AusMT / surveys / Skippy-3 Array 1994

Skippy-3 Array 1994 GDS

Geomagnetic depth sounding survey · Northern Territory · Australian National University

Part of the Australia legacy GDS collection

In 1994 ten three-component magnetometer stations recorded across most of the Northern Territory, from the Top End to below the Tropic of Capricorn and from the Western Australian border to the Queensland border, at spacings of hundreds of kilometres.

About this survey

In 1994 ten three-component magnetometer stations recorded across most of the Northern Territory, from the Top End to below the Tropic of Capricorn and from the Western Australian border to the Queensland border, at spacings of hundreds of kilometres. Liejun Wang's 1998 catalogue of Australian magnetometer arrays lists the array as "Skippy Project, ANU, 1994", and his database records it as the "Skippy-3 Array". Every other array in that catalogue names the target it was aimed at. SKIPPY was not a target but a programme: the Australian National University's portable broadband seismic experiment, run by its Research School of Earth Sciences to map the three-dimensional seismic structure of the lithosphere and mantle beneath the whole continent from earthquakes on the surrounding plate boundaries (van der Hilst, Kennett, Christie and Grant 1994). Rather than occupy more than sixty sites at once, the school moved arrays of up to twelve portable recorders around the continent at roughly 400 km spacing, six arrays in all between January 1993 and December 1996 (AusPass). The third array ran from May to October 1994 and was planned as ten stations in the north (van der Hilst et al. 1994), which this magnetometer array matches on date, region and number of sites. Neither source names a magnetometer, and no positions are published for the seismic stations, so the match is consistent with the record rather than confirmed by it. The magnetic array's own purpose, operators and dates were never recorded, and the name is all that points to that deployment. Nine of its ten site numbers recur as serials of the Flinders University digital fluxgate magnetometers of Francois Chamalaun and Bob Walker: AusMT's reading, not a record.

No result from the array was ever published, and no later study is known to have used it. No published figure or table of Skippy-3 values exists to check the served arrows against; nothing else of the array survives. The station positions are registered only to a kilometre or worse.

The served values are induction arrows at seventeen periods from 389 to 27,307 s (6.48 to 455.11 minutes in the register) for each of the ten stations, taken from the reference code 6 rows, station ids 163 to 172, of Liejun Wang's Australian Electromagnetic Database. The register prints one standard error on each arrow radius and on each arrow angle, and those uncertainties travel with the values at every station but s17, whose arrows carry a constant placeholder variance instead; the coordinates are the register's own, given to one or two decimals. The array itself is catalogued only in Wang (1998), PhD thesis, Australian National University, hdl:1885/145955, at Table 2.1 on page 20 and Table 2.7 on page 29, and whether he was given the values or digitised them is not stated. The original recordings are not held.

Data and downloads

Stations (10)

Contributors and organisations

Organisation

Australian National University

Licence

CC BY 4.0

Identifiers and provenance

Machine-readable survey record · catalogue schema mtcat 2.0