Magnetotelluric Broadband Surveys of Western and North-Western Tasmania, 2016

Brief description

This record was harvested by RDA at 2025-05-09T16:34:41.775+10:00 from NCI's Data Catalogue where it was last modified at 2023-05-02.

Full description

Two broadband MT traverses were acquired for shallower investigations of the lithosphere beneath western and north western Tasmania. These surveys transected major crustal boundaries between Precambrian Tyennan basement and the highly metalliferous Cambrian to Devonian Dundas-Fossey Trough. The MT instruments used for these broadband transects were sourced through the Australian National Seismic Imaging Resource (ANSIR) national Earth sounding instrument pool. Co-funded by AuScope and maintained by the University of Adelaide, the instrumental capability results from a collaboration between the University of Adelaide and Geoscience Australia. Each instrument consists of a 24-bit 6-channel PR6-24 Earth Data Logger housed in a reinforced Pelican case. The logger records GPS-synchronised time series electric field data from an array of three Petiau-type lead chloride non-polarisable electrodes. Magnetic field time series data are recorded from LEMI-120 induction coil output when in broadband survey mode. Powered by a 70 amp-hour 12 volt battery, the unit can log broadband data for ∼3 days without a recharge or battery replacement. Based out of Queenstown, data acquisition on the eastern end of the western transect commenced on 22nd January 2016. A remote reference site was established 5 km east of the easternmost proposed transect site. Occupation time at each site was in the order of 36-48 hours with crews deploying and retrieving two sites per day. Acquisition of all western transect sites was completed by the 6th of February, at which point field crews rotated staff and relocated to Gowrie Park in northern Tasmania to commence acquisition on the northern transect. Data acquisition on the northern transect commenced on the 8th of February 2016 starting at the northernmost site near Forth following the establishment of a remote reference site some 4 km south of Beulah and 20 km east of the transect line. Acquisition on the northern transect was hindered by wildlife chewing and severing electrode cables early in deployment at four sites, three requiring a single redeployment and one requiring two re-deployments with progressively deeper burial of cables, electrodes and magnetometers. Acquisition on the northern transect was completed on the 19th of February.

Credit

This dataset was supported by Mineral Resources Tasmania.

The Geophysics 2030 project received co-investment from AuScope and the Australian Research Data Commons (ARDC) to support the data curation at the National Computational Infrastructure (NCI Australia) (https://doi.org/10.47486/XN002). AuScope, the ARDC and NCI Australia are enabled by the National Collaborative Research Infrastructure Strategy (NCRIS).

Lineage

Data principally acquired and processed by Thomas Ostersen as part of his PhD research undertaken at the University of Tasmania, sponsored by Mineral Resources Tasmania, Geoscience Australia, the University of Adelaide and AuScope. Full details can be found in his thesis 'Geoelectric Structure of the Tasmanian Lithosphere from Multi-Scale Magnetotelluric Data' (http://dx.doi.org/10.25959/100.00037925) and field operations report (https://www.mrt.tas.gov.au/webdoc2/app/default/document_domrept_detail?id=119226).