AusMT / surveys / KUTh Lake Leake 2008

KUTh Lake Leake 2008 BBMT

Magnetotelluric survey · Tasmania · Mineral Resources Tasmania

A broadband magnetotelluric line of 50.

About this survey

A broadband magnetotelluric line of 50.7 km on a bearing of 103 degrees was acquired along the Lake Leake Highway in eastern Tasmania between Campbell Town and Swansea, from 5 to 27 September 2008. Moombarriga Geoscience Pty Ltd acquired it for KUTh Exploration Pty Ltd, a subsidiary of KUTh Energy Ltd, as geothermal exploration on special exploration licence SEL26/2005, testing a zone where Devonian granite plutons are modelled to lie below 3 to 5 km of sediments and coincide with surface heat flow above 90 mW per square metre. Sites were occupied at a mean interval of 1.07 km. There was no distant remote reference on this line: the Oatlands remote station was not established until 1 October, after this line finished, so 50 of the 54 soundings were processed against another line site recording at the same time and the remaining four were processed single-site.

Recording used Phoenix Geophysics MTU-5A receivers with MTC-50 induction coils, on electric dipoles of 38 to 96 m, with a 50 Hz notch filter at 50 of the 54 sites. Ex, Ey, Bx and By were recorded at every site and Bz at 33 of the 54. Time series were written at three sample rates, 15, 150 and 2400 Hz, for a minimum of 16 hours at each site by the acquisition report and 12.4 to 67.5 hours with a median of 21.9 hours measured from the recording windows the files carry. Processing was the Phoenix SSMT suite, robust jackknife estimation after Jones and Jodicke with remote reference after Gamble, Goubau and Clark, followed by cross-power editing in MT-Editor, whose version the PROGVERS header names as 0.99.2.68 in 52 files and 0.99.2.88 in two.

This package serves the 54 cross-spectra transfer functions lodged for this line, one per occupied site, each carrying impedance on one common grid of 80 frequencies from 320 Hz to 0.00034 Hz, with the tipper published at the 33 sites where the vertical field was recorded. Two of the 54 are served here but withheld from the published products: at STL009A and STL041A the magnetic sensors were laid rotated against the electric dipoles while the spectra declare a zero rotation, so the frame the spectra are stored in cannot be determined from the file.

Data origin. The transfer functions served here are the 54 files of Southern2008/EDIs/STL_EDI/ inside Appendix7_MT_Data/Southern2008.zip in Mineral Resources Tasmania company report 09_5904, the KUTh Exploration annual report for 8 July 2008 to 7 July 2009, whose Appendix 7 is the magnetotelluric data and acquisition report 09_5904A (webdoc record id 88062, Evans, S., 27 October 2008) and whose Appendix 8 is the processing report 09_5904B (webdoc record id 88063, Manzella, A., June 2009). The release is open file under Creative Commons Attribution 3.0 Australia. The raw time series behind these files are in the same zip, under Southern2008/Time Series/, as 180 Phoenix TS3, TS4 and TS5 files covering 60 station runs with their recording tables and box and coil calibrations.

Data and downloads

Stations (52)

Contributors and organisations

Organisation

Mineral Resources Tasmania

Licence

CC BY 3.0 AU

Instruments

Phoenix Geophysics MTU-5A
Phoenix Geophysics MTC-50

Processing

Phoenix SSMT

Funding

KUTh Exploration Pty Ltd

Identifiers and provenance

Machine-readable survey record · catalogue schema mtcat 2.0