Star dunes: Global distribution, characteristics and formation

Abstract

<p>The distribution, characteristics and formation of mega-dune forms (esp. star dunes) is, compared to smaller dune forms, for example barchans and linear dunes, much more complex and still poorly investigated. Although occurring globally nearly in all sand seas (ergs), due to their location in often remote and hyper-arid environments and their complexity, they are highly underrepresented in recent research. Last methodological research and reviews, apart from regional case studies (e.g. Zhang et al. 2016), were published decades ago (e.g. Lancaster 1989). In consequence, definitions and development theories remain more or less constant over time, describing star dunes of pyramidal shape with three to four arms, of significant size and mostly situated in depositional centers. Recognized by most researcher, their formation seems to be bound to a regional wind system with a high directional variability by concurrent and sufficient sediment availability. However, a modern assessment of the global star dune distribution is missing.</p><p>Therefore, we will present first results of an analysis of global star dune occurrence and distribution via freely available and also highly resolute satellite data provided by Google Earth and ESRI base map services in order to summarize their locations, morphometric characteristics as well as their environmental setting and to explore similarities and differences. Overall, an assessment of a global star dune inventory can lead to a more precise morphometric description, definition, and a better comparison of these dune forms and therefore can contribute to a better understanding of their evolution.</p><p>Lancaster, N. (1989). Star dunes. Progress in Physical Geography 13, 67-91.</p><p>Zhang, W., Qu, J., Tan, L., Jing, Z., Bian, K. and Niu, Q. (2016). Environmental dynamics of a star dune. Geo­morphology 273, 28-38.</p>