions have had a drastic effect on the Earth and its ecosystems. This book presents evidence for defining the Anthropocene as a geological epoch, written by the high-profile international...
The GEOVIDE cruise, a collaborative project within the framework of the
international GEOTRACES programme, was conducted along the French-led section
in the North Atlantic Ocean (Section GA01), between 15 May and 30 June 2014.
In this special issue (https://www.biogeosciences.net/special_issue900.html), results from GEOVIDE, including physical ocea...
Distributions of dissolved rare earth element (REE) concentrations and neodymium isotopic compositions (expressed as eNd) of seawater over and off the Kerguelen Plateau in the Southern Ocean are presented. The sampling took place during the austral spring bloom in October-November 2011 (KEOPS2 project, GEOTRACES process study) and aimed to further...
The GEOVIDE cruise, a collaborative project within the framework of the international GEOTRACES programme, was conducted along the French-led section in the North Atlantic Ocean (Section GA01), between 15 May and 30 June 2014. In this Special Issue, results from GEOVIDE, including physical oceanography and trace element and isotope cyclings, are pr...
The GEOTRACES Intermediate Data Product 2017 (IDP2017) is the second publicly available data product of the international GEOTRACES programme, and contains data measured and quality controlled before the end of 2016. The IDP2017 includes data from the Atlantic, Pacific, Arctic, Southern and Indian oceans, with about twice the data volume of the pre...
The GEOTRACES Intermediate Data Product 2017 (IDP2017) is the second publicly available data product of the international GEOTRACES programme, and contains data measured and quality controlled before the end of 2016. The IDP2017 includes data from the Atlantic, Pacific, Arctic, Southern and Indian oceans, with about twice the data volume of the pre...
We report detailed sections of radium-226
(226Ra, T1∕2 = 1602 years) activities and barium (Ba)
concentrations determined in the North Atlantic (Portugal–Greenland–Canada)
in the framework of the international GEOTRACES program (GA01 section –
GEOVIDE project, May–July 2014). Dissolved 226Ra and Ba are strongly
correlated along the section, a patte...
The Anthropocene as a potential new unit of the International Chronostratigraphic Chart (which serves as the basis of the Geological Time Scale) is assessed in terms of the stratigraphic markers and approximate boundary levels available to define the base of the unit. The task of assessing and selecting potential Global Boundary Stratotype Section...
The Anthropocene, as a potential new unit of the International Chronostratigraphic Chart, is assessed in terms of stratigraphic markers and approximate boundary levels available to define the unit base. The task of assessing and selecting potential GSSP candidate sections, a requirement in seeking formalisation of the term, is being actively pursue...
This is the link to the press release from University of Leicester for the new AWG paper authored by the above members of the working group: https://www2.le.ac.uk/offices/press/press-releases/2017/march/the-anthropocene-scientists-respond-to-criticisms-of-a-new-geological-epoch
A range of published arguments against formalizing the Anthropocene as a geological time unit have variously suggested that it is a misleading term of non-stratigraphic origin and usage, is based on insignificant temporal and material stratigraphic content unlike that used to define older geological time units, is focused on observation of human hi...
Quantifying fluxes of trace elements and their isotopes (TEIs) at the ocean's sediment–water boundary is a pre-eminent challenge to understand their role in the present, past and future ocean. There are multiple processes that drive the uptake and release of TEIs, and properties that determine their rates are unevenly distributed (e.g. sediment com...
Land to ocean transfer of material largely controls the chemical composition of seawater and the global element cycles. Oceanic isotopic budgets of chemical species, macro- and micronutrients (e.g. Nd, Sr, Si, Mg, Zn, Mo and Ni) have revealed an imbalance between their sources and sinks. Radiogenic isotope budgets underlined the importance of takin...
![Figure 4. (a) Amazon estuary [Nd] from Sholkovitz [70] (circles) and...](publication/310952743/figure/fig4/AS:812478833364999@1570721457897/a-Amazon-estuary-Nd-from-Sholkovitz-70-circles-and-Rousseau-et-al-13_Q320.jpg)
Continental shelves and shelf seas play a central role in the global carbon cycle. However, their importance with respect to trace element and isotope (TEI) inputs to ocean basins is less well understood. Here, we present major findings on shelf TEI biogeochemistry from the GEOTRACES programme as well as a proof of concept for a new method to estim...
