skip to primary navigationskip to content
 

E425: Impact cratering: from dynamics to morphology (Lead Supervisor: Jerome Neufeld, DAMTP)

Supervisors: Jerome Neufeld (DAMTP) and Stuart Dalziel (DAMTP

Importance of the area of research:

Impact cratering is an important process that has played a key role in large climatic transients on Earth, with major ramifications for planetary biodiversity.  Furthermore, the dynamics of impact cratering provides clues as to early crustal structure and the distribution of mineral resources.  On other planetary bodies, the morphology of impact craters varies between small “simple” craters with roughly parabolic interior profiles, to larger “complex” craters with single or multiple central peaks, flat inner floors, and terraced rims (Melosh & Ivanov, 1999). Current numerical simulations, used to infer planetary properties, rely on simulating the flow of yield-stress fluids during impact (Brandon et al, 2016).  New laboratory experiments provide an opportunity to test a wider array of impact parameters with a faithful representation of yield-stress rheology during impact, and provide validation for simulations and much needed insight to develop accurate simplified mathematical models.

Project summary:

This project will explore the wide range of observed morphological features, and the dynamics leading to them, through advanced high-speed imaging of the impact of a yield-stress fluid. Yield-stress fluids, such as carbopol (the main ingredient of hair gel), act as a solid until subject to a sufficient stress, after which they flow as a fluid.  In trial experiments, the impact of a droplet of such a fluid relaxes to a series of non-trivial shapes for different impact velocities and sizes, largely mimicking the wide range of phenomena observed in planetary craters.  Understanding the processes that form these different morphologies, and how to model them, will provide valuable insight into the geological process. 

What the student will do:

The student will conduct a suite of systematic experiments using a high-speed camera to track the motion of tracer particles in a yield-stress fluid in order to image deformation during impact and relaxation to the final state.  Profiles of the evolving laboratory craters will be imaged using laser profilometry, and the rheology of the working fluids measured in the laboratory rheometer.  The student will use, test and inform the development of mathematical models necessary to understand the wide variety, morphology and genesis of planetary impact craters. Opportunities also exist for the student to undertake numerical simulation of the impacts.

Please contact the lead supervisor directly for further information relating to what the successful applicant will be expected to do, training to be provided, and any specific educational background requirements.

References:

Melosh, H.J., Ivanov, B.A. (1999). Impact crater collapse. Ann. Rev. Earth Planet. Sci., 27, 385-415

Brandon et al. (2016). Formation of the Orientale lunar multiring basin. Science, 354, 441-444.

 

 Follow this link to find out about applying for this project.

Other projects available from the Lead Supervisor can be viewed here.

Filed under: