Article
Geochemistry & Geophysics
Ruixia Bai, Matthew G. Jackson, Fang Huang, Frederic Moynier, Gabriel Devos, Saemundur A. Halldorsson, Lorraine Lisiecki, Haoming Yin, Yihang Peng, Xiaoyun Nan
Summary: The study investigated the characteristic of barium isotopic compositions in ocean island basalts (OIB), revealing the presence of recycled crust in the mantle based on the variations in barium isotopic compositions among different OIB sources. By analyzing a variety of lava samples, correlations and potential mixing mechanisms were revealed among them.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2022)
Article
Geosciences, Multidisciplinary
Maoliang Zhang, Wei Liu, Lufeng Guan, Naoto Takahata, Yuji Sano, Ying Li, Xiaocheng Zhou, Zhi Chen, Chunhui Cao, Lihong Zhang, Yun-Chao Lang, Cong-Qiang Liu, Sheng Xu
Summary: This study examines hydrothermal helium degassing in the Simao block and provides flux estimates for He-3 and He-4. It finds that in this continental collision setting, mantle helium fluxes are 2-3 orders of magnitude greater than those of stable continents. The high mantle helium fluxes and He-3/He-4 ratios are attributed to recent magma recharge and active tectonics driven by the India-Asia continental collision.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Geochemistry & Geophysics
Caroline R. Soderman, Simon Matthews, Oliver Shorttle, Matthew G. Jackson, Saskia Ruttor, Oliver Nebel, Simon Turner, Christoph Beier, Marc-Alban Millet, Elisabeth Widom, Munir Humayun, Helen M. Williams
Summary: The study investigates the components from the mantle and crust in the sources of ocean island basalts using iron isotope data. The results indicate that heavy iron isotopes are correlated with radiogenic isotope signatures of enriched crustal material, rather than the involvement of the Earth's core. The generation of heavy delta Fe-57 melts in OIB requires various complex processes.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2021)
Article
Geochemistry & Geophysics
K. J. Walowski, L. A. Kirstein, J. C. M. De Hoog, T. Elliott, I. P. Savov, R. E. Jones
Summary: The study presents the largest and most precise boron isotope dataset from ocean island basalt glasses and olivine-hosted melt inclusions, revealing the characteristics of volatile elements in the mantle and the processes generating different mantle reservoirs. It suggests that the deep mantle is becoming increasingly depleted in boron over time and highlights the decoupling of boron isotopes from radiogenic isotopes, providing a new perspective on volatile recycling.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2021)
Article
Geochemistry & Geophysics
Frank J. Pavia, Emily H. G. Cooperdock, Juan Carlos de Obeso, Kenneth W. W. Sims, Francois L. H. Tissot, Frieder Klein
Summary: The aqueous alteration of mantle rocks plays a key role in Earth's global biogeochemical cycling. This study uses uranium isotopes to investigate the weathering of subaerial and submarine serpentinites, finding that uranium isotopes are sensitive to post-serpentinization weathering processes and can provide information about fluid sources. The results suggest that serpentinites from different environments have different uranium isotopic compositions, reflecting variations in protolith composition and weathering processes. This research is important for understanding Earth's elemental cycling.
EARTH AND PLANETARY SCIENCE LETTERS
(2023)
Article
Geochemistry & Geophysics
Peter L. Olson, Zachary D. Sharp
Summary: Volatile substances from the solar nebula can be found in Earth's deep mantle, and there is a possibility that the core also contains volatile substances from the solar nebula, although the amount is unknown. In this study, calculations of volatile ingassing and degassing are used to estimate the abundance of primordial He-3 in the core and to track the rate of He-3 exchange between the core and mantle throughout Earth's history.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2022)
Article
Multidisciplinary Sciences
David Bekaert, Esteban Gazel, Stephen Turner, Mark D. Behn, J. Marten de Moor, Sabin Zahirovic, Vlad C. Manea, Kaj Hoernle, Tobias P. Fischer, Alexander Hammerstrom, Alan M. Seltzer, Justin T. Kulongoski, Bina S. Patel, Matthew O. Schrenk, Saemundur A. Halldorsson, Mayuko Nakagawa, Carlos J. Ramirez, John A. Krantz, Mustafa Yucel, Christopher J. Ballentine, Donato Giovannelli, Karen G. Lloyd, Peter H. Barry
Summary: Mantle plumes are known conduits for upwelling enriched material, but the extent of lateral flow processes dispersing mantle material far from vertical conduits remains unclear. Data from hydrothermal fluids in Central America show high He-3/He-4 values in Panama, likely derived from a Galapagos plume-like mantle infiltrating through a slab window. These findings suggest the potential for lateral mantle flow to transport geochemical heterogeneities over long distances.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Geochemistry & Geophysics
Caroline R. Soderman, Oliver Shorttle, Simon Matthews, Helen M. Williams
Summary: The geochemistry of global mantle melts shows lithological and temperature heterogeneities from both upper and lower mantle. Non-traditional stable isotopes are suggested as new tools for understanding mantle heterogeneity. Some stable isotope systems can be used as tracers of mantle temperature and lithological heterogeneity, but are not predicted to be sensitive to mantle potential temperature variations with current analytical precision.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2022)
Article
Geochemistry & Geophysics
Robert W. Nicklas, Alan D. Brandon, Tod E. Waight, Igor S. Puchtel, James M. D. Day
Summary: Ocean island basalts exhibit significant variations in isotopic compositions, indicating contributions from multiple mantle sources including ancient refractory sources and recycled oceanic crustal components. Different isotopic systems show correlations, such as between Os and Pb, implying binary mixing between depleted and enriched sources. The presence of highly depleted mantle sources and recycled oceanic crust components are identified, with implications for the origin and evolution of the Icelandic plume.
