Abstract : Despite significant progresses in the understanding of the formation and propagation of pressure waves in the open atmosphere in the past decades, experience form past accidents (AZF, Toulouse, 2001, Billy-Berclau, 2003 and even Buncefied 2005) reveals that overpressure levels may be greatly ill estimated. This is obviously a concern when the protection of citizens is concerned. There are some indications that both the topography and weather conditions may play a significant role but this remains rather qualitative and there is a need to clarify such points. In this paper, the results of a preliminary experimental campaign are presented in which up to 500 kg eq TNT was detonated in the open atmosphere and the pressure field measured up to 10 kms.
