The Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research (AWI) is a member of the Helmholtz Association (HGF) and funded by federal and state government. AWI focuses on polar and marine research in a variety of disciplines such as biology, oceanography, geology, geochemistry and geophysics thus allowing multidisciplinary approaches to scientific goals.

PhD position in Investigating Offshore Groundwater Hydrology and Submarine Groundwater Discharge (f/x/m/d)

Background
Within the international JPI Oceans project AQUA-SHELF – A Proof-of-Concept Scientific Drilling Campaign for Offshore Freshened Groundwater Systems, we seek a highly motivated PhD candidate to investigate offshore freshened groundwater (OFG), submarine groundwater discharge (SGD), and their connection to coastal groundwater systems.

OFG represents an important but still poorly understood component of coastal groundwater systems. Key questions concern its origin and age, hydraulic connectivity with terrestrial aquifers, and its potential expression as groundwater discharge at the seafloor. AQUA-SHELF combines the first dedicated European offshore drilling campaign targeting OFG with geochemical, hydrogeological and geophysical investigations.
Well-characterised SGD sites in the Baltic Sea will serve as natural laboratories for developing and testing monitoring approaches using hydroacoustic mapping, environmental sensors and targeted sediment and pore-water sampling. The monitoring and detection approaches developed in the Baltic Sea will subsequently be applied and adapted to the northern Adriatic Sea, where AQUA-SHELF will conduct the first dedicated European offshore drilling campaign to investigate offshore freshened groundwater.
These scientific boreholes will provide direct access to offshore aquifers and enable the collection of groundwater, pore-water and sediment samples from different depths. A central component of the PhD will be the geochemical and isotopic characterisation of these samples to constrain groundwater origin and age, freshwater–seawater mixing, recharge conditions and residence times. The overall aim is to better understand whether offshore groundwater in the northern Adriatic represents a largely isolated palaeo-groundwater resource or remains dynamically connected to modern coastal groundwater systems.

The position will be based at the AWI Wadden Sea Station on Sylt and embedded in an interdisciplinary research environment covering coastal geology, marine environmental research and coastal processes.

The PhD project will be closely linked to the international AQUA-SHELF consortium and will involve collaboration particularly with Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) for groundwater geochemistry and isotope hydrology and Christian-Albrechts-Universität zu Kiel (CAU) for marine geophysical investigations.

You will spend research periods at partner institutions and participate in joint marine field campaigns. The project therefore provides the opportunity to combine marine fieldwork, autonomous environmental monitoring, geochemistry and interdisciplinary data integration within one PhD project.

• Plan and participate in marine field campaigns in the Baltic Sea and the northern Adriatic Sea
• Detect and characterise submarine groundwater discharge using hydroacoustic, geochemical and environmental observations
• Deploy and analyse seabed monitoring systems measuring parameters such as electrical conductivity and temperature
• Collect and analyse sediment, pore-water and groundwater samples
• Investigate groundwater origin, age, freshwater–seawater mixing and potential recharge pathways using geochemical and isotopic data
• Integrate hydroacoustic, environmental, geochemical and hydrogeological datasets to assess land–sea groundwater connectivity
• Contribute to the scientific interpretation of samples and observations from the Adriatic offshore drilling campaign
• Publish results in peer-reviewed journals and present them at national and international conferences

• Master's degree or equivalent in geosciences, hydrogeology, marine geology, environmental sciences, geochemistry, geophysics or a closely related discipline
• Strong interest in interdisciplinary marine and groundwater research
• Knowledge of hydrogeology, submarine groundwater discharge, coastal groundwater systems or groundwater geochemistry
• Experience with fieldwork and/or geochemical or environmental datasets
• Experience with one or more relevant methods, such as hydroacoustics, marine geophysics, environmental sensors, sediment or pore-water sampling, isotope or hydrochemical analyses
• Experience with quantitative data analysis using R, Python, MATLAB or comparable software; GIS experience is advantageous
• Very good command of English (approximately equivalent to CEFR level C1); knowledge of German is advantageous but not required
• Willingness to participate in multi-day marine research cruises and international field campaigns

• Excellent research environment with access to globally unique infrastructure, comprehensive datasets, and international expeditions
• Opportunity to develop and pursue independent scientific ideas and innovative research approaches addressing societally relevant questions
• Close scientific collaboration and interdisciplinary cooperation within the institute as well as with national and international partners
• An international working environment with daily interaction with colleagues from around the world
• Opportunities for professional and personal development
• Flexible working hours and the possibility of mobile working for up to 50% of regular working hours
• Annual special payment in accordance with the German public sector collective agreement (TVöD Bund)
• Occupational health promotion and company fitness programme with Hansefit
• Support services and an established culture promoting work–life balance, e.g. through our family office offering childcare services (e.g. holiday programmes) as well as advice on family and care responsibilities
• Occupational pension scheme (VBL)