Electromagnetic Measurements of Antarctic Sea Ice Thickness

Supervisor

James Reid (Earth Sciences, UTas), Tony Worby (AAD)

(PhD Only)

Project Outline

The Antarctic sea ice thickness distribution is an important parameter in models of global climate, and is at present poorly understood.  Long-term temporal changes in the sea ice thickness distribution are likely to be a sensitive indicator of global climate change.  Surface and airborne low-frequency electromagnetic (EM) induction methods have become widely used for sea ice thickness measurements in the Arctic, but have been applied only to a limited extent in the Antarctic.

A large proportion of the total volume of Antarctic sea ice is thought to be contained within three-dimensional structures such as pressure ridges.  Pressure ridges formed in Antarctic sea ice are generally smaller than those in the Arctic, and EM systems suitable for Antarctic sea ice mapping must be sensitive to relatively small variations in thickness.  Although EM methods have been found to yield reliable thickness measurements over level sea ice, rapid estimation of thickness at pressure ridges remains a significant problem in EM data interpretation.

The principal aim of this project will be to develop approximate two-dimensional and three-dimensional numerical models for the surface and airborne electromagnetic response of sea ice pressure ridges.   These models will initially be based on the inductive and resistive limits of the EM response, in order to be sufficiently rapid for practical multidimensional inversion of EM data from areas of deformed sea ice.

A secondary aim will be to establish the practical limitations of modern surface and airborne EM methods for sea ice thickness, via modelling and analysis of field data acquired in the Antarctic using a variety of frequency- and time-domain instrumentation.

The project will involve collaboration with researchers from the Alfred Wegener Institute, Germany and the Defence Science and Technology Organisation.

The preferred candidate will have strong background in physics, mathematics, geophysics or engineering.

Contact

Dr Tony Worby or tel +61 3 6226 2985