MINQ
Mt Isa - Northern Queensland
(MINQ) Passive Seismic Experiment
Sites
The MINQ experiment is being conducted by the Australian National University and the Geological Survey of Queensland as part of the AuScope Infrastructure program.
The grid of portable earthquake recorders are spaced approximately 50km apart beginning around Mount Isa and following the trend of the 2007 deep seismic reflection line towards the coast. Sites are buried in inconspicuous locations placed near a low shrub or fence near an access road and and covered with some brush.
35 instruments are operating in the Gulf area at present. The array is being moved east across the state in stages with a small number of overlap sites operating over multiple stages.
The yellow dots on this figure show the approximate locations of the current sites while blue dots indicate the trend of future site positions.
The seismometer is a Lennartz Electronic LE-3Dlite. A compact 10cm cylinder, it contains an active three component
sensor with an eigenfrequency of 1Hz, an upper corner frequency >80Hz and a
dynamic range of 136dB.
The seismometer has an active sensor which draws around 90mW at 12V.
Seismic signals are amplified and combined with GPS timing information before being digitized in an ANU designed short period field recorder.
Data is digitized using a
16bit ADC, usually at 25Hz, and then recorded onto flashcard memory. Data cards are retrieved during each service visit when the batteries are refreshed.
The system is powered by 6 F-cell batteries in series/parallel supplying 12V at installation. With a combined power draw for the seismometer and recorder of around 180mW (15mA), it can record for 3-4 months between battery changes.
