Aeolian dune field dynamics on Mars
Applications are invited for a funded PhD studentship tenable in the Faculty of Life and Health Sciences at the
All applicants should hold a first or upper second class honours degree in Geology, Geography, Earth or Atmospheric Sciences or related area.
The High Resolution Imaging Science Experiment (HiRISE) on board the Mars Reconnaissance Orbiter (MRO) now presents an excellent dataset with which to examine dune landscapes on the surface of Mars. Recent active surface processes have been confirmed but many of the dunefields we see on Mars have an inherited landscape evolution possibly stretching back 5GA years. Current thinking into how dunefields have evolved on Mars is limited and we still do not know the answer to important landscape questions such as how dunes evolved in particular locations and how they may have migrated in certain directions at various timescales and by forcing events/regimes.
Dunes on Mars have been used to infer directional components of regional wind regimes operating within and over dunefields . These studies generally assume dune orientation as being representative of modern wind patterns operating today. However topography may be an important control on the location, and residency of dunefields. Particularly in the southern hemisphere of Mars, dunefields are a) sourced from sediments locally in craters and b) currently reside inside those same craters. High resolution imagery form the HiRISE dataset showing extremely fine surface resolution of ripple features on sand dunes within Proctor crater, Mars. Therefore, if we are to use dunes as proxy wind vanes for atmospheric insights, we must first understand the setting of the dunefields themselves. For example,e we need to understand the topographical ‘accommodation space’ (e.g. crater or valley locations) where these dunes are currently located and if this has been a major factor in controlling the evolution of the dunefields themselves. Other factors such as sediment origin and supply are still very much environmental conundrums that
we need to resolve fully.
HiRISE imagery now enables generation of 3-D Digital Terrain Surfaces at these dunefield locations and their surrounding areas. We can use this to simulate detailed patterns of 3-D wind flow behaviour to help understand the limitation of the accommodation space’s topography to house dune landforms under particular wind conditions. Modelling of airflow [2, 3] also enables multiple magnitude and direction scenarios to be studied at various locations on Mars with latitudinal and associated climatic variations. Computational Fluid Dynamic modelling of airflow over dune ridges inside Proctor crater, Mars.
A significant finding of the MRO mission is the confirmation of active surface processes [4, 5] under the current Mars climate. Many of these processes particularly in the polar region are linked to seasonal volatile and wind cycles, such as the migration of aeolian bedforms, avalanches of CO2 ice from polar cliffs and formation of new gullies. This project will investigate the influence of topography of the accommodation space on enhancing or limiting the sediment storage regime of martian dunefields across a range of terrain types. Including Craters, troughs, chasma and open plains. Particular dunes types on Mars such as transverse ridges, barchanoids and domes will be examined and compared with Earth analogues. Existing NASA-funded research led by co-supervisor Dr Bourke (TCD) will supplement this PhD project.
The overall aim of the project is to describe and understand the evolution of aeolian dunefield dynamics on Mars under particular topographical controls
Successful candidates will enrol as of September 2016, on a full-time programme of research studies leading to the award of the degree of Doctor of Philosophy.
The studentship will comprise fees together with an annual stipend of £14,296 and will be awarded for a period of up to three years subject to satisfactory progress.
The closing date for receipt of completed applications is 26th February 2016.
Interviews will be held during March 2016.
Further information may be found at - http://www.science.ulster.ac.uk/gradschool/environmental/
if you wish to discuss this topic or receive advice on research please contact Professor Derek Jackson
Coastal Systems, Environmental Sciences Research Institute, Ulster University
Tel: +44 (0)28 7012 3083
For more information on applying go to ulster.ac.uk/research
Apply online ulster.ac.uk/applyonline