Desert dune avalanche processes in modern and ancient environments

Dr Jo Nield, Geography, University of Southampton, https://www.southampton.ac.uk/people/5x5p5c/doctor-jo-nield; Professor Ryan Ewing, Texas A & M University, https://geogeo.tamu.edu/people/profiles/faculty/ewingcryan.html; Dr Matthew Baddock, Loughborough University, https://www.lboro.ac.uk/subjects/geography-environment/staff/matthew-baddock/

PLEASE NOTE:  Application deadline date 08 Jan 2024.  Applications are no longer being accepted for this project

 

Project Overview 

This project will examine how wind-blown avalanches are imprinted on aeolian dune stratigraphy on Earth and Mars. It involves laboratory experiments, field work and planetary remote sensing. Ultimately the research outcomes will provide unique, cutting-edge insight into the influence of avalanche dynamics on aeolian dune migration, both modern and ancient.

 

Project Description 

Avalanching is responsible for wind-blown dune migration on Earth and Mars and because avalanches are preserved in dune stratigraphy, they are the most direct way that we can interpret past wind-climate conditions.  Recent evidence suggested avalanche magnitude is driven by grainfall dynamics which link to wind speed [1] and observations of avalanches have been made on a Martian [2].  However, without a better grasp of the process-form feedbacks between dune size and avalanche drivers, it is impossible to interpret the ancient wind climates that formed dune environments now preserved in the rock record both on Earth and Mars.  This PhD will use the latest technology to measure avalanches remotely and supplement field experiments with laboratory replicates within the SoGES aeolian avalanche slope facility. 

Field evidence will be collected from White Sands National Monument, New Mexico, and Great Sand Dunes, Colorado, USA.  Here you will undertake active process measurements, using terrestrial laser scanning (TLS) to characterize avalanche morphology and grainfall zone dynamics, along with sonic anemometry to measure flow and sediment samples for grain size analysis.  Climate conditions responsible for Jurassic-age avalanches (in Utah) will be reconstructed using TLS and grain size measurements, along with knowledge from the modern field and lab. Curiosity and HiRISE data will be used to measure Martian avalanches.

This PhD will make a significant contribution to our understanding of the feedbacks between dune migration and climate that will impact how we interpret modern and ancient desert environments and how we manage these environments in the future.

Location: 
University of Southampton, Highfield Campus
Training: 

The INSPIRE DTP programme provides comprehensive personal and professional development training alongside extensive opportunities for students to expand their multi-disciplinary outlook through interactions with a wide network of academic, research and industrial/policy partners. The student will be registered at the University of Southampton and hosted at Geography and Environmental Science. Specific training will

include: the use of TLS [1], 3D sonic anemometry [3], sediment transport measurements, grain size analysis, remote sensing techniques, ancient and modern environment interpretations [2], field skills, laboratory experimental avalanche slope techniques and large data set processing and analysis. The supervisory team are experts in desert landscape processes and together have extensive experience in undertaking effective field campaigns with high resolution process-form measurements.

 

Eligibility & Funding Details: 
Background Reading: 

Nield, J.M., Wiggs, G,F.S., Baddock, M.C., Hipondoka, M.H.T. (2017) Coupling leeside grainfall to avalanche characteristics in aeolian dune dynamics, Geology, 45(3): 271-274, doi: 10.1130/G38800.1.

 

Ewing, R.C., Lapotre, M.G.A., Lewis, K.W., Day, M., Stein, N., Rubin, D.M. (2017) Sedimentary processes of the Bagnold Dunes: Implications for the eolian rock record of Mars, Journal of Geophysical Research: Planets 122 (12), 2544-2573.

 

Baddock, M.C., Wiggs, G.F.S., Livingstone, I. (2011) A field study of mean and turbulent flow characteristics upwind, over and downwind of barchan dunes, Earth Surface Processes and Landforms 36 (11), 1435-1448