  The hot QCD matter produced in any heavy ion collision with a nonzero impact
parameter is produced within a strong magnetic field. We study the imprint the
magnetic fields produced in non-central heavy ion collisions leave on the
azimuthal distributions and correlations of the produced charged hadrons. The
magnetic field is time-dependent and the medium is expanding, which leads to
the induction of charged currents due to the combination of Faraday and Hall
effects. We find that these currents result in a charge-dependent directed flow
$v_1$ that is odd in rapidity and odd under charge exchange. It can be detected
by measuring correlations between the directed flow of charged hadrons at
different rapidities, $\langle v_1^\pm (y_1) v_1^\pm (y_2) \rangle$.
