b'Geophysics in the surveysNewsGeological Survey of South Australia: A new way to access geophysical data onSARIGThousands of geophysical surveys haveinterest but this time, click the AdvancedThe geophysics team at the GSSA are been acquired over South Australia.Search option at the bottom left of theroutinely adding historic and more Many hundreds of these are airbornescreen (you may have to scroll down) andrecent surveys to these layers. If you surveys, notably magnetic, radiometric,follow the prompts. This second methodcant find a survey you know existsor and electromagnetic surveys. In thewill cookie-cut the survey to the boxsee no surveys in your area of interest past the government of South Australiayou drew on the screen, and has options be sure to try a fourth method and has presented the survey boundariesfor downloading multiple types ofcheck any open file envelopes in that of all these surveys on a single map ofgeophysical data in either grid or locatedarea. One way to do this is to first the state. They are now also visible ondata (ASCII format) for multiple surveysdetermine any previous Exploration SARIG (https://map.sarig.sa.gov.au/) viain your choice of coordinate system andLicences in your area of interest using a time slice tool, grouped together indatum. Additionally, this method willSARIG. Then click the burger menu in blocks of surveys acquired in five-yearallow the user to download selectedSARIG (the three horizontal lines near intervals. columns of ASCII data, and to resamplethe top) and click on Georeference. Click grids to every 2nd or 10th grid cell. on Advanced Search under Mineral There are four main options to downloadcompany exploration reports, and type survey data and grids. The first wayThis second method may struggle withthe Exploration Licence number next to involves using the Spatial Search optionlarger downloads. Somewhere aroundTenements (it should be in the format and selecting Active layers from the3GB our servers struggle with theEL01234). Links to open file envelopes drop-down menu (ensuring first thatprocessing load. If youve requested acan be found on the results page. Many Geophysical Surveys is an active layer).download and havent received an emailsmaller surveysincluding gravity and use the Draw Area tool to draw a box onwithin a few hours, please try anotherground magneticsare often simply the survey youre interested in, and a pop- method or contact our customer servicespaper clipped to the pdf, and have not up window will emerge from the bottomteam. yet made it to the spatial layers.of the screen. The pop-up window will include a link to the survey data andThe third method also involves a directMany surveys remain that havent yet metadata. Clicking the link will take youlink to the data. From the initial SARIGbeen added to the various layers on to a Geonetwork page, which includes ascreen, click on Map Layers and startSARIG but we are confident that there is blue Download data package button.typing geophysical surveys in the textample information available on SARIG Surveys downloaded using this optionbox. Switch on Geophysical Surveysto hunt anything down. If you require will contain all of the company suppliedby clicking the box, and then selectassistance with downloading geophysical and GSSA processed data, grids andthe Identify tool under Action in thedata on SARIGplease do not hesitate to contractor reports in a single download.middle of the screen. Click on the mapcontact Customer Services on resources.These data packages are stored on theat your area of interest and any email@example.com.Cloud using Amazon Web Services. intersecting the clicked area will be listed on the left-hand-side of the screen. The second method involves using theExpanding any of these items will revealPhil Heath and Laz Katona Spatial Search option and selectinga hyperlink that will allow you to directlyGeological Survey of South Australia Geophysical Data from the drop-downdownload the complete data package firstname.lastname@example.org menu. Again, draw a box in your area ofthat survey. Laz.Katona@sa.gov.auPlanned new seismic data acquisitionIlluminating the detailed 3D seismicshear zones, etc.) needed for robustsensors will faithfully record ground velocity structure of the lithosphere wasprospectivity mapping. Dense seismicmotion at frequencies between 100 Hz identified by the uNCOVER initiativearrays (WOMBAT) in the southeast ofand 120s, and between 100 Hz and 25s, as a key element for enhancing thethe state have helped to mitigate thisrespectively.probability of successful mineraldeficiency, but the band-limited sensors exploration under cover. To this end, thewere insensitive to the data-rich lowGiven the relative seismic quiescence of GSSA is poised to deploy the AusArrayfrequency surface waves that are athe Australian continent, the tomography SA broadband seismic array across themainstay of probing lithospheric velocitymodelling will draw predominantly on eastern-central Gawler Craton. structure. two energy sources: (i) ballistic waves from distant (teleseismic) earthquakes, Existing broadband seismic dataThe AusArray SA seismic array is designedand (ii) the diffuse, ambient noise field.from sparse arrays in South Australiato acquire broadband data across the (e.g., SKIPPY, SOC, BILBY) illuminateeastern-central Gawler Craton at theSurface waves transit trapped near the lithospheric structure at a lengthsame station spacing (0.5 x 0.5) as theEarths surface and are dispersive, i.e., scale of 3 x 3. However, this isAusLAMP magnetotelluric (MT) array.their velocity varies with frequency. Their insufficient to delineate the detailedThe array will comprise 29 Nanometricsdispersion is due to their increasing lithospheric architecture (terraneTrillium Compact 120s sensors (25depth sensitivity with decreasing margins, metasomatic fingerprints,from ANSIR; 4 from GA) and 12 Trilliumfrequency (or equivalently, with trans-lithospheric faults, sutures andCompact 25s sensors (from ANSIR). Theseincreasing period). Surface (Rayleigh) 17 PREVIEW JuNE 2020'