P903tmivd1g

Total magnetic intensity (TMI) data measures variations in the intensity of the Earth's magnetic field caused by the contrasting content of rock-forming minerals in the Earth crust. Magnetic anomalies can be either positive (field stronger than normal) or negative (field weaker) depending on the susceptibility of the rock. The data are processed via standard methods to ensure the response recorded is that due only to the rocks in the ground. The results produce datasets that can be interpreted to reveal the geological structure of the sub-surface. The processed data is checked for quality by GA geophysicists to ensure that the final data released by GA are fit-for-purpose.This P903tmivd1g is a first vertical derivative of the Total Magnetic Intensity grid for the SMMSP - AEM - Honeysuckle Creek, Vic, 2001.This grid has a cell size of 0.00042 degrees (approximately 42m). The grid has units of nanoTesla per km (or nT/km). The data used to produce the TMI grid was acquired in 2001 by the VIC Government, and consisted of 6082 line-kilometres of data at 200m line spacing and 115m terrain clearance. A Fast Fourier Transform (FFT) process was applied to the original grid to calculate the first vertical derivative grid.