.gif)
Victoria University Antarctic Research Expedition Science and Logistics Reports 2001-02: VUWAE 46
Aeromagnetics
Aeromagnetics
A helicopter-borne aeromagnetic survey was carried out over the McMurdo Ice Shelf using an optically pumped Cs-magnetometer housed in a "bird" flown 25 m below the Helicopters New Zealand Bell 212. Survey flights operated from McMurdo Station with an average duration of 3 hours. Navigation was by GPS waypoint and a 500m-spaced E-W line grid was flown at a 300m dropped elevation (Fig. 4). Grid tie lines were flown N-S at the same dropped elevation but with a 2.5 km spacing. Total field and 3 dimensional position was collected on-board and processed against two proton magnetometer base stationed
page 7
positioned on the Pegasus road and behind Black Island, respectively. Standard post processing was applied to all flight lines (repositioning of flight paths, diurnal variation removal, IGRF correction and levelling). The resulting magnetic anomaly data was then gridded by applying a weighted averaging procedure.
.jpg)
Figure 4. Flight line plan for the K114 aeromagnetic survey.
.jpg)
Figure 5. Brute stack of the NHS-1 seismic line.
.jpg)
Figure 6. Brute stack of the NHS-2 seismic line.
.jpg)
Figure 7. Brute stack of the MIS-1 seismic line.
.jpg)
Figure 8. Gravity anomaly map for the McMurdo Ice Shelf gravity surveys with the moat axes and White Island ridge extension indicated.
.jpg)
Figure 9. Magnetic anomaly map from the aeromagnetic survey. Strong red colours indicate large positive magnetic anomalies and strong blue colours indicate large negative magnetic anomalies. Preliminary interpretations are indicated on the figure and in the text.