  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 that
these fields 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 v1 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, $\langle
v_1^\pm(y_1)v_1^\pm(y_2)\rangle$.
