  The interaction between the magnetic field and the elastic deformation field
in the crust is studied in a simplified way. The magnetic fields generated by
the line singularities in a magnetized elastic half-plane are investigated.
Using the general solution and Fourier transform technique, the exact solutions
for the generated magnetic inductions due to various cases are obtained in a
closed form. The results show that the line concentrated force will induced a
perturbed magnetic field; The induced magnetic field will indicate the line
concentrated force in reverse. The distribution of the vertical component of
the magnetic induction caused by the line mechanical singularities is simpler
than that of the horizontal component, and it is zero at the origin when the
applied magnetic field and the line concentrated force satisfies some
conditions. This result is applied to locate the epicenters of the earthquakes
and historical earthquakes occurred in the Chinese continental crust. Results
show that more than 80\% epicenters are at or near the zero-contours of the
vertical component of the magnetic induction observed from satellite. These
regions of zero-contours, especially those in active tectonic zones, could be
the possible seismogenic zones in the future. The zero-contours of the vertical
component of the magnetic induction from satellite could be as geophysical
constraints to the risk information on the shallow seismicities, or they can be
used as an early monitor for the shallow seismicities in the continental crust,
or an auxiliary sign in the determination of the great historical earthquake.
