3D MODELLING MAGNETOTELLURIC DATA USING ModEM : CASE STUDI CASCADIA SUBDUCTION ZONE

• Main Author: ASMORO (NIM : 20216038), LANGGENG
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/28551
• Institution: Institut Teknologi Bandung

Magnetotelluric method (MT) is one of geophysical method which use electromagnetic wave to identify conductive materials in subsurface. One of the application from this method is geothermal system identification. Data is formed from electric field and magnetic field than processed to get impedance value. The value of impedance is used in inversion processes to get the distribution of resistivity. magnetotelluric inversion is usually done in 2 dimension profile. 2 dimension inversion is choosen because it fast and easy to use. But, the result from 2 dimension inversion contain more ambiguity than the result from 3 dimension inversion. It’s very important to do 3 dimension inversion to get better distribution of resistivity. <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> In this study has been done of 2 dimension and 3 dimension inversion processes. Magnetotelluric data use syntetic data and real data. The result from inversion processes is subsurface resistivity in 2 dimension and 3 dimension than compare the result. Inversion result from real data is the resistivity distribution to indentifiy subduction zone of Cascaia. Inversion is done using ModEM, software from Anna Kelbert and gery Egbert since 2012 than compared with other inversion method. The 3D inversion result has better result than 2D inversion. Conductivity distribution show the subnduction zone of Cascadia. Then, Inversion performa from ModEM is better than comparing method WS3DINV. <br />