Constraining Holocene coastal response to marine transgression to predict future coastal realignment
Global sea-level change is one of the greatest environmental hazards facing society. The IPCC AR5 projects future rise in global mean sea level to be 0.62 ± 0.36 m above present by 2081–2100. Furthermore, the rate of sea-level rise is increasing and will impact coastal populations globally. Understanding the causes, rates, and consequences of marine transgression is critical to improved coastal zone mitigation strategies. Integrated datasets that record the process response to recent periods of sea-level rise need to be analysed in order to constrain and predict responses to future marine transgression along different coastline types. This is now possible due to a revolution in the amount of high quality offshore data, which is being driven by windfarm site investigation work. One of the most comprehensive integrated offshore datasets available is on the Dogger Bank, and will be used in this studentship. The custodians of this vast and growing database are the British Geological Survey (BGS).
The Dogger Bank dataset affords the opportunity to document sedimentary process response in littoral and paralic zones during a period of transgression over a 2000 km2 area. The dataset to be used includes seabed bathymetry and imagery, a grid of 2D seismic lines (~100 x 500 m spacing of both Sparker and Pinger), and >20 short vibrocores. Mapping of seismic facies and key surfaces, calibrated to sedimentary facies in vibrocores, will permit the 3D distribution of Holocene depositional environments and grain-sizes to be established. Seabed bathymetry and imagery will inform the role of recent processes in the Dogger Bank area. The presence of peats and evidence of human settlement in the Dogger Bank area provide an opportunity to date the deposits and constrain a chronology.
The rate of eustatic sea-level rise during the Holocene was non-linear, and globally is characterised by an initial period of rapid rise, followed by a period of slower rise. This general transgressive trend is thought to be punctuated by abrupt sea-level rise events that are linked to pulses to large volume discharge of melt-water. Locally, relative sea-level curves are further complicated by parameters such as isostatic rebound and tectonism, particularly in former ice marginal settings such as the North Sea.
The research outcomes from this studentship are to 1) constrain the stratigraphic and sedimentary evolution of the Dogger Bank area during the Holocene, 2) improve understanding of process response and realignment near to coastlines during periods of sea-level rise, 3) inform predictive numerical models of coastal realignment scenarios, and 4) inform local and governmental planning and mitigation strategies for the protection of coastal areas. The research also has the potential to impact business decisions of offshore windfarm companies through influencing engineering strategies and turbine locations.
The interdisciplinary nature of this studentship means that the student will be trained in process sedimentology and stratigraphy, seismic mapping techniques, and GIS. The student will fully participate in the School and University postgraduate training programme and will be encouraged to attend and present at national and international conferences, and will be strongly encouraged to write their thesis as a collection of manuscripts. There will also be an opportunity to spend time on placement at the British Geological Survey.
Entry requirements/necessary background for students:
MSc, geology or geophysics first degree, with experience of using seismic data
How good is research at University of Leeds in Earth Systems and Environmental Sciences?
FTE Category A staff submitted: 79.20
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