Table 1 Summary of parameters used during 2-D resistivity inversions (modified after Martorana et al. 2009 )

Initial damping factor

Minimum damping factor

Convergence limit

Minimum change in absolute error

Number of iterations

Jacobian matrix is recalculated for first two iterations

Increase of damping factor with depth

Robust data inversion constrain is used with cut off factor

Robust model inversion constrain is used with cut-off factor

Extended model is used

Effect of side blocks is not reduced

Normal mesh is used

Finite difference method is used

Number of nodes between adjacent electrodes

Logarithm of apparent resistivity used

Reference resistivity used is the average of minimum and maximum values

Gauss - Newton optimization method