Joint inversion may reduce the ambiguities in geophysical inversion problems. It can be applied to multi-attributes or multi-physics to study subsurface geophysical properties. Examples of multi-attributes include joint P-wave velocity and S-wave velocity inversion, joint velocity and attenuation inversion. Joint electromagnetic and seismic inversion is an example of multi-physics inversion. Above is a diagram of joint inversion with multi-geophysical data.
Zhu, T., and Harris, J., Interative joint inversion of P-wave and S-wave crosswell traveltime data, Extended Abstract submitted to SEG Annual Meeting.