A5004041242- Methane Hydrates and Related Phenomena
- Marine and coastal ecosystems
- Geology and Paleoclimatology Research
- Geochemistry and Elemental Analysis
- Paleontology and Stratigraphy of Fossils
- Groundwater and Isotope Geochemistry
- Hydrocarbon exploration and reservoir analysis
- Atmospheric and Environmental Gas Dynamics
- Marine and environmental studies
- Marine Biology and Ecology Research
- Isotope Analysis in Ecology
- Soil and Water Nutrient Dynamics
- Aquatic Ecosystems and Phytoplankton Dynamics
- Microbial Community Ecology and Physiology
- Heavy metals in environment
- Phosphorus and nutrient management
- Mine drainage and remediation techniques
- Seismic Imaging and Inversion Techniques
- Ocean Acidification Effects and Responses
- Coastal wetland ecosystem dynamics
- Wastewater Treatment and Nitrogen Removal
- Geological and Geophysical Studies
- Geological formations and processes
- Geochemistry and Geologic Mapping
- Radioactive element chemistry and processing
Utrecht University
2015-2024
Radboud University Nijmegen
2022-2024
Radboud Institute for Molecular Life Sciences
2022-2024
Radboud University Medical Center
2022-2024
Royal Netherlands Institute for Sea Research
1993-2022
Netherlands Earth System Science Centre
2019-2021
Southern California University for Professional Studies
2018
University of Southern California
2018
Mitchell Institute
2018
Texas A&M University
2018
Abstract Methane (CH 4 ) is produced in many natural systems that are vulnerable to change under a warming climate, yet current CH budgets, as well future shifts emissions, have high uncertainties. Climate has the potential increase emissions from critical such wetlands, marine and freshwater systems, permafrost, methane hydrates, through temperature, hydrology, vegetation, landscape disturbance, sea level rise. Increased these would turn induce further climate change, resulting positive...
ABSTR ACT
The exchange of CO 2 between the atmosphere and global coastal ocean was evaluated from a compilation air‐water fluxes scaled using spatially‐explicit typology inner estuaries (excluding outer such as large river deltas) continental shelves. computed emission to (+0.27 ± 0.23 PgC yr −1 ) is ∼26% ∼55% lower than previous estimates while sink atmospheric over shelf seas (−0.21 0.36 at low end range (−0.22 −1.00 ). air‐sea flux per surface area (−0.7 1.2 molC m −2 double value in open based on...
Silicon (Si), in the form of dissolved silicate (DSi), is a key nutrient marine and continental ecosystems. DSi taken up by organisms to produce structural elements (e.g., shells phytoliths) composed amorphous biogenic silica (bSiO 2 ). A global mass balance model biologically active part modern Si cycle derived on basis systematic review existing data regarding terrestrial oceanic production fluxes, reservoir sizes, residence times for bSiO . The demonstrates high sensitivity biogeochemical...
Methane is a powerful greenhouse gas and its biological conversion in marine sediments, largely controlled by anaerobic oxidation of methane (AOM), crucial part the global carbon cycle. However, little known about role iron oxides as an oxidant for AOM. Here we provide first field evidence iron-dependent AOM brackish coastal surface sediments show that produced Bothnian Sea oxidized distinct zones iron- sulfate-dependent At our study site, anthropogenic eutrophication over recent decades has...
We present a spatially explicit global overview of nearshore coastal types, based on hydrological, lithological and morphological criteria. A total four main operational types act as active filters both dissolved suspended material entering the ocean from land: small deltas (type I), tidal systems (II), lagoons (III) fjords (IV). Large rivers (V) largely bypass filter, while karstic (VI) arheic coasts (VII) inactive filters. This typology provides new insight into spatial distribution...
Abstract. In river basins, soils, groundwater, riparian zones and floodplains, streams, rivers, lakes reservoirs act as successive filters in which the hydrology, ecology biogeochemical processing are strongly coupled together to retain a significant fraction of nutrients transported. This paper compares existing concepts with current approaches describe biogeochemistry, assesses value these for understanding impacts interacting global change disturbances on biogeochemistry. Through merging...
Soil nitrogen (N) budgets are used in a global, distributed flow-path model with 0.5° × resolution, representing denitrification and N 2 O emissions from soils, groundwater riparian zones for the period 1900–2000 scenarios 2000–2050 based on Millennium Ecosystem Assessment. Total agricultural natural inputs fertilizers, animal manure, biological fixation atmospheric deposition increased 155 to 345 Tg yr −1 (Tg = teragram; 1 10 12 g) between 1900 2000. Depending scenario, estimated further...
