2-DIMENSIONAL INVERSION OF PAPUA-NEW-GUINEA MAGNETOTELLURIC DATASET ASSUMING STATIC SHIFT AS A GAUSSIAN DISTRIBUTION

The Papua New Guinea Magnetotelluric dataset was analyzed by applying Groom-Bailey tensor decomposition, and a consistent strike direction o f N66 degrees W was determined. The dataset was approximated by two-di mensional impedances, and frequency independent twist and shear. The s tatic shift parameters (local anisotropy and site gain) were determine d using a two-dimensional inversion where static shifts were also part of the model parameters. The model misfit was simultaneously minimize d together with the following two norms: (1) roughness norm of the mod el, and (2) static shift L2 norm. The trade-off parameters between the model misfit and these norms were determined so as to minimize the Ak aike's Bayesian Information Criterion (ABIC).