PhD topic ideas for physical geographers

We asked some of our physical geographers to suggest topics that they'd like to see explored by PhD candidates.

An eroded sand dune with a warning sign on it

Historical storminess in the North Sea

Knowing the long-term variability of storm tracks, as well as the return period of severe storms is critical for present coastal management, particularly given future rising sea-levels and that winter cyclone activity is projected to increase in the future in the North Sea region.  The return period for the major 1953 storm was thought to be ~50 years but may be less in the future. Whilst advances in hydrological modelling have been made to better predict peak storm-tide height along coastlines refinement requires better understanding of beach parameters and other coastal zone factors.  To achieve this also requires an understanding of how coastlines have responded to change over millennial time-scales.

This research will take a unique approach in combining documentary evidence (including ships logs), newly available climate reanalysis approaches and sediment dune archive data using novel portable luminescence datingto investigate past storm events in the North Sea.

For further information please contact Mark Bateman (m.d.bateman@Sheffield.ac.uk).

Glacial Advances of the Last British and Irish Icesheet

Recently huge advances have been made in understanding the retreat patterns of the Last British and Irish Icesheet (BIIS).  Retreat patterns have been targeted as conventional dating relies on when sediments were buried in the case of luminescence dating or rocks exposed in the case of cosmogenic dating after deglaciation. Direct dating of glacial diamicts is rare.  Additionally evidence of the age of sediments which were deposited just prior to glaciation are often assumed to have been eroded rendering them at best maximum ages of ice advances.  However if models of former and contemporary icesheets are to be improved knowledge of how the icesheets both grew AND shrunk is required to constrain them.

Building from the NERC funded Britice-Chrono project, this research will seek to develop luminescence based methods to directly date glacial diamicts both for the age of their deposition but also to extract the age of the sediment they picked up prior to deposition. From this it is hoped a regional pattern of advance and retreat can be reconstructed and used to refine the current understanding of the pattern of glaciation of the UK.

For further information please contact Mark Bateman (m.d.bateman@Sheffield.ac.uk).

Long-term evolution pebble beaches and their resilience to change

Imagine hearing the story of a beach pebble, the storm that brought it there and how long the beach has sat protecting its hinterland. Innovative new luminescence research is opening up the possibility of finding the age of pebble deposition for the first time. Why worry? Climate change is causing sea-level rise, more storminess and higher coastal erosion rates whilst coastal populations and infrastructure are increasing. 2013/14 saw UK coastal storms causing widespread flooding costing over £250 million. Dating old storm deposits and raised beaches would allow better understanding of longer-term sea level changes and the return periodicity and impact of past storm events.  This would allow key stakeholders to better mitigate this risk and protect the coastal environment.

This research will develop a proof of concept to luminescence date beach pebble deposition in order to better understand long-term beach evolution, sea-level changes and storm impacts.

For further information please contact Mark Bateman (m.d.bateman@Sheffield.ac.uk).

Comparing evidence and models of mountain glaciation in the British Isles

At the end of the last glacial period (~15 to ~11 thousand years ago), many of the mountainous regions of Britain and Ireland were covered by ice-masses. These ice-masses ranged in size from small cirque glaciers through valley glaciers to larger ice caps. Landforms (e.g. moraines, drumlins, cirques, roche moutonnees) and sediments (e.g. tills, glacial outwash) provide evidence for the behaviour of these ice-masses as they receded. Such palaeo-evidence may provide us with important analogues for our contemporary ice masses, which, due to the ongoing climate crisis, are also undergoing recession.

Here we aim to improve our understanding of palaeo-ice masses in the following ways: i) by using high-resolution numerical ice-flow models to replicate the behaviour of the now extinct British-Irish glaciers; ii) conduct fieldwork to expand the evidence-base regarding past ice behaviour; iii) undertake GIS and remote sensing studies; and iv) compare model predictions to geomorphological and sedimentological evidence.

For further information please contact Jeremy Ely (j.ely@sheffield.ac.uk).

How do gases drive volcanic activity?

Gases are known to play a key role in driving volcanism, for example by pressurising to generate explosions. However our understanding of the detail of this has been limited by a lack of observational data of sufficiently high temporal resolution to capture rapid degassing processes at the surface, for example explosions. Recently at Sheffield we have pioneered revolutionary low cost technology based on smartphone sensors, capable for measuring gas release every second.

In this project you will capitalise on this approach to gain unprecedented volcanic degassing data then use them to provided deeper insights into underground gas flow drives activity at the surface. This project could contain a mixture of fieldwork, laboratory and computational work on development of the instrumental hardware and software as well as data analysis, for instance with statistical methods. The project could be of interest to geoscience graduates, in addition to physicists or engineers.

For further information please contact Andrew McGonigle (a.mcgonigle@sheffield.ac.uk).

Transitioning of basaltic volcanic activity – from passive to explosive

Basaltic volcanism is one of the most common forms of volcanic activity on this planet, there is therefore a need to have a strong understanding of this style of activity. In particular, it is the understanding of the bubbles (and the gases which form these) and how they behave in the conduit between the different styles of basaltic activity which is crucial; from passive degassing generated by smaller near-spherical bubbles through to strombolian volcanism driven by longer gas slugs.

In this project you will have the opportunity to explore a number of avenues for understanding basaltic volcanic activity transitioning which could revolve around computational, laboratory-based, and fieldwork datasets. The project could be of interest to geoscience graduates or those with an interest in fluid dynamics.

For further information please contact Tom Pering (t.pering@sheffield.ac.uk).

Predicting the response of glaciers in High Mountain Asia to future climate change

The 2007 IPCC report (AR4) erroneously predicted the demise of Himalayan glaciers by 2035 CE, and highlighted the lack of observations and knowledge of glacier change in High Mountain Asia at this point in time. Since the publication of this report, an explosion in interest in this field has occurred, with a large number of international groups carrying out a diverse range of research projects to discover if high-elevation mountain glaciers behave as we would expect. Much new data has been gathered and many important processes controlling glacier mass change have been observed and quantified in detail. However, predictions of glacier change under IPCC climate change scenarios for 2100 CE and 2200 CE remain preliminary.

The next generation of glacier models are now needed to take a step forward and enable predictions of glacier change that align with the quality of equivalent climate model predictions. The development of such models requires the identification and representation of key processes that modify glacier behaviour through evaluation of analytical models and robust, representative field observations. There are a variety of PhD projects available in this theme exploring the geomorphology and dynamics of high-elevation mountain glaciers both in the field, in the laboratory and using numerical modelling.

For further information please contact Ann Rowan (a.rowan@sheffield.ac.uk).