The gravity waves (GWs) produced by potential vorticity (PV) anomalies in a vertical wind shear are evaluated for an unbounded rotating stratified flow. In this set-up, the disturbances have two inertial layers, one on each side of the PV anomaly that produces them. Between these layers the disturbance is well predicted by the quasi-geostrophic theory, beyond these layers it corresponds to propagating GWs.