Quantifying trace element and isotope fluxes at the ocean-sediment boundary - supplementary material
We assess the scale and extent of the physical technosphere, defined here as the summed material output of the contemporary human enterprise. It includes active urban, agricultural and marine components, used to sustain energy and material flow for current human life, and a growing residue layer, currently only in small part recycled back into the...
Atmospheric mineral dust is intrinsically linked with climate. Although dust flux variability on glacial–interglacial timescales is well documented, Holocene dust records remain scarce. To fill this gap, we conducted elemental, isotopic and sedimentological analyses on a peat core from the Karukinka Natural Park in Tierra del Fuego. An 8000-year-ol...
An extensive compilation of published neodymium (Nd) concentrations and isotopic compositions (Nd IC) was realized in order to establish a new database and a map (using a high-resolution geological map of the area) of the distribution of these parameters for all the Mediterranean margins. Data were extracted from different kinds of samples: river s...
Marine geochemistry uses chemical elements and their isotopes to study how the ocean works in terms of ocean circulation, chemical composition, biological activity and atmospheric CO2 regulation. This rapidly growing field is at a crossroad for many disciplines (physical, chemical and biological oceanography, geology, climatology, ecology, etc.). I...
Marine geochemistry uses chemical elements and their isotopes to study how the ocean works in terms of ocean circulation, chemical composition, biological activity and atmospheric CO2 regulation. This rapidly growing field is at a crossroad for many disciplines (physical, chemical and biological oceanography, geology, climatology, ecology, etc.). I...
Marine geochemistry uses chemical elements and their isotopes to study how the ocean works. It brings quantitative answers to questions such as: What is the deep ocean mixing rate? How much atmospheric CO2 is pumped by the ocean? How fast are pollutants removed from the ocean? How do ecosystems react to the anthropogenic pressure? The book provides...
Marine geochemistry uses chemical elements and their isotopes to study how the ocean works. It brings quantitative answers to questions such as: What is the deep ocean mixing rate? How much atmospheric CO2 is pumped by the ocean? How fast are pollutants removed from the ocean? How do ecosystems react to the anthropogenic pressure? The book provides...
Marine geochemistry uses chemical elements and their isotopes to study how the ocean works. It brings quantitative answers to questions such as: What is the deep ocean mixing rate? How much atmospheric CO2 is pumped by the ocean? How fast are pollutants removed from the ocean? How do ecosystems react to the anthropogenic pressure? The book provides...
Marine geochemistry uses chemical elements and their isotopes to study how the ocean works. It brings quantitative answers to questions such as: What is the deep ocean mixing rate? How much atmospheric CO2 is pumped by the ocean? How fast are pollutants removed from the ocean? How do ecosystems react to the anthropogenic pressure? The book provides...
Marine geochemistry uses chemical elements and their isotopes to study how the ocean works. It brings quantitative answers to questions such as: What is the deep ocean mixing rate? How much atmospheric CO2 is pumped by the ocean? How fast are pollutants removed from the ocean? How do ecosystems react to the anthropogenic pressure? The book provides...
Marine geochemistry uses chemical elements and their isotopes to study how the ocean works. It brings quantitative answers to questions such as: What is the deep ocean mixing rate? How much atmospheric CO2 is pumped by the ocean? How fast are pollutants removed from the ocean? How do ecosystems react to the anthropogenic pressure? The book provides...
Marine geochemistry uses chemical elements and their isotopes to study how the ocean works. It brings quantitative answers to questions such as: What is the deep ocean mixing rate? How much atmospheric CO2 is pumped by the ocean? How fast are pollutants removed from the ocean? How do ecosystems react to the anthropogenic pressure? The book provides...
Marine geochemistry uses chemical elements and their isotopes to study how the ocean works. It brings quantitative answers to questions such as: What is the deep ocean mixing rate? How much atmospheric CO2 is pumped by the ocean? How fast are pollutants removed from the ocean? How do ecosystems react to the anthropogenic pressure? The book provides...
Marine geochemistry uses chemical elements and their isotopes to study how the ocean works. It brings quantitative answers to questions such as: What is the deep ocean mixing rate? How much atmospheric CO2 is pumped by the ocean? How fast are pollutants removed from the ocean? How do ecosystems react to the anthropogenic pressure? The book provides...
Marine geochemistry uses chemical elements and their isotopes to study how the ocean works. It brings quantitative answers to questions such as: What is the deep ocean mixing rate? How much atmospheric CO2 is pumped by the ocean? How fast are pollutants removed from the ocean? How do ecosystems react to the anthropogenic pressure? The book provides...
