My research interests are interdisciplinary, at the interface of Quaternary science (palaeoclimatology and geochronology), hydrogeology and geomorphology. I am interested in understanding the nature and impacts of past environmental change and the mechanisms of global climate forcing, with a focus on deserts and drylands over timescales of glacial-interglacial cycles down to recent decades. My current projects fall within two main themes:
Chemical tracers as novel proxies for environmental change and records of groundwater recharge and quality
This research concerns developing the use of chemical tracers and isotopic signals proxies in dryland sediments and groundwater as novel proxies for past environmental conditions. The portion of sediment of particular interest is that part above the water table, known as the unsaturated zone (USZ) (or vadose zone), because it has the potential to store records of decadal-scale resolution. Reconstructing rainfall fluctuations and moisture availability in drylands is challenging, which makes the USZ and groundwater extremely valuable key archives. The main goals of this research are to: (i) characterise the chemical signature that establishes in the near-surface zone of the USZ and explore the transport of this signal down through the USZ, which yields a ‘hydrostratigaphy’, (ii) assess the extent to which hydrostratigraphies may be used as indicators of past environments, and (iii) apply the information that hydrostratigraphies contain about land-use change through the influence land-use change has over infiltration/recharge rates and the quality of the infiltrating water.
Quaternary dryland environmental dynamics
A related research interest is the reconstruction of past environmental and climate variability in dryland regions through a study of landscape dynamics through the Quaternary. The overarching aim is to elucidate the nature of the climate of the past in southern Africa in order to understand both what forced the climate and the complex nature of this response. By doing this, we provide a scientific basis to facilitate realistic projects of future climate change within this environmentally sensitive region of the world.
This research involves investigating the past environmental records contained within fluvial tufa, sand dunes and within former river channels. My main regional focus is southern Africa, with a particular emphasis on the Namib Sand Sea. I combine detailed studies at individual sites with systematic reviews and evaluations of the overall evidence base in the Namib Sand Sea and across southern Africa.
Geochronology is key to reconstructing these past changes, and my major research interest here is within luminescence dating. I am interested in investigating fundamental luminescence properties of sediments and developing the use of portable luminescence readers to aid with rapid age assessment out in the field.