A5049878246- Groundwater and Isotope Geochemistry
- Geology and Paleoclimatology Research
- Methane Hydrates and Related Phenomena
- Geochemistry and Elemental Analysis
- Groundwater flow and contamination studies
- Marine and coastal ecosystems
- Silicon Effects in Agriculture
- Geological and Geophysical Studies
- Hydrocarbon exploration and reservoir analysis
- Coastal wetland ecosystem dynamics
- Microbial Community Ecology and Physiology
- Atmospheric and Environmental Gas Dynamics
- Diatoms and Algae Research
- Geophysical and Geoelectrical Methods
- Isotope Analysis in Ecology
- Marine and environmental studies
- Hydraulic Fracturing and Reservoir Analysis
- Geochemistry and Geologic Mapping
- Seismic Imaging and Inversion Techniques
- Geological Studies and Exploration
- Geomagnetism and Paleomagnetism Studies
- Karst Systems and Hydrogeology
- Coastal and Marine Dynamics
- Water Quality Monitoring and Analysis
- Geophysical Methods and Applications
Carl von Ossietzky Universität Oldenburg
2015-2025
Oldenburger Institut für Informatik
2023
Abstract Terrestrial groundwater travels through subterranean estuaries before reaching the sea. Groundwater‐derived nutrients drive coastal water quality, primary production, and eutrophication. We determined how dissolved inorganic nitrogen (DIN), phosphorus (DIP), organic (DON) are transformed within estimated submarine discharge (SGD) nutrient loads compiling > 10,000 samples from 216 sites worldwide. Nutrients exhibited complex, nonconservative behavior in estuaries. Fresh DIN DIP...
Submarine groundwater discharge (SGD) from intertidal beach systems forms a source of fresh and saline, often nutrient-enriched water to the near-shore across world. The chemical composition solute flux via SGD depends on several factors, including solid phase composition, organic matter supply, hydraulic gradients, as well pore residence time origin, which are partly related topography. High-energy sandy beaches especially prone frequent sediment relocation variable topography,...
Microbial communities in subsurface coastal sediments are highly diverse and play an important role nutrient cycling. While the major fraction of microorganisms sandy lives as epipsammon (attached to sand grains), only a small thrives interstitial porewaters. So far, little is known about composition these free-living microbial communities. In beach, investigated this study, we compared archaeal bacterial community structures within corresponding porewaters applying 16S rRNA gene sequencing....
Subterranean estuaries are connective zones between inland aquifers and the open sea where terrestrial freshwater circulating seawater mix undergo major biogeochemical changes. They reactors that modify groundwater chemistry prior to discharge into sea. We propose subterranean of high-energy beaches particularly dynamic environments, effect boundary conditions propagates tens meters subsurface, leading strong spatio-temporal variability geochemical conditions. hypothesize they form a unique...
The use of rare earth elements (REEs) as tracers for oceanic processes requires knowledge and quantification their sources sinks. Submarine groundwater discharge (SGD) has been suggested to be a potentially important source REEs other trace the ocean. To investigate affecting in subterranean estuary (STE) sandy beach system contribution coastal waters southern North Sea, we analyzed dissolved REE concentrations pore waters, seawater fresh on barrier island Spiekeroog, German Sea. show...
The impact of freshwater sources like surface river runoff and submarine groundwater discharge (SGD) on coastal waters is currently in focus intense debate investigation. One the ongoing challenges SGD research characterization quantification endmember contributions to subsurface mixing zone their influences element balance biogeochemical transformations. Long-term investigations sediment porewater composition provide understanding physical, hydrological processes controlling substance...
Freshwater lenses connect the terrestrial and marine realm via groundwater discharge at edges of islands serve as drinking water resources. We studied redox-sensitive metals U, Mo, V, Tl along redox gradient fresh on Spiekeroog Island, northern Germany. Groundwater solute concentrations were linked to age characteristics. further quantified contribution precipitation, sea spray, aquifer matrix metal evaluated sink source function under oxic reducing conditions. found that biogeochemical...
Subterranean estuaries below high-energy beaches are understudied, despite being potential powerful biogeochemical reactors at the land/sea transition zone affecting quality of coastal waters. Highly transient hydro(geo)logical boundary conditions and density-effects lead to dynamic subsurface flow transport patterns which difficult understand hard replicate by models. A comprehensive unique 1-year dataset hydraulic heads, salinity temperature data in combination with apparent 3H/He ages was...
In beach aquifers two water bodies, relatively old terrestrial freshwater and young oceanic saltwater mix, biogeochemical reactions change the solute composition of groundwater discharge modifies element net fluxes to ocean. Residence times are baseline information for interpretation help understand flow transport regimes. present study we used environmental tracers, i.e. apparent tritium-helium (3H/He) ages, temperatures silica (Si) concentrations derive ages travel in subsurface along a...
Coastal aquifers, the transition zone between freshwater and saltwater, show large salinity contrasts in subsurface. Salinity is a key parameter to understand coastal groundwater flow dynamics consequently also geochemical microbial processes. For mapping porewater salinity, variety of methods exists, mainly using electrical conductivity as proxy. We investigate including hydrological/geochemical (well sampling, fluid logger) well geophysical method (direct push, geoelectrics) utilising...
Intertidal permeable high energy beach systems represent complex biogeochemical reactors which attract increasing scientific attention. In these environments morphology variations lead to and dynamic groundwater flow paths, saltwater-freshwater mixing zones, changing conditions. The aim of our study was assess the spatio-temporal dynamics in hydrobiogeochemistry continuum between a deep subterranean estuary (STE) surface high-energy on Spiekeroog Island (Germany). Several permanent wells...
Subterranean estuaries (STE) of high energy beaches are important coastal reactors that can alter elemental fluxes to the sea. The advective flow pore water in these STE systems has rapid transport rates due permeability medium coarse grained sediments. This is controlled by inland hydraulic gradient, density differences caused different matrixes (fresh and saline), oceanic forces (tides waves). Rare earth elements (REEs) useful tracers for biogeochemical processes like scavenging, redox...
High-energy beaches mark a highly variable land-ocean transition where matter fluxes are modulated by dynamic subsurface biogeochemical reactions. At the beach face, seawater infiltration into saline recirculation cell of intertidal aquifer creates high input electron acceptors and organic matter. Microorganisms rapidly degrade fresh in upper sandy layer under advective flow conditions. Filtration particulate constant supply oxygen (O2) shallow sand body result much this turnover taking...
Coastal aquifers build the transition zone of freshwater and saltwater. Hence, large salinity gradients are encountered in subsurface below beaches it is important to assess a high resolution order understand coastal groundwater flow dynamics consequently geochemical microbial processes subterranean estuaries. Within project DynaDeep, we used both geophysical hydrogeological methods determine bulk fluid electrical conductivities (bulk/fluid EC) with aim convert EC monitor its temporal...