Abstract:

Occam’s inversion is reliable and  able to incorporate varying levels of the priori information. The Choice of Lagrange multiplier is computationally expensive and some direct selection methods are then suggested in this paper.  We modified the selected method of Lagrange multiplier in 2D magnetotelluric Occam’s inversion. In the search progress, the misfit between  the forward model response and  observed data are added and compared with  the  target level. This can eliminate superfluous forward calculation in the last iteration of the phase of bringinge misfit down and the phase of smoothing out the unnecessary structure. This modification  can accelerate inversion and more accordant with   the Occam’s idea.Through inversions of several synthetic and field data,it is improved that forward caculation number can be reduced to 20%-50%.

Key words: Occam’s inversion, Lagrange multiplier, smoothest model, magnetotellurics (MT)