Joint EM/MT inversion (JEM)
Magneto-telluric data are sensitive to different properties of the earth than CSEM; as a generalisation, they are sensitive to the macro background structure and relatively insensitive to thin layers.
Although lacking the resolution of CSEM it can be particularly valuable in penetrating deeper into the section and providing information on the basement.
Jointly inverting CSEM and MT data can have a number of valuable outcomes:
the MT data can serve to provide background measurements for the EM data, in flood basalt and salt provinces, seismic surveys can often provide only limited information below the top of these bodies.
A combination of CSEM and Magneto Telluric techniques provides a powerful way to image this region: CSEM data are primarily sensitive to the salt/basalt and region above the salt/basalt, whilst the MT data are sensitive to conductive underlying sediments and any resistive basement which may be present.
This joint inversion module deals with the complex relationship between the CSEM and MT measurements of the earth’s resistive structure. The code can deal with anisotropic differences between vertical resistivity (mainly sensed by CSEM) and horizontal resistivity (mainly sensed by MT).
All of OHM’s INV2D products may be used with Joint EM (JEM) datasets.
Data can be output as a graphic image, or on various electronic formats including SEG-Y