The past as the key to the future: assessing ecological and landscape response to rising sea level

Sea-level rise is one of the greatest threats to the global community, but constraining large-scale landscape response is restricted to short-duration observational data.  By comparison, the palaeo record provides the opportunity to understand long-term responses of terrestrial and coastal areas to periods of past sea-level rise. Beneath the modern seabed of the southern North Sea is a terrestrial archive containing a wealth of information about environmental responses to changing climate and rising sea level.  The UK Climate Change Committee stated in 2018 that “climate change will exacerbate the already significant exposure of the English coast to flooding and erosion. The current approach to coastal management in England is unsustainable in the face of climate change.”  This project will provide a large-scale palaeo dataset which may be used to better forecast future coastline response to changing sea level.

During the last ice age, the southern North Sea comprised a terrestrial environment beyond the limit of the ice sheets, which extended across much of Europe.  As the ice sheets melted, sea level rose, submerging this palaeolandscape to become the modern North Sea.  Collecting core material from these environments is challenging and prohibitively expensive; but site investigations for new windfarms in the southern North Sea are providing a wealth of data, which makes this an exciting time to do this research.  Using this new offshore core material which the supervisory team have unique access too, this studentship will use Quaternary environmental reconstruction techniques (e.g. microfossil analysis such as pollen and diatoms, and sediment dating) to build an integrated model of palaeolandscape and ecological evolution of the southern North Sea, prior to its marine inundation in the early Holocene, from which to assess the ecological and landscape responses to rising sea level.

An example of the sediments preserved in the North Sea, collected in cores, which provide evidence of sea level rise during the Holocene.  Photo: Wessex Archaeology

In this project you will work with leading scientists in the School of Earth and Environment at the University of Leeds and CASE Partner Wessex Archaeology (the UK-leading consultancy in archaeological and heritage services) who have a wealth of expertise working in Quaternary sediments in the North Sea region, and beyond.  Specific objectives include, but are not limited to:

  • Reconstructing the palaeoenvironments of the southern North Sea using cores from offshore of Norfolk and the Thames.
  • Dating the timing of key palaeoenvironmental change within the sequences using radiocarbon analysis.
  • Assessing the ecological and landscape response to rising sea level using pollen and diatoms.
  • Developing models of landscape evolution.

Potential for high-impact outcomes
The results of this work will have multiple scientific outcomes, with interdisciplinary reach for the geoscience, archaeological, geoenergy and hazard-and-risk research communities.  Potential high-impact outcomes of the work include:

  • Improved understanding of large-scale landscape response following deglaciation and under rising sea level, to support forecasts of coastline responses and engineering strategies,
  • Provide palaeotopographic surfaces against which to calibrate palaeo-climate and glacial isostatic adjustment models,
  • Provide reconstructions of palaeolandscapes, which are critical for archaeological research,
  • Improved charaterisation of the shallow sub-surface which is important for offshore geo-energy projects and delivery of a low carbon future.

There is an increasing amount of offshore material becoming available for analysis; as result this PhD could provide the springboard for many further opportunities working in this area.  This project aligns to many NERC research priorities including climate and climate change (e.g. palaeoenvironments), archaeology, geosciences (e.g. Quaternary science), terrestrial and freshwater environments (e.g. Earth system processes and ecosystem-scale processes).

Training, CASE partner and wider research group
This research project will build upon collaboration between the University of Leeds, the offshore energy industry and Wessex Archaeology, as well as existing research relationships with the Dutch Geological Survey (TNO), Utrecht University and Deltares.  The successful candidate will have access to our expanding palaeoenvironmental laboratory within The School of Earth and Environment at Leeds and work along PhD students in similar areas, as well as in the Leeds Quaternary Group.  The lead supervisor (Dr Natasha Barlow) is currently leader of a large European Research Council project (RISeR) which focuses on the Last Interglacial environments in the southern North Sea which is complementary to this PhD, and is leader of the international PALeo constraints on SEA level rise (PALSEA) research group, therefore providing the potential for wider networking opportunities.

The project is supported by CASE Project Partner Wessex Archaeology who will provide an additional £3.5k over the 3.5 years of the studentship to enhance the students training grant (RTSG).  There will be opportunities for one or more research placements (a minimum of 3-months) at Wessex, whose head office is in Salisbury.  This will provide the student the opportunity for training (e.g. in pollen analysis and landscape modelling) as well as exposure to a archaeology and geoscience consultancy environment, during the course of the project.  The successful candidate will also have access to a broad spectrum of training workshops facilitated by the DTP at the University of Leeds.

Student profile
The ideal candidate will have a background in Quaternary environmental change, with a relevant degree e.g. Geography, Environmental Science or Geology.  A keen interest in environmental processes is desirable, in particular with a focus on the coastal landscape.  Some experience with microfossils (e.g. pollen, diatoms or testate amoeba) would be an advantage.

Example relevant papers by supervisory team
Barlow NLM, Long AJ, Gehrels WR, Saher MH, Scaife RG, Davies HJ, Penkman KEH, Bridgland DR, Sparkes A, Smart CW, Taylor S. 2017. Relative sea-level variability during the late Middle Pleistocene: new evidence from eastern England. Quaternary Science Reviews. 173, pp. 20-39
Emery AR, Hodgson DM, Barlow NLM, Carrivick JL, Cotterill CJ, Mellett CL, Booth AD. 2019. Topographic and hydrodynamic controls on barrier retreat and preservation: An example from Dogger Bank, North Sea. Marine Geology. 416 105981
Mellett CL, Hodgson DM, Plater AJ, Mauz B, Selby I, Lang A. 2013. Denudation of the continental shelf between Britain and France at the glacial-interglacial timescale. Geomorphology. 203, pp. 79-96