AusMT / surveys / Bowen Basin magnetotelluric survey 1976-80

Bowen Basin magnetotelluric survey 1976-80 LPMT

Magnetotelluric survey · Queensland · The University of Queensland

Between 1976 and 1980 the Department of Physics at the University of Queensland ran a magnetotelluric survey of the Bowen Basin in Central Queensland, on two traverses: a northern line of four sites west of Emerald and a southern line of eleven running east from Rolleston.

About this survey

Between 1976 and 1980 the Department of Physics at the University of Queensland ran a magnetotelluric survey of the Bowen Basin in Central Queensland, on two traverses: a northern line of four sites west of Emerald and a southern line of eleven running east from Rolleston. Field work was mainly in 1979 and 1980. The equipment was built in the department: four 300 metre telluric lines on ceramic porous pots filled with copper sulphate solution, three orthogonal coils, and a twelve-bit CMOS datalogger recording to cassette tape, processed by the cross-frequency method on a PDP-11/34. Fifteen sites carry a tabulated response, over a band from 2 seconds to 7,943 seconds. This package carries 15 EDI transfer function files minted from Appendix I of Dekker (1983), a University of Queensland doctoral thesis, with positions from its Appendix E. What the thesis tabulated is apparent resistivity and phase in the two off-diagonal modes only, together with a standard deviation on each log10 resistivity; the impedance published here is reconstructed from those columns. The thesis tabulates no impedance tensor element, no diagonal term, no tipper, no phase error, no coherence and no skew anywhere, so the diagonal elements are written as the EDI empty sentinel and no vertical magnetic channel is declared. The two modes are populated independently and 103 of the 256 published period rows carry one mode alone; a blank in the printed table means absent and never zero. Two readings had to be settled that the thesis itself does not settle, and both are declared in every file. The coordinates carry no datum anywhere in the thesis and are published on the assumption of AGD66, carried as an assumption and never transformed; they are printed to degrees and whole or half minutes, so the positional precision is 30 arc seconds, about 0.93 kilometres. The tabulated sigma is treated as one standard deviation of log10 apparent resistivity, while the thesis elsewhere describes its results as carrying a confidence interval of two standard deviations, and the choice changes every uncertainty by a factor of two. The values are in the magnetic frame the survey recorded them in and no declination rotation is applied, because the thesis prints no declination. Three further located occupations, Underwood, Spotswood Creek and Ban Ban Springs, carry a printed position but no response anywhere in the thesis and are not published here; no response is fabricated for them. The organisation recorded against this package, The University of Queensland, is its custodian of record: that field states who holds and releases these files, not who operated each instrument in the field.

Data and downloads

Stations (15)

Contributors and organisations

Organisation

The University of Queensland

Licence

CC BY 4.0

Publications

Dekker, D.L. (1983). A magnetotelluric survey of the Bowen Basin. PhD thesis, University of Queensland, Department of Physics. 10.14264/29fd91e

Dekker, D.L. and Hastie, L.M. (1981). Sources of error and bias in a magnetotelluric depth sounding of the Bowen Basin. Physics of the Earth and Planetary Interiors 25(3): 219-225. 10.1016/0031-9201(81)90064-9

Identifiers and provenance

Machine-readable survey record · catalogue schema mtcat 2.0