Geoelectric Strike Analysis from Magnetotelluric (MT) Data Using Swift and Polar Diagram Methods

2nd Southeast Asian Conference on Geophysics

Maulinadya, S.^1 ; Grandis, H.^1

Faculty of Mining and Petroleum Engineering, Institut Teknologi Bandung (ITB), Jalan Ganesha 10, Bandung

40132, Indonesia^1

关键词: 2D modelling;    Computational resources;    Conductivity structures;    Geoelectrical;    Impedance tensor;    Polar diagrams;    Regional geology;    Rotational analysis;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/318/1/012049/pdf
DOI  :  10.1088/1755-1315/318/1/012049

来源: IOP

【 摘 要 】

The magnetotelluric (MT) method is commonly used to estimate the subsurface conductivity structure. From the point of view of computational resources availability, currently it is a common practice to perform a 2D MT inversion modelling of MT data measured along a profile. For that purpose, the geoelectric strike angle determination from MT data is essential. The geoelectric strike angle can be determined by rotational analysis of the MT impedance tensor. In this paper we compare geoelectrical strike angle from both Swift method and polar diagram analysis by plotting the results as rose diagrams. The results from rotational analysis suffer from 90° ambiguity in the structural direction. Along with information from the regional geology to resolve the ambiguity, the profile for MT 2D modelling can be more appropriately selected. We used MT data from a geothermal prospect to illustrate our exercise.