DIMENSIONALITY AND DIRECTIONALITY ANALYSIS OF MT IMPEDANCE TENSOR

Abstract

in Magnetotellurics, the observed impedance tensor contains a lot of information like dimensionality and directionality of the subsurface which can be extracted. Since in general case. Earth subsurface is 3D in nature and 31) problems are very difficult to solve br human as well as for machines while on the other hand MT is able to delineate whether subsurface can be approximated to 2D or II) without enormous processing on the basis of dimensionality analysis. so dimensionality analysis of MT impedance tensor can help us a great deal in reducing the processing time and computation which save the energy. most importantly time and money. The purpose ol this dissertation is to develop MATI.A13 code that helps us in anal sing the dimensionality and directional it) of' MT impedance tensor using WAL Invariants method. The code is validated on synthetic data which is generated using 31) modelling br Mi data module of' WinGLink software. When the results of s)ntlietic model, given in paper. Weiver et al. 2000, matches with published one then code is applied on the MT data along the Roorkee- Gangotri profile acquired by Israil et al.. 2008. The results of dimensionality and directionality produced by code for WAL. Invariants method is compared with that ot 13ahr decomposition method. 'Groom Bailey decomposition method'. 'Phasor tensor method'. 'Lilly decomposition method' on synthetic as well as real data. All methods are found to produce same results in ideal conditions. The codes for these other methods were developed by dissertation students in 2013 under supervision of Prof Pravin K. Gupta and Prof M. Israil.