Document Title - Geoscience Australia

Lord Howe High Resolution Grids
Lord Howe Island and Ball’s Pyramid Plateau 100 metre grid
The higher resolution grid is shown in Figure 28. This grid focuses on the flanks of the volcano
which show considerable detail. At this resolution not much detail is seen on the plateau. This grid
may not match up perfectly at the edges with the 250 m grid as it used a subset of the data shown in
Figure 25, using mainly the swath data from the base of the plateau inward as well as the LADS,
satellite derived bathymetry, chart and topographic data in the shallow water. The computational
parameters used in Intrepid are shown in the table.
Table 5: Intrepid gridding parameters for the ~100 m grid.
PARAMETER
VALUE
Latitude range
-32.2 o to -31.12 o
Longitude range
158.62 o to 159.7 o
Cell size
0.0009 degrees ( ~3 sec of arc)
Cell assignment
Nearest neighbour
Minimum curvature tension 0.5
Maximum iterations 2,000
Maximum residual
0.01 m
Extrapolation limit
1,000 cells
31.12 o S
159.7 o E
32.2 o S
158.62 o E
Depth in metres
Figure 28: The Lord Howe volcano base 100 m grid showing the fine detail in the flanks
(vertical exaggeration X 4, position marker approximate only).
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