Summary

Characterisation of the Celtic Sea shelf using digital sea floor geomorphological and geophysical mapping approaches

The Celtic Sea is a key area for future development of renewable energy and aggregate resource by the Irish and UK governments. Its seabed geomorphology and near surface geology are critical to engineering and extraction plans, as well as informing on ecological habitat mitigation. Surprisingly, its seabed geology lacks detailed and comprehensive characterisation using modern methods, which forms the focus of this collaborative Ireland-UK PhD. The Celtic Sea floor has specific challenges due to its origins from shaping by past glacial-fluvial processes. Sea-level lowering and ice (re)advances resulted in multiple subaerial exposures of the sea floor and the development of a river/tunnel valley network, linked to the higher landmasses of SE Ireland and SW England and the NE-SW fluctuating main glacier ice fronts. The research will accordingly develop and apply high resolution digital sea floor geomorphological and sub-surface mapping approaches. Mapping outputs will be integrated with existing geophysical and geotechnical engineering datasets to construct 3D sea floor ground models for use by engineers, habitat ecologists and other net zero and blue economy stakeholders.

Image courtesy of the Netherlands Foreign Investment Agency

Aims

1. Reconstructing the geomorphological and sedimentological relicts of the fluvial and glacial activities in the Celtic Sea.
2. Understanding the potential of the fluvial/tunnel valley sediment as a seafloor hazard, with significant erosion and burial potential due to storm and tidal current remobilisation, impacting upon the stability of cables and structure anchoring / tethering onto and into the sea floor.
3. Understanding the potential of the fluvial/tunnel valley sediment as an exploitable resource (aggregate).