Radar suitability in aeolian sand dunes: a global review

Over the past 40 years, GPR has been used to image the internal architecture of aeolian sand dunes with generally impressive results. These data may be used to produce high resolution models of dune structures, useful in the study of dune migration rates, desertification, as palaeo-environmental indicators and for the construction of petroleum reservoir analogues. Although published works suggest that dry sands are ideal radar environments, practical experience in deserts around the world indicate that maximum penetration depths are highly variable. The factors which influence radar suitability appear to include moisture in the dune core, the presence of conductive evaporates drawn upwards from the dune base through capillarity, surface salinity on coastal dunes, the presence of vegetation, and the lithology of the source rocks. We herein discuss these factors, whilst comparing our results of standardised radar penetration tests from sand bodies in Algeria, Australia, Brazil, Libya, Madagascar, Namibia, Oman, and South Africa.