Article
Multidisciplinary Sciences
Guoxiong Chen, Qiuming Cheng, Timothy W. Lyons, Jun Shen, Frits Agterberg, Ning Huang, Molei Zhao
Summary: In this study, an independent approach using machine learning and global geochemical data was employed to explore the changes in atmospheric oxygen levels over the past 4.0 billion years. The results show a two-step increase in atmospheric oxygen similar to previously published curves, but with additional, more detailed fluctuations. These findings suggest that the oxygenation of Earth's atmosphere may be partially attributed to mantle cooling and the evolution of mantle melts.
NATURE COMMUNICATIONS
(2022)
Article
Geochemistry & Geophysics
Berengere Mougel, Arnaud Agranier, Christophe Hemond, Pascal Gente
Summary: By analyzing 52 basalt samples from the East Pacific Rise, this study identified two types of isotopic variability, attributed to continuous melting of the ambient mantle and the influence of seamount sources on the ridge. The research proposed a two-step hotspot-ridge interaction model to explain the evolution of basalt compositions in the region.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2021)
Article
Geochemistry & Geophysics
David W. Graham, Peter J. Michael, Thi B. Truong
Summary: We analyzed the carbon isotope composition of vesicle CO2, He isotopes and concentrations in basalts from Loihi Seamount, and found that alkali basalts have a wider range of carbon isotope composition compared to tholeiites and transitional basalts. The restricted range of carbon isotope values for Loihi basalts suggests a degassing process, but the similarity to other mantle-derived basalts presents a conundrum. The high carbon isotope values in Loihi basalts may be due to primordial carbon isotope heterogeneity, exchange of carbon at the core-mantle boundary, or the presence of recycled carbonate in the Hawaiian plume source region.
EARTH AND PLANETARY SCIENCE LETTERS
(2023)
Article
Geochemistry & Geophysics
Maja B. Rasmussen, Saemundur A. Halldorsson, Matthew G. Jackson, Ilya N. Bindeman, Martin J. Whitehouse
Summary: Icelandic basalts have low oxygen isotope (δO-18) values, which may be attributed to the combination of crustal assimilation and mantle characteristics, with the latter being more significant. Measurements and analysis of olivine crystals from the Iceland hotspot, covering 16 Ma of activity, reveal that low δO-18 values are related to crustal processes. By filtering out data influenced by crustal assimilation, it is concluded that the low δO-18 values are derived from the Iceland mantle. Additionally, the study finds that the low δO-18 and low He-3/He-4 components have become increasingly apparent in the modern Iceland mantle, possibly due to enhanced mantle melting.
EARTH AND PLANETARY SCIENCE LETTERS
(2022)
Article
Geochemistry & Geophysics
Sunna Haroardottir, Simon Matthews, Saemundur A. Halldorsson, Matthew G. Jackson
Summary: In this study, a comprehensive geochemical database of Icelandic volcanic rocks was compiled to examine the spatial distribution and generation of geochemical heterogeneity in Iceland. The results show that mantle potential temperatures have a minor role, while lithospheric thickness plays a key role in generating geochemical heterogeneity.
Article
Green & Sustainable Science & Technology
Mar Alonso, Nemesio M. Perez, Pedro A. Hernandez, Eleazar Padron, Gladys Melian, Fatima Rodriguez, German Padilla, Jose Barrancos, Maria Asensio-Ramos, Thrainn Fridriksson, Hirochika Sumino
Summary: This study presents an extensive analysis of helium emissions and thermal energy released from volcanic systems, revealing a direct relationship between diffuse helium emissions and the rise of mantle fluids. These findings are important for inferring the existence of deep and hidden geothermal resources, especially in areas without obvious geothermal manifestations.
