NSW Second Vertical Derivative of TMI RTP (2VD TMI RTP)

Greyscale image of second vertical derivative (2VD) of total magnetic intensity reduced to the pole (TMI RTP). Darker tones indicate lower values and lighter tones represent higher values. Reduction to the pole filters magnetic anomalies to appear as if the Earth's magnetic field were locally vertical, as at the magnetic pole (assuming all magnetic sources are inductively magnetised). The 2VD filter shows the vertical rate of change in the first vertical derivative (1VD) of the Earth's total magnetic field and enhances boundaries and structural detail of shallow sources further than 1VD. The 2VD filter enhances magnetic textures in the image, however, it also amplifies non-geological noise. Variations in the magnetic field are caused by lithological factors, principally magnetite (and/or pyrrhotite) content. This Statewide image was generated by merging many individual airborne magnetic surveys.