EFFECTS AND CORRECTION OF TOPOGRAPHY IN MAGNETOTELLURIC SOUNDING
A model with topography was designed.Using the finite difference method,the authors studied the effects of topography on the apparent resistivity and phase curve of MT.Through an analysis and study of distortion curves of simulating models,a number of useful conclusions have been reached.It is shown that the apparent resistivity of TM mode is more easily affected by terrain than that of TE mode,and is more easily distorted at the top than on the bottom of a hill.Meanwhile,theoretical model and real data processing results indicate that the two-dimensional inversion with terrain is very effective and suitable to eliminating the effect of topography on the MT responses.
Abstract A layer of random defects in the simple cubic Ising model with nearest neighbor ferromagnetic interactions of strength J is considered. Using the real space renormalization group method we calculate defect free energy in the whole temperature range. Specifically, we analyze: the layer of diluted defects, the layer of spin-glass type defects, and the layer of mixed defects. The free energy is strongly dependent on the value of couplings between the defect and the bulk.