The geological map units are described in more detail in the accompanying report and expanded legend. Map unit boundaries were interpreted on the basis of the subsurface data airphotos, large-scale topographic maps, and published soil maps. In addition, limited field checking was conducted. In areas of poor subsurface control, the subsurface conditions are largely inferred from topographic and geomorphic evidence. To assist the user in determining the accuracy of the subsurface geological mapping, sites where subsurface geological data were available to us are shown on the maps.
Liquefaction can be one of the major causes of damage during an earthquake.
However, the severity of surface disruption caused by liquefaction is a function of the depth and thickness of the liquefiable units. H i is the layer thickness, and W i is the weighting function that decreases linearly from 0.1 at the surface to 0 at 20 metres. Hazard ratings for specified PLS ranges are summarized in the following table. The larger fills in the Victoria area are associated with port facilities and reclaimed gravel pits. For further details on the hazard assessment of fills, refer to section 5 of the qualifications and limitations of this map.