Brief description
Airborne electromagnetics (AEM) is a geophysical technique used for estimating the bulk conductivity profile of the upper 300 m (approximately) of the subsurface. The AEM data acquired as part of the Exploring for the Future program AusAEM Eastern Corridor survey (Ley-Cooper 2021) covers much of the central Kati Thanda - Lake Eyre Basin (KT–LEB). Data for these regional surveys were acquired using the TEMPEST AEM system at a nominal 20 km line spacing.
The prevalence and relative consistency of large sand-rich sediment zones across the Cooper Creek Palaeovalley (Evans et al. 2024) means that AEM data are potentially useful for inferring the distribution of groundwater salinity beneath the floodplain and surrounds. To visualise salinity from AEM data in a map, the thickness weighted average bulk conductivity was calculated for the 15 m depth interval beneath the watertable along the AEM survey lines. Symington et al. (2024) details the rationale and methods to produce the AEM bulk conductivity points. Symington et al. (2024) also included the code embedded in a jupyter notebook written to calculate bulk conductance points from AEM line data and undertake an uncertainty analysis to assess the likelihood of the conductance response to be related to groundwater (note that the link to the code is contained in the Symington et al. 2024 reference).
In conjunction with sparse groundwater salinity and water level data from existing bores, Symington et al. (2024) used the conductance data to provide insights to address the following questions:
1. What is the regional scale distribution of groundwater salinity within the shallow alluvial aquifer?
2. Where does the shallow aquifer host fresh water?
3. What areas are most likely to receive recharge from the flanks of the floodplain?
4. Is there evidence for the groundwater discharging into the river?
Data from Symington et al. (2024) were used to infer salinity across the Cooper Creek floodplain and Strzelecki Desert, as well as to determine the location of potential fresh groundwater lenses beneath Cooper Creek floodplain in SA and Queensland. The groundwater bore and uncertainty analysis suggests good correlation exists between groundwater bore data and AEM conductance points, where groundwater occurs at shallow depths in areas including the Cooper Creek floodplain, Strzelecki Desert, and Coongie Lakes. Data analysis, interpretation and results are in Symington et al. (2024) and further discussed in Evans et al. (2024), Symington et al. (2023) and Symington et al. (2022).
References
Evans TJ, Bishop C, Symington NJ, Halas L, Hansen JWH, Norton CJ, Hannaford C and Lewis SJ (2024) Cenozoic geology, hydrogeology, and groundwater systems: Kati Thanda – Lake Eyre Basin, Record 2024/05, Geoscience Australia, Canberra, http://dx.doi.org/10.26186/147422.
Ley-Cooper AY (2021) Exploring for the Future AusAEM Eastern Resources Corridor 2021 Airborne Electromagnetic Survey TEMPEST® airborne electromagnetic data and GALEI inversion conductivity estimates [data set], Geoscience Australia, https://ecat.ga.gov.au/geonetwork/srv/api/records/145744, accessed 14 December 2023.
Symington N, Evans T, McPherson A, Buckerfield S, Rollet N, Ray A and Halas L (2024) Characterising surface water groundwater interaction using airborne electromagnetics: a case study from the Cooper Creek floodplain, Queensland, Australia, workflow release, Geoscience Australia, Canberra, https://dx.doi.org/10.26186/149176.
Symington N, Evans T, Rollet N, Halas L, Vizy J, Buckerfield S, Ray A, LeyCooper Y and Brodie R (2023) Using regional airborne electromagnetic conductivity data to characterise surface water groundwater interaction in the Cooper Creek floodplain in arid central eastern Australia, Geoscience Australia, Canberra, https://pid.geoscience.gov.au/dataset/ga/147716.
Symington N, Halas L, Evans T and Rollet N (2022) Mapping freshwater lenses in the Cooper Creek floodplain using airborne electromagnetics, Geoscience Australia, Canberra, https://pid.geoscience.gov.au/dataset/ga/147039.
Lineage
Maintenance and Update Frequency: asNeeded
Statement:
Data lineage, processing code, workflows, and workflow methodology are described in Symington et al. (2024).
Notes
PurposeThis data package contains several airborne electromagnetic (AEM) and associated datasets from the Cooper Creek floodplain AEM case study undertaken as part of the activity to assess the Cenozoic geology, hydrogeology, and groundwater systems of the Kati Thanda – Lake Eyre Basin. This activity was part of the National Groundwater Systems (NGS) project in the Exploring for the Future program and used the Eastern Corridor AusAEM survey dataset. The data package also contains data showing the interpreted position of 14 fresh groundwater lenses at various locations beneath the Cooper Creek floodplain and surrounds as interpreted from AEM data.
Created: 31 08 2024
Issued: 25 11 2024
Data time period: 2021-01-01 to 2021-12-31
text: westlimit=139.253; southlimit=-29.431; eastlimit=144.3221; northlimit=-24.55968; projection=GDA94 / geographic 2D (EPSG: 4283)
Subjects
AEM bulk conductivity |
AusAEM |
AusAEM interpretation |
Cooper Creek floodplain |
EFTF – Exploring for the Future |
Electrical and electromagnetic methods in geophysics |
Groundwater hydrology |
Kati Thanda - Lake Eyre Basin |
National Groundwater Systems |
Published_External |
airborne electromagnetic survey |
data processing |
data workflows |
fresh groundwater lenses |
geoscientificInformation |
groundwater recharge |
groundwater salinity |
uncertainty analysis |
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Other Information
Download the data (zip) [9.1 MB]
uri :
https://d28rz98at9flks.cloudfront.net/149839/149839_00_0.zip
Identifiers
- DOI : 10.26186/149839
- URI : pid.geoscience.gov.au/dataset/ga/149839
- global : 762d5faf-a7e1-4ee4-9e2b-35f74e6536b8
