b'Environmental geophysics scientist-artist Sean Chua to perform a short snippet of Sounds of Australias Geology at the recent 2019 Australasian Exploration Geoscience Conference gala dinner held in Perth. The team worked on composing EMusic pieces by sonifying extracts from several of GAs airborne electromagnetic (AEM) datasets, some from AusAEM the worlds largest airborne EM survey (http://www.ga.gov.au/eftf/minerals/nawa/ausaem). AEM surveys have traditionally been collected to underpin mineral exploration, agriculture and environmental resource management. GA was delighted to find new and innovative ways of using its AEM data,and to broadly communicate theimportance of the science and research coming out of these geophysical datasets.The audience who attended the Sounds of Australias Geology concert, heldFigure 2.The band performing Sounds of Australias Geology at Geoscience Australia.in the Sir Harold Raggatt Theatre at Geoscience Australia, enjoyed a full visual and audio performance (FiguresThe second half of the first track has aFigure 4 shows an example of how the 1 and 2). The audience learned aboutreversed travel, hence going from thelink between the EM data and music is geophysics, geology, remote sensing anddeepest layers toward the surface. Duringachieved. In this case, the EM sounding musical structures through scales, chordsthis track, the saxophonist Guidolottiwas taken from a data set flown over and improvisation. Brief descriptionsbegan to interplay with the pure EMusicthe Menindee Lakes. The response was of contextual geology and the in situbase, following the exact pitches andgrouped and then split into three parts geophysical responses followed thescales of the Yilgarn/ Albany-Fraserthat are associated with different layers. musical pieces from locations in Figure 3. orogeny. The first layer, named Sand Dunes, is The first track of the concert showedbased only on two pitches, and related the sonification of AEM data collectedThe performance continued to exploreto the thin and resistive features of this over the Yilgarn craton. It was anthe concepts of geological formationsshallow formation. In contrast, the high introductory piece that was arrangedand time across the four landscapesconductivity of the Blanchetown Clays as a composition of pure EMusic (i.e.selected by Dr Yusen Ley-Cooper,in the second layer allowed the capture the simple sonification of the EM datashowing peculiar moods, in some wayof many more pitches, which have a direct to its mapped chords, withoutreflecting the regions features. chromatic cadence, following the slow any involvement by the musicians). The execution times of the pitches are strictly linked to the acquisition times of the TEMPEST gates, provided that an expansion time of 1 million was applied in order for the single pitches to be heard.A representative example of an AEM sounding from the Yilgarn/Albany-Fraser orogeny, in the proximity of the Tropicana deposit is represented in Table 1. The table shows the relationship between the Earths response measured in femto Teslas, and the audible frequencies, i.e. the musical notes. Each note is paired with one of the 15 sampling windows used in the TEMPEST system. Each window probes simultaneously deeper into the ground, until eventually the EM signal is defusedFigure 3.Locations around Australia with AEM coverage; the Kimberly, Menindee Lakes, the Red Centre, and turns into noise, in this case, afterand the mineral endowed Albany-Fraser/Yilgarn, selected for EMusic sonification, presented at the Sounds window 13. of Australias Geology concert.45 PREVIEW DECEMBER 2019'