Desert dune avalanche processes in modern and ancient environments

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.

From the stratigraphic record in ancient and modern dunes, we can observe variability in avalanche deposit thickness, slope and grainsize distribution.  Recent evidence from a 5 m barchan suggested avalanche magnitude is driven by grainfall dynamics which link to wind speed [1] and observations of avalanches have been made on a Martian barchan visited by Curiosity [2].  However, evidence is lacking on the extent this theory holds for dunes of different heights and grain size.  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.  Previous attempts to investigate avalanche dynamics have been hampered because slopes are unstable for mounting instruments.  This PhD will use the latest technology to measure avalanches remotely and supplement field experiments with laboratory replicates.

Ultimately the research outcomes will provide unique, cutting-edge insight into the influence of avalanche dynamics on aeolian dune migration, both modern and ancient.

For full project details visit the Inspire project page.