A5080415256- Groundwater and Isotope Geochemistry
- Methane Hydrates and Related Phenomena
- Geology and Paleoclimatology Research
- Groundwater flow and contamination studies
- Geological Studies and Exploration
- Marine and environmental studies
- Marine and coastal ecosystems
- Hydrocarbon exploration and reservoir analysis
- Karst Systems and Hydrogeology
- Geophysics and Gravity Measurements
- Aquatic and Environmental Studies
- Isotope Analysis in Ecology
- Geological and Geophysical Studies
- Coastal and Marine Dynamics
- Hydraulic Fracturing and Reservoir Analysis
- Coastal wetland ecosystem dynamics
- Sustainability and Climate Change Governance
- Wastewater Treatment and Nitrogen Removal
- Water Quality Monitoring Technologies
- Seismic Imaging and Inversion Techniques
- Geochemistry and Elemental Analysis
- Coastal and Marine Management
- Remote Sensing and Land Use
- Underwater Vehicles and Communication Systems
- Geophysical Methods and Applications
Carl von Ossietzky Universität Oldenburg
2017-2024
Redox conditions are a major control for the concentrations and mass fluxes of water constituents, e.g., nutrients, metals organic molecules within subterranean estuaries (STE). Due to transient flow transport processes in STEs as well variable temperatures input redox reactants, zoning STE is believed be highly dynamic. In present study we analyzed individual combined effects storm floods, seasonal changes groundwater recharge rates, beach morphodynamics on STE. For this purpose, 2D...
The drinking water supply on barrier islands largely depends freshwater lenses, which are also highly relevant for island ecosystems. lens presented in this study is currently developing (since the 1970s) below very young eastern part of North Sea Spiekeroog, so-called “Ostplate.” Due to absence coastal protection measures, formation, shape, and extent Ostplate unaffected by human activities but exposed dynamic changes, e.g., geomorphological variations storm tides. main aim paper was...
Abstract. In high-energy beach aquifers fresh groundwater mixes with recirculating saltwater and biogeochemical reactions modify the composition of discharging to sea. Changing morphology, hydrodynamic forces, hydrogeological properties control density-driven flow transport processes that affect distribution chemical reactants. present study, modelling a generic 2-D cross-shore transect was conducted. Boundary conditions aquifer parameters were varied in systematic manner suite 24 cases. The...
Abstract Groundwater abstraction and drainage are considered to be the main drivers for salinization of low‐lying coastal groundwater systems, while role past boundary conditions is less clear. In this study, 3‐D paleo‐hydrogeological variable‐density flow salt transport modeling (“paleo‐modeling”) applied reconstruct evolution salinities during Holocene, that is, last 9,000 years, in Northwestern Germany. Novel aspects study include consideration highly resolved time‐variant a...
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...
Advective flows of seawater and fresh groundwater through coastal aquifers form a unique ecohydrological interface, the subterranean estuary (STE). Here, freshly produced marine organic matter oxygen mix with groundwater, which is low in contains aged carbon (OC) from terrestrial sources. Along flow paths, dissolved (DOM) degraded inorganic electron acceptors are successively used up. Because different DOM sources ages, exact degradation pathways often difficult to disentangle, especially...
Subterranean estuaries (STE) are hotspots of biogeochemical reactions. Here, dissolved constituents in waters terrestrial and marine origin transformed before they discharge to the coastal oceans. The involved reactions complex non-linear, calling for application numerical reactive transport modeling (RTM) improve process understanding. aim this study was assess roles organic matter degradation coupled secondary mineral fate species STEs sandy beaches. A comprehensive RTM approach applied...
Abstract Fresh coastal groundwater is a valuable water resource of global significance, but its quality threatened by saltwater intrusion. Excessive abstraction, sea‐level rise (SLR), land subsidence and other climate‐related factors are expected to accelerate this process in the future. The objective study (a) quantify impact projected climate change (b) explore role individual hydrogeological boundaries on salinization low‐lying systems until 2100 CE. We employ numerical density‐dependent...
Groundwater salinization due to sea-level rise is a problem that governance actors in coastal areas of the North Sea region have overseen for long period. As an ecological associated with climate change, it can be severely exacerbated by careless water management. This paper studies processes, actor perspectives and responses groundwater East Frisian regions German coast. Due its low-lying landscape, large land remain below sea-level, making urgent concern. Our research questions are: (i)...
Abstract. In high-energy beach aquifers fresh groundwater mixes with recirculating saltwater and biogeochemical reactions modify the composition of discharging to sea. Changing morphology, hydrodynamic forces as well hydrogeological properties control density-driven flow transport processes that affect distribution chemical reactants. present study, modelling a generic 2-D cross-shore transect was conducted. Boundary conditions aquifer parameters were varied in systematic manner suite...
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...
Dissolved species of terrestrial and marine origins are transformed in Subterranean Estuaries (STEs) before they flow into the coastal oceans. The occurring biogeochemical reactions highly complex, demanding application numerical reactive transport modeling (RTM) approaches to achieve a deeper process understanding. objective this study was quantify impact organic matter degradation secondary mineral on fate dissolved generic sandy STE. A comprehensive RTM approach developed for purpose,...
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...
Subterranean estuaries (STE) below beaches are biogeochemical reactors that modify the composition of fresh meteoric groundwater and recirculating seawater before they enter ocean via submarine discharge (SGD), which can affect coastal ecosystems. Thereby, prevailing redox conditions have a major impact on concentrations mass fluxes water constituents, e.g., nutrients, metals organic molecules within STE. Due to transient nature flow transport STEs as well variable hydrogeochemical boundary...