Article
Environmental Sciences
Jacob A. Cram, Clara A. Fuchsman, Megan E. Duffy, Jessica L. Pretty, Rachel M. Lekanoff, Jacquelyn A. Neibauer, Shirley W. Leung, Klaus B. Huebert, Thomas S. Weber, Daniele Bianchi, Natalya Evans, Allan H. Devol, Richard G. Keil, Andrew M. P. McDonnell
Summary: Particle flux attenuation is lower in anoxic environments compared to oxic environments. Microbial metabolism and zooplankton aggregation and disaggregation play important roles in shaping the particle flux. Observing and modeling particle spectra provide insights into these processes. The study found that particle flux attenuated very little throughout the anoxic water column. Large particles mainly disaggregated into smaller particles between the base of the photic zone and 500m. Many organisms migrated to regions with high particle disaggregation during the day.
GLOBAL BIOGEOCHEMICAL CYCLES
(2022)
Article
Meteorology & Atmospheric Sciences
Prabir K. Patra, Edward J. Dlugokencky, James W. Elkins, Geoff S. Dutton, Yasunori Tohjima, Motoki Sasakawa, Akihiko Ito, Ray F. Weiss, Manfredi Manizza, Paul B. Krummel, Ronald G. Prinn, Simon O'doherty, Daniele Bianchi, Cynthia Nevison, Efisio Solazzo, Haeyoung Lee, Sangwon Joo, Eric A. Kort, Suman Maity, Masayuki Takigawa
Summary: This study simulates atmospheric N2O using an atmospheric chemistry-transport model and compares the results with in situ measurements. It estimates N2O emissions from different sources and analyzes regional and global variations and their correlation with El Niño Southern Oscillation (ENSO).
JOURNAL OF THE METEOROLOGICAL SOCIETY OF JAPAN
(2022)
Article
Green & Sustainable Science & Technology
Peter Schlosser, Hajo Eicken, Vera Metcalf, Stephanie Pfirman, Maribeth S. Murray, Clea Edwards
Summary: This article discusses the actions taken to mitigate warming and adapt to change in the Arctic since the Paris agreement. It highlights the urgency and importance of action for the future, including collaborative research, supporting Indigenous rights and stakeholders' discourse, monitoring change, and deep decarbonization.
Article
Oceanography
Minming Cui, Anand Gnanadesikan
Summary: Copper distribution in the ocean differs from other nutrients like phosphate and silicate. Our study suggests that diatoms in the Southern Ocean play a particularly important role in marine copper distributions. The uptake of copper in the Southern Ocean is substantially higher than in other oceanic regions.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2022)
Article
Multidisciplinary Sciences
Daniele Bianchi, David A. Carozza, Eric D. Galbraith, Jerome Guiet, Timothy DeVries
Summary: Using a data-constrained marine ecosystem model, the study estimated the historical reduction of fish biomass due to fishing and the associated change in biogeochemical cycling rates. The research found that the impact of fishing on global fish biomass and biogeochemical cycling rates is comparable to that of anthropogenic climate change.
Article
Ecology
Jordyn E. Moscoso, Daniele Bianchi, Andrew L. Stewart
Summary: The relationship between size and other traits in planktonic food webs has long been a topic of study. Size structured ecosystem models (SSEMs) are often used to represent these ecosystems, but their coarsely discretized nature has limited their ability to resolve the phenomenon of quantization. This study investigates the conditions under which quantization occurs and the parameters that control the locations of biomass peaks along the size spectrum. It suggests an approach to discretizing SSEMs that leverages quantization to select a reduced number of size classes. The study shows that the location of biomass peaks is strongly influenced by predator-prey interactions, while variations in nutrient supply and ecosystem forcing have less impact. These findings provide insights for the discretization approach of size structured ecosystem models in Earth system models.
ECOLOGICAL MODELLING
(2022)
Article
Microbiology
Keith Arora-Williams, Christopher Holder, Maeve Secor, Hugh Ellis, Meng Xia, Anand Gnanadesikan, Sarah P. Preheim
Summary: The number, size and severity of aquatic low-oxygen dead zones are increasing worldwide. Microbial processes in low-oxygen environments have important ecosystem-level consequences. This study analyzed the microbial populations in the low-oxygen bottom waters of the Chesapeake Bay and found that sulfur-oxidizing microorganisms can serve as indicators of hypoxic conditions. Additionally, the study revealed connections between the sulfur, nitrogen, and oxygen cycles.
