You might want to do a little more research and be certain you understand how the pulses can interact WITHIN the earth itself – not just radiating through the atmosphere. Grounding by itself is not a cure-all.
EMP (electromagnetic pulse) can be caused by an high-altitude nuclear weapon that will interact with the Earth’s atmosphere, ionosphere, and magnetic field to produce an EMP radiating down to the Earth and create electrical currents in the Earth.
Sorry – I don’t have the time to do all the research, but I have previously seen multiple articles that detail how, depending on the circumstances of the EMP, the earth itself is a conduit for much of the damage. It isn’t just line of sight above ground.