Geology and Society Projects

Submerged landscapes: blue carbon sinks or sources?

The world’s oceans are a huge store of carbon; however much ‘blue carbon’ research focuses on carbon dissolved in the water column, or within shallow seabed sediments. Buried submarine peats are huge stores of organic carbon that are currently unaccounted for, and have the potential to be eroded or reworked due to changing hydrodynamics and use of the seabed for a range of activities.

Subsurface data collected as part of offshore windfarm development around the NW European continental shelf have revealed a highly-heterogeneous stratigraphic record of multiple phases of ice sheet advance and retreat. In the southern North Sea, these data have shown the preservation of extensive interglacial peat layers that record periods of relatively stable accumulation of terrestrial and coastal organic carbon.

What is missing is a spatial inventory of peats, identified in cores, geotechnical boreholes, and seismic reflection. Our close collaborations with Belgian, Dutch and UK research groups’ permits development of a database that crosses international boundaries. Samples will be analysed to quantify total organic carbon to establish a better understanding and accounting of carbon stocks held within these buried palaeoenvironments.

Academic lead – Dr Natasha Barlow

From geoscience to sustainable energy use: investigating geothermal potential in Yorkshire

Geothermal energy is an exciting and bountiful sub-surface source of clean energy, currently still largely untapped across the UK. The structure and geological story of sub-surface Yorkshire presents many geothermal opportunities: from deep thermal energy extraction from underlying granite systems through to heat storage in extensive networks of disused mine across the region. This, combined with the availability of an extensive array of surface and subsurface data from across the region, makes Yorkshire an exciting place to investigate the potential for future geothermal sites.

This project will look to assess the geothermal potential of a segment of the sub-surface located in the Ryedale region of the Askrigg Block (Waters et al, 2020). You will use an array of existing available data, including seismic and borehole geochemical and geophysical data, to develop a conceptual model of the subsurface geothermal system (Cumming, 2009). This will include modelling key controlling structures, assessing potential influence of local and regional stress systems and, with incorporation of all available geophysical data, an assessment of likely thermal conduction, potential heat flow paths and hydrothermal potential (Jolie et al,. 2015). Using the conceptual model, you will determine likely geothermal output potential of this system including temperature and flow rates. Finally, using this data you will develop a plan for potential routes of sustainable use of the energy resource within the region.

Your work will help establish an improved understanding of the geothermal potential in Yorkshire and be part of a wider project to map the region and develop a long term plan for harnessing geothermal energy as part of the UK’s energy transition to efficient, long-term and environmentally friendly energy.

Academic lead – Dr Emma Bramham

Characterization of sedimentary heterogeneity in giant saline aquifers to assess suitability for long-term underground CO2 storage

This project will determine the suitability of giant subsurface saline aquifers for the safe and long-term storage of CO2. Very large storage volumes within unclosed Triassic saline aquifers of the UK have the potential to contribute significantly to the solution of what is the most pressing problem faced by the world today: how to dramatically reduce emissions of greenhouse gas to the atmosphere. The successful candidate will use techniques in sedimentary facies analysis, structural geology, basin analysis, petrophysics and reservoir modelling to investigate the role of lithological heterogeneity in determining injectivity of CO2 into aquifers and the ability of low-permeability seal units to act as barriers to the upward movement of CO2. Although depleted UK oil and gas reservoirs are attractive short-term targets for CO2 storage because their geological character is known, their storage capacities are limited. Much larger saline aquifers must additionally be utilised if the majority of carbon produced by the UK’s large point source emitters (e.g., cities, power stations) is to be sequestered effectively over coming decades. Triassic saline aquifers of the UK Southern North Sea, East Irish Sea Basin and adjacent onshore areas, with their favourable porosity and permeability character and their stratigraphical juxtaposition to seals, can potentially store significantly more CO2 than the combined capacity of the regions’ depleted hydrocarbon fields. This project will undertake a combined outcrop and subsurface characterisation of the Triassic Bunter and Ormskirk Sandstone formations (and lateral equivalents), two of the largest UK saline aquifers considered as potentially suitable for long-term CO2 storage. The size, shape, frequency and degree of interconnectivity of sedimentary geobodies will be characterised. Results will quantify net CO2 storage potential, will predict injectivity within different sedimentary successions, will predict flow migration pathways, and will assess the ability of aquifers to retain CO2 over long time scales. Fluvial, Eolian & Shallow-Marine Research Group (http://frg.leeds.ac.uk/)

Academic lead – Professor Nigel Mountney