ENVIRONMENTAL MICROBIOLOGY
(2022)
Article
Environmental Sciences
D. J. Clements, S. Yang, T. Weber, A. M. P. McDonnell, R. Kiko, L. Stemmann, D. Bianchi
Summary: The abundance and size distribution of marine particles play a crucial role in various biogeochemical and ecological processes in the ocean, including carbon sequestration. The use of machine learning algorithms and UVP5 optical measurements allows for a global analysis and reconstruction of particle size distributions, revealing consistent global patterns. This approach provides a baseline for a better understanding of particle cycles in the ocean and opens up possibilities for global, three-dimensional reconstructions of PSD and sinking particle fluxes.
GLOBAL BIOGEOCHEMICAL CYCLES
(2022)
Article
Environmental Sciences
Ryohei Yamaguchi, Keith B. Rodgers, Axel Timmermann, Karl Stein, Sarah Schlunegger, Daniele Bianchi, John P. Dunne, Richard D. Slater
Summary: The authors use climate change projections to show that there will be earlier phytoplankton bloom initiation in most oceans, but the timing of the bloom peak will vary widely by region. The changes in both initiation and peak timing are driven by a decoupling between phytoplankton growth and zooplankton predation, with increased zooplankton predation playing a significant role in altering bloom peak timing globally. Only in limited regions is light limitation a primary factor affecting bloom initiation changes.
NATURE CLIMATE CHANGE
(2022)
Article
Marine & Freshwater Biology
Allison R. Moreno, Clarissa Anderson, Raphael M. Kudela, Martha Sutula, Christopher Edwards, Daniele Bianchi
Summary: Pseudo-nitzschia species are a major cause of harmful algal blooms along the western coast of the United States, and they can produce the neurotoxin domoic acid. The production of domoic acid is influenced by environmental factors such as nutrient limitation and light.
Article
Environmental Sciences
Pierre Damien, Daniele Bianchi, James C. McWilliams, Faycal Kessouri, Curtis Deutsch, Ru Chen, Lionel Renault
Summary: This study examines the biogeochemical cycles along the U.S. West Coast and finds that the rates and fluxes in the coastal areas are about twice as large as offshore. The interactions with sediment exchanges, submesoscale shelf currents, bottom boundary layer transport, and intensified cross-shelf export of shelf-produced materials further impact the coastal and open-ocean balances.
GLOBAL BIOGEOCHEMICAL CYCLES
(2023)
Article
Oceanography
Faycal Kessouri, Lionel Renault, James C. McWilliams, Pierre Damien, Daniele Bianchi
Summary: The Santa Barbara Channel is highly productive due to the interaction between submesoscale eddies generated by islands and fine-scale winds. These eddies enhance the injection of nutrients to the surface, leading to intense phytoplankton blooms. Additionally, the fine-scale winds drive the movement of low oxygen, acidic deep waters, which can have ecological consequences.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2022)
Article
Multidisciplinary Sciences
Rui Jin, Marie-Aude Pradal, Kalev Hantsoo, Anand Gnanadesikan, Pierre St-Laurent, Christian J. Bjerrum
Summary: A new biogeochemical model for Chesapeake Bay has been developed by combining two published models, resulting in improved simulation of nitrogen species and the inclusion of sulfur cycling. The comparison between the two original models helps to identify the key differences and make necessary choices for the new model's configuration.
Article
Environmental Sciences
Christopher Holder, Anand Gnanadesikan
Summary: Understanding the factors influencing phytoplankton abundance is crucial for marine ecology and its response to climate change. We analyzed the output of 13 Earth System Models (ESMs) and observational data to determine the role of environmental variables in phytoplankton biomass. The results showed that environmental parameters such as nutrients, light, and temperature play a significant role, with shortwave radiation and dissolved iron being the dominant predictors. However, the models predict unrealistically low levels of iron and high levels of light for maximum biomass.
GLOBAL BIOGEOCHEMICAL CYCLES
(2023)
Article
Geosciences, Multidisciplinary
Christopher Holder, Anand Gnanadesikan, Marie Aude-Pradal
Summary: Earth system models (ESMs) are useful tools for predicting and understanding the climate system. However, the estimates of the parameters used in ESMs can vary widely, and even small changes in these parameters can lead to unexpected results. The standard method for estimating ESM sensitivity has limitations, as the output of ESMs may match observational patterns due to compensating errors. Recent research has shown that neural network ensembles (NNEs) can extract the relationships between variables in ocean biogeochemical models, providing a more mechanistic examination of ESM outputs.