Abstract. Past characterizations of the land–ocean continuum were constructed either from a continental perspective through an analysis watershed river basin properties (COSCATs: COastal Segmentation and related CATchments) or oceanic perspective, regionalization proximal distal margins (LMEs: large marine ecosystems). Here, we present global-scale coastal segmentation, composed three consistent levels, that includes whole aquatic with its riverine, estuarine shelf sea components. Our work...
Hypoxia has occurred intermittently over the Holocene in Baltic Sea, but recent expansion from less than 10 000 km(2) before 1950 to >60 since 2000 is mainly caused by enhanced nutrient inputs land and atmosphere. With worsening hypoxia, role of sediments changes nitrogen removal release as ammonium. At present, denitrification water column equally important. Phosphorus currently buried organic form, with an additional contribution reduced Fe-phosphate minerals deep anoxic basins. Upon...
Studies of authigenic phosphorus (P) minerals in marine sediments typically focus on carbonate fluorapatite, which is considered to be the major sink for P and can easily semi-quantitatively extracted with SEDEX sequential extraction method. The role other potentially important phases, such as reduced iron (Fe) phosphate mineral vivianite (Fe(II)3(PO4)*8H2O) has so far largely been ignored systems. This is, part, likely due fact that method does not distinguish between associated Fe-oxides....
Volcanism is a dominant natural source of mercury (Hg) to the atmosphere, biosphere, ocean and sediments. In recent years, sedimentary Hg contents have emerged as tool reconstruct volcanic activity, particularly activity (subaerially emplaced) large igneous provinces in geological deep time. More specifically, has shown potential useful proxy illuminate previously elusive impact such large-scale volcanism on marine terrestrial paleo-environments. While now widely applied tracer, non-volcanic...
Research Article| November 01, 2003 Nanogoethite is the dominant reactive oxyhydroxide phase in lake and marine sediments Claar van der Zee; Zee 1Department of Physics, University Ottawa, Ontario K1N 5N6, Canada Search for other works by this author on: GSW Google Scholar Darryl R. Roberts; Roberts Denis G. Rancourt; Rancourt Caroline P. Slomp 2Department Geochemistry, Faculty Earth Sciences, Utrecht University, Budapestlaan 4, 3584 CD Utrecht, Netherlands Author Article Information...
A combination of pore water and solid phase analysis was used to determine whether authigenic carbonate fluorapatite (CFA) is currently forming in the sediment at two locations (OMEX I II) on North Atlantic continental platform Goban Spur (southwest Ireland). Results selective P extractions suggest that an early diagenetic redistribution Fe-bound may be occurring both stations. steady-state model describing depth profiles HPO 4 2- three forms (organic P, P) developed applied data station...
Abstract Invasive species and bottom‐water hypoxia both constitute major global threats to the diversity integrity of marine ecosystems. These stressors may interact with unexpected consequences, as invasive that require an initial environmental disturbance become established can subsequently important drivers ecological change. There is recent evidence improved oxygen conditions in coastal areas northern Baltic Sea coincide increased abundances polychaetes M arenzelleria spp. Using a...
Seasonal oxygen depletion (hypoxia) in coastal bottom waters can lead to the release and persistence of free sulfide (euxinia), which is highly detrimental marine life. Although hypoxia relatively common, reports euxinia are less frequent, suggests that certain environmental controls delay onset euxinia. However, these their prevalence poorly understood. Here we present field observations from a seasonally hypoxic basin (Grevelingen, The Netherlands), suggest activity cable bacteria,...
The present study examines oxygen and phosphorus dynamics at a seasonally hypoxic site in the Arkona basin of Baltic Sea. A coupled benthic–pelagic reactive‐transport model is used to describe evolution bottom‐water solute concentrations, as well pore‐water sediment profiles. Aerobic respiration dominates remineralization, with iron reduction, denitrification, sulphate reduction playing secondary roles, while other pathways are negligible. Sediments represent significant sink chiefly due...
Studies of phosphorus (P) dynamics in surface sediments lakes and coastal seas typically emphasize the role coupled iron (Fe), sulfur (S) P cycling for sediment burial release. Here, we show that anaerobic oxidation methane (AOM) also may impact such systems. Using porewater profiles sites an oligotrophic basin (Bothnian Sea), provide evidence formation Fe-bound (possibly vivianite; Fe3(PO4)2.8H2O) below zone AOM with sulfate. dissolved Fe2+ released from oxides is no longer scavenged by...
Abstract. The Paleocene–Eocene Thermal Maximum (PETM, ~ 56 Ma) was a 200 kyr episode of global warming, associated with massive injections 13C-depleted carbon into the ocean–atmosphere system. Although climate change during PETM is relatively well constrained, effects on marine oxygen concentrations and nutrient cycling remain largely unclear. We identify in sediment core from US margin Gulf Mexico. Biomarker-based paleotemperature proxies (methylation branched tetraether–cyclization...