Marine geochemistry uses chemical elements and their isotopes to study how the ocean works. It brings quantitative answers to questions such as: What is the deep ocean mixing rate? How much atmospheric CO2 is pumped by the ocean? How fast are pollutants removed from the ocean? How do ecosystems react to the anthropogenic pressure? The book provides...
Stratigraphy provides insights into the evolution and dynamics of the Earth System over
its long history. With recent developments in Earth System science, changes in Earth System dynamics can now be observed directly and projected into the near future. An integration of the two approaches provides powerful insights into the nature and significance...
An extensive compilation of published neodymium (Nd) concentrations and isotopic compositions (Nd IC) was realized in order to establish a new database and a map (using a high resolution geological map of the area) of the distribution of these parameters for all the Mediterranean margins. Data were extracted from different kinds of samples: river s...
The rise of plastics since the mid-20th century, both as a material element of modern life and as a growing environmental pollutant, has been widely described. Their distribution in both the terrestrial and marine realms suggests that they are a key geological indicator of the Anthropocene, as a distinctive stratal component. Most immediately evide...
Human activity is leaving a pervasive and persistent signature on Earth. Vigorous debate continues about whether this warrants recognition as a new geologic time unit known as the Anthropocene. We review anthropogenic markers of functional changes in the Earth system through the stratigraphic record. The appearance of manufactured materials in sedi...
Description and derivation of equation used to derive trace element and isotope fluxes from the continental margin
Descriptive details of the aluminium model presented in Homoky et al (2016), Quantifying trace element and isotope fluxes at the ocean-sediment boundary - a review, Phil. Trans. Royal Soc. A.
Description and derivation of equation used to derive trace element and isotope fluxes from the continental margin
Descriptive details of the aluminium model presented in Homoky et al (2016), Quantifying trace element and isotope fluxes at the ocean-sediment boundary - a review, Phil. Trans. Royal Soc. A.
Indispensable à la régulation du climat, au développement de la vie sur Terre, au maintien des écosystèmes, aux populations, au développement de l’agriculture, de l’industrie comme à la production d’énergie, l’eau est un élément vital. Il convient donc, dans un contexte de changement global, d’analyser dans toute sa diversité la place et le rôle de...
A recently published analysis by Lewis and Maslin (Lewis SL and Maslin MA (2015) Defining the Anthropocene. Nature 519: 171–180) has identified two new potential horizons for the Holocene−Anthropocene boundary: 1610 (associated with European colonization of the Americas), or 1964 (the peak of the excess radiocarbon signal arising from atom bomb tes...
Rare earth element (REE) concentrations and neodymium isotopic composition (ɛNd) are tracers for ocean circulation and biogeochemistry. Although models suggest that REE release from lithogenic sediment in river discharge may dominate all other REE inputs to the oceans, the occurrence, mechanisms and magnitude of such a source are still debated. Her...
Many scientists are making the case that humanity is living in a new geological epoch, the Anthropocene, but there is no agreement yet as to when this epoch began. The start might be defined by a historical event, such as the beginning of the fossil-fueled Industrial Revolution or the first nuclear explosion in 1945. Standard stratigraphic practice...
As members of the Anthropocene Working Group, we contend that the proposed new geological epoch should reflect a unique stratigraphic unit that is characterized by unambiguous, widespread and essentially permanent anthropogenic signatures in rock, glacial ice or marine sediments. We therefore find the two dates chosen by Simon Lewis and Mark Maslin...
The GEOTRACES Intermediate Data Product 2014 (IDP2014) is the first publicly available data product of the international GEOTRACES programme, and contains data measured and quality controlled before the end of 2013. It consists of two parts: (1) a compilation of digital data for more than 200 trace elements and isotopes (TEIs) as well as classical...
Neodymium isotopic composition (Nd IC) is a tracer of oceanic circulation and lithogenic inputs to the ocean. An extensive compilation of published Nd isotopic values was realized in order to establish a database and a map of Nd and Nd concentrations characterizing all the Mediterranean margins. This was built based on different kinds of samples: r...
Cet article présente les mode de gestion en France et leur évolution. Il montre que l'équilibre entre gestion publique et privée a été fluctuant au cours du temps et que dans tous les cas, la responsabilité de la collectivité dans l’organisation du service est importante.