Letter Re: EMP

Hi Jim,

Do you know if we have a EMP attack or if the grid goes down weather we will still have internet service? – GLB

HJL Replies: Since the vast majority of the Internet depends upon the power grid, it really depends on how much of the power grid survives an EMP event. The long hauls of the infrastructure would probably survive due to the fact that most are based on fiber optics, which are not affected by EMP. The hubs, connection points and routers all have to have power though, which is affected by EMP events. If the locations are sufficiently hardened, they may survive. If they are not EMP hardened, they most likely will not survive. I suspect that we would have isolated pockets that would be just fine and most long hauls would be fine as well. The connectivity of the Internet would greatly depend on those areas that are powered by commercial electric power or have sufficient metal wiring to be able to induce EMP spikes large enough to kill electronic equipment with minimal protection. The Internet was designed to be a self healing network (or at least able to route around isolated problems) so if enough infrastructure survives, it may indeed be useful. However, I suspect that it will not be very usable though since the usability is directly related to connectivity.