GEOSCIENTIFIC MODEL DEVELOPMENT
(2022)
Article
Geochemistry & Geophysics
Lingyu Zhang, Kristoffer Szilas
Summary: This study presents new petrological and geochemical data for the Narssaq Ultramafic Body (NUB) in the Itsaq Gneiss Complex of SW Greenland. The results indicate that the ultramafic rocks of NUB are not mantle residues, but instead represent crustal cumulates derived from high-Mg magmas.
EARTH AND PLANETARY SCIENCE LETTERS
(2024)
Article
Geochemistry & Geophysics
Rong Xu, Sarah Lambart, Oliver Nebel, Ming Li, Zhongjie Bai, Junbo Zhang, Ganglan Zhang, Jianfeng Gao, Hong Zhong, Yongsheng Liu
Summary: This study investigated the iron isotope compositions of Cenozoic basalts in Southeast China, finding significant variations related to different types of basalts and their respective sources.
EARTH AND PLANETARY SCIENCE LETTERS
(2024)
Article
Geochemistry & Geophysics
C. J. Ebinger, Miriam C. Reiss, Ian Bastow, Mary M. Karanja
Summary: The East African rift system is formed above mantle upwellings and the formation of rifts is related to lithospheric thinning and magmatic activity. The amount of splitting varies spatially and the fast axes are predominantly parallel to the orientation of the rifts. Thick lithospheric modules have less splitting and different orientations, which may indicate mantle plume flow. Splitting rotates and increases in strength as it enters the rift zones, suggesting that the anisotropy is mainly present at shallow depths.
EARTH AND PLANETARY SCIENCE LETTERS
(2024)
Correction
Geochemistry & Geophysics
Ekaterina Rojas-Kolomiets, Owen Jensen, Michael Bizimis, Gene Yogodzinski, Lukas Ackerman
EARTH AND PLANETARY SCIENCE LETTERS
(2024)
Article
Geochemistry & Geophysics
Robert W. Nicklas, Igor S. Puchtel, Ethan F. Baxter
Summary: Oxygen fugacity is a fundamental parameter for understanding redox processes in igneous systems. This study compares the Fe-XANES oxybarometry method with the V-in-olivine method for evaluating fO(2) in MORB lavas. The results show that the V-in-olivine method is not applicable to samples with low MgO content, and that the majority of Archean komatiite sources have lower fO(2) than modern MORB.
EARTH AND PLANETARY SCIENCE LETTERS
(2024)
Article
Geochemistry & Geophysics
Chunfei Chen, Stephen F. Foley, Sebastian Tappe, Huange Ren, Lanping Feng, Yongsheng Liu
Summary: The volatile components CO2 and H2O play a major role in mantle melting and heterogeneity. In this study, Ca isotopes were used to trace the lithological heterogeneity in alkaline magmatic rocks. The results revealed the presence of K-richterite and carbonate components as the source of alkaline magmas with low delta 44/40Ca values. These findings highlight the importance of Ca isotopes as a robust tracer of lithological variation caused by volatiles in the Earth's upper mantle.
EARTH AND PLANETARY SCIENCE LETTERS
(2024)
Article
Geochemistry & Geophysics
Timothee Jautzy, Gilles Rixhon, Regis Braucher, Romain Delunel, Pierre G. Valla, Laurent Schmitt, Aster Team
Summary: Although the current approach to estimate catchment-wide denudation rates using only 10Be concentrations has made significant progress in geomorphology, this study argues for the inclusion of 26Al measurements and testing of steady-state assumptions in slow eroding, formerly glaciated landscapes. The study conducted measurements of both 10Be and 26Al in stream sediments from the Vosges Massif in France and found that elevation, slope, channel steepness, and precipitation were the primary factors controlling denudation rates. The study also revealed a significant relationship between the extent of past glaciation and the cosmogenic (un-)steadiness in the stream sediments.
EARTH AND PLANETARY SCIENCE LETTERS
(2024)
Article
Geochemistry & Geophysics
Erik van der Wiel, Douwe J. J. van Hinsbergen, Cedric Thieulot, Wim Spakman
Summary: Numerical models of Earth's mantle dynamics can predict the vigour and mixing of mantle flow, and the average slab sinking rates are an unexplored parameter that can provide intrinsic information on these characteristics. Through numerical experiments, it has been found that slab sinking rates are strongly correlated with mantle convection and mixing, and may explain geochemical observations from hotspot volcanoes.
EARTH AND PLANETARY SCIENCE LETTERS
(2024)
