At the SIGCOMM 2021 data communication conference on Thursday, Sangeetha Abdu Jyothi of the University of California, Irvine presented “Solar Superstorms: Planning for an Internet Apocalypse,” an examination of the damage a fast-moving cloud of magnetized solar particles could cause the global Internet. Abdu Jyothi’s research points out an additional nuance to a blackout-causing solar storm: the scenario where even if power returns in hours or days, mass Internet outages persist.

There’s some good news upfront. Abdu Jyothi found that local and regional Internet infrastructure would be at low risk of damage even in a massive solar storm, because optical fiber itself isn’t affected by geomagnetically induced currents. Short cable spans are also grounded very regularly. But for long undersea cables that connect continents, the risks are much greater. A solar storm that disrupted a number of these cables around the world could cause a massive loss of connectivity by cutting countries off at the source, even while leaving local infrastructure intact. It would be like cutting flow to an apartment building because of a water main break.

“What really got me thinking about this is that with the pandemic we saw how unprepared the world was. There was no protocol to deal with it effectively and it’s the same with Internet resilience,” Abdu Jyothi told WIRED ahead of her talk. “Our infrastructure is not prepared for a large-scale solar event. We have very limited understanding of what the extent of the damage would be.”