  This paper is a continuation and an extension of our recent work [13] on the
identification of magnetized anomalies using geomagnetic monitoring, which aims
to establish a rigorous mathematical theory for the geomagnetic detection
technology. Suppose a collection of magnetized anomalies is presented in the
shell of the Earth. By monitoring the variation of the magnetic field of the
Earth due to the presence of the anomalies, we establish sufficient conditions
for the unique recovery of those unknown anomalies. In [13], the geomagnetic
model was described by a linear Maxwell system. In this paper, we consider a
much more sophisticated and complicated magnetohydrodynamic model, which stems
from the widely accepted dynamo theory of geomagnetics.
