TY - JOUR A1 - Ley-Cooper, Alan Yusen A1 - Viezzoli, Andrea A1 - Guillemoteau, Julien A1 - Vignoli, Giulio A1 - Macnae, James A1 - Cox, Leif A1 - Munday, Tim T1 - Airborne electromagnetic modelling options and their consequences in target definition JF - Exploration geophysics : the bulletin of the Australian Society of Exploration Geophysicists N2 - Given the range of geological conditions under which airborne EM surveys are conducted, there is an expectation that the 2D and 3D methods used to extract models that are geologically meaningful would be favoured over ID inversion and transforms. We do after all deal with an Earth that constantly undergoes, faulting, intrusions, and erosive processes that yield a subsurface morphology, which is, for most parts, dissimilar to a horizontal layered earth. We analyse data from a survey collected in the Musgrave province, South Australia. It is of particular interest since it has been used for mineral prospecting and for a regional hydro-geological assessment. The survey comprises abrupt lateral variations, more-subtle lateral continuous sedimentary sequences and filled palaeovalleys. As consequence, we deal with several geophysical targets of contrasting conductivities, varying geometries and at different depths. We invert the observations by using several algorithms characterised by the different dimensionality of the forward operator. Inversion of airborne EM data is known to be an ill-posed problem. We can generate a variety of models that numerically adequately fit the measured data, which makes the solution non-unique. The application of different deterministic inversion codes or transforms to the same dataset can give dissimilar results, as shown in this paper. This ambiguity suggests the choice of processes and algorithms used to interpret AEM data cannot be resolved as a matter of personal choice and preference. The degree to which models generated by a ID algorithm replicate/or not measured data, can be an indicator of the data's dimensionality, which perse does not imply that data that can be fitted with a 1D model cannot be multidimensional. On the other hand, it is crucial that codes that can generate 2D and 3D models do reproduce the measured data in order for them to be considered as a plausible solution. In the absence of ancillary information, it could be argued that the simplest model with the simplest physics might be preferred. KW - airborne KW - electromagnetics KW - exploration KW - inversion KW - target Y1 - 2015 U6 - https://doi.org/10.1071/EG14045 SN - 0812-3985 SN - 1834-7533 VL - 46 IS - 1 SP - 74 EP - 84 PB - CSIRO CY - Clayton ER - TY - JOUR A1 - Hurley, Andrew Wright A1 - Schwarz, Anja T1 - "The greatest son of our Heimat": reading German Leichhardts across the National Socialist era JF - Journal of Australian studies N2 - The article discusses German commemorations of Ludwig Leichhardt (1813-1848) in the National Socialist era when officials, journalists, educators and writers, spurred by the double anniversary of the explorer's 125th birthday and the 90th anniversary of his disappearance, began to re-imagine the explorer's life and fate in the light of the ideological imperatives of the day. Our analysis of this period pays particular attention to how these reimagined Leichhardts emphasise or neglect some of the key elements that make up his story to this day, among them: Leichhardt's ethnicity; his sense of attachment to place and home; his homosocial relationships; his evasion of Prussian military service; his role in the British colonial project; and finally, his engagements with Aborigines. On the one hand, our analysis reveals, how Leichhardt was portrayed first on the local and, later, the national level in ways that increasingly sought to elide ambiguous aspects of his life and deeds. However, it also uncovers some of the ideological labour required to render him useful to the National Socialist cause. Often enough, these re-imagined Leichhardts escaped party politics, and cast up some of the logical inconsistencies and limits to key terms in National Socialist thinking. KW - Ludwig Leichhardt KW - National Socialism KW - exploration KW - German colonialism KW - memory studies Y1 - 2015 U6 - https://doi.org/10.1080/14443058.2015.1076025 SN - 1444-3058 SN - 1835-6419 VL - 39 IS - 4 SP - 529 EP - 545 PB - Routledge, Taylor & Francis Group CY - Abingdon ER -