African Humid Period Palaeofloods on the Sahara Desert Margins

Supervisors

Dr Martin Stokes (School of Geography, Earth and Environmental Sciences, University of Plymouth)

Professor Anne Mather (School of Geography, Earth and Environmental Sciences, University of Plymouth)

Professor Fin Stuart (Scottish Universities Environmental Research Centre, University of Glasgow)

Dr Sarah Boulton (School of Geography, Earth and Environmental Sciences, University of Plymouth)

Supervisors

Dr Martin Stokes (School of Geography, Earth and Environmental Sciences, University of Plymouth)

Professor Anne Mather (School of Geography, Earth and Environmental Sciences, University of Plymouth)

Professor Fin Stuart (Scottish Universities Environmental Research Centre, University of Glasgow)

Dr Sarah Boulton (School of Geography, Earth and Environmental Sciences, University of Plymouth)

Project background

This project investigates the size, timing and impact of African Humid Period (AHP) palaeofloods on upland landscapes along the Sahara Desert margins. Wobbling of the Earth’s axial spin alters atmospheric circulation patterns every ~20,000yrs, repeatedly bringing wetter climates and flooding (~5,000yr duration) to continental Africa (‘Greening’ of the Sahara). Investigations will analyse mountain fronts from different latitudinal and continentality contexts using Quaternary-Recent alluvial fans (cone-shaped sediment bodies formed on valley sides and mountain fronts). These landforms possess flood-related sedimentary and geomorphological records with significant but unrealised large spatial and long temporal potential to inform on climate change sensitive drylands; areas of early human occupation (archaeology) and modern population pressures (flood hazard).

Research will investigate key sites along the western Saharan Desert margin (offshore islands (humid), coastal (arid) and inland (hyperarid): Cape Verde-Morocco: 14-28°N). AHP flood size quantification requires measurement of flood sediments (boulder size) and geomorphology (slope and flood inundation area). This involves fieldwork and satellite GIS analysis of palaeoflood and modern (for comparison / model calibration) flood sites using hydrological modelling approaches (e.g. flood regime). The timing of palaeoflood events uses cosmogenic exposure dating techniques (i.e. 3He, 10Be, 26Al) applied to boulder surfaces deposited from different palaeoflood events. The impact of localised alluvial fan AHP flooding will utilise inter-site comparisons and comparisons with hydrological change datasets from other AHP archives (rivers, lakes, marine cores).

Training

The PhD candidate will become a flood scientist with a field-laboratory-computing skillset of relevance to environmental government agencies or industry consultancy employment. Specialist training in remote sensing, fieldwork, geochronology, and hydrological modelling will utilise Plymouth/Glasgow expertise and laboratories (SUERC). Generic research training skills will be undertaken via the ARIES/Plymouth doctoral training colleges (project management, health and safety, data management, research communication / publishing). The candidate will become a member of international flood science networks (INQUA) for conference results communication and advanced training workshop opportunities.

Person specification

This PhD is suitable for candidates with degrees in geology / earth science / physical geography. Fieldwork and GIS experience is desirable. A willingness to travel and rise to the challenge of working in hot / remote desert locations is essential.

References

  • 1. deMenocal, P.B., Tierny, J.E., 2012. Green Sahara: African Humid Periods Paced by Earth's Orbital Changes. Nature Education Knowledge 3, 12.
  • 2. Larrasoaña, J.C., et al., 2013. Dynamics of green Sahara periods and their role in hominin evolution. PloS one, 8(10), p.e76514.
  • 3. Mather, A., Stokes, M., 2016. Extracting palaeoflood data from coarse‐grained Pleistocene river terrace archives: an example from SE Spain. Earth Surface Processes and Landforms, 41(13), pp.1991-2004.
  • 4. Stokes, M., Mather, A.E., 2015. Controls on modern tributary-junction alluvial fan occurrence and morphology: High Atlas Mountains, Morocco. Geomorphology, 248, pp.344-362.
  • 5. Stokes, M., Gomes, A., 2020. Alluvial fans on volcanic islands: A morphometric perspective (São Vicente, Cape Verde) Geomorphology, in press. https://doi.org/10.1016/j.geomorph.2020.107356.

Key information

  • This project has been shortlisted for funding by the ARIES NERC DTP and will start on 1 October 2021. The closing date for applications is 23:59 on 12 January 2021.
  • Successful candidates who meet UKRI’s eligibility criteria will be awarded a NERC studentship, which covers fees, stipend (£15,285 p.a. for 2020-21) and research funding. For the first time in 2021/22 international applicants (EU and non-EU) will be eligible for fully-funded UKRI studentships. Please note ARIES funding does not cover visa costs (including immigration health surcharge) or other additional costs associated with relocation to the UK.
  • ARIES students benefit from bespoke graduate training and ARIES provides £2,500 to every student for access to external training, travel and conferences. Excellent applicants from quantitative disciplines with limited experience in environmental sciences may be considered for an additional 3-month stipend to take advanced-level courses in the subject area.
  • ARIES is committed to equality, diversity, widening participation and inclusion in all areas of its operation. We encourage enquiries and applications from all sections of the community regardless of gender, ethnicity, disability, age, sexual orientation and transgender status. Academic qualifications are considered alongside significant relevant non-academic experience.
  • All ARIES studentships may be undertaken on a part-time or full-time basis, visa requirements notwithstanding
  • For further information, please contact the supervisor.