Scientists have known for decades that an extreme solar storm could damage power grids and potentially cause prolonged blackouts. The repercussions would be felt everywhere, from global supply chains and transportation to GPS.
Less examined so far, however, is the impact such solar emission could have on the Internet infrastructure in particular. New research shows that the failures could be catastrophic - a veritable apocalypse, in the true meaning of the term, particularly for the undersea cables that underpin the global internet.
Sangeetha Abdu Jyothi, researcher at the University of California, has just presented a study, “Solar Storms: Planning an Internet Apocalypse”. This is an examination of the damage that a cloud of fast-moving magnetized solar particles could cause to the world grid. Abdu Jyothi's research highlights a scenario that has been little considered until now: one in which, even if the energy returns in a few hours or days, after a similar storm, Internet outages would persist.

Internet apocalypse
Let me start by saying that there is good news. Abdu Jyothi found that local and regional Internet infrastructure would be at low risk of damage even in a massive solar storm, because the optical fiber is not affected by geomagnetically induced currents. The problem would be for the long submarine cables linking the continents, though. A solar storm affecting a number of these cables around the world could cause a massive loss of connectivity by cutting countries at their source, even leaving local infrastructure intact. Hence the definition of "Internet Apocalypse" used with knowledge by the researcher.
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 the resilience of the internet. Our infrastructure is not prepared for a large-scale solar event. We have a very limited understanding of what the extent of the damage would be.
Sangeetha Abdu Jyothi, University of California
This information gap mainly stems from a lack of data
Severe solar storms are so rare that we only have them three main examples throughout recent history. Major events in the 1859 and in 1921 have shown that geomagnetic disturbances can disrupt electrical infrastructure and communication lines such as telegraph wires. In 1859, the compass needles swung wildly, and the Northern Lights were visible at the equator in Colombia. But those geomagnetic disturbances occurred before modern power grids were established. A solar storm of moderate severity in 1989 caused a nine-hour blackout in northeastern Canada, but no "internet apocalypse" - this too occurred before the rise of modern web infrastructure.
While they don't happen often, coronal mass expulsions are a real threat to the resilience of the internet, says Abdu Jyothi. And after three decades of low solar storm activity, the likelihood of another crash is increasing.
Why are underwater cables at risk?
To keep data across oceans intact, the cables are equipped with repeaters at intervals of about 50-150 kilometers depending on the cable. These devices amplify the optical signal, making sure that nothing is lost in transit, like a relay thrown in baseball. These repeaters are the "weak link" in the chain when exposed to geomagnetic currents. However, the "internet apocalypse" would also affect any equipment orbiting the earth. Bad news for Starlink, eg.
But exactly, how much damage and where would it occur? "There are no models currently available on how this could go," says Abdu Jyothi. “We are more aware of how these storms would impact energy systems on the ground. In the ocean it is difficult to predict. "
Coronal mass ejections tend to have a greater impact at higher latitudes, closer to the Earth's magnetic poles. That's why cables in some regions would be more interested in the internet apocalypse than others. Asia would take less risk, because Singapore serves as a hub for many undersea cables in the region and is at the equator. For the cables that cross the Atlantic and Pacific oceans, however, it would probably be a disaster even in the case of solar storms that are not very serious.

The risk? Not an apocalypse, but a half palingenesis yes.
The internet is structurally resilient: if a route is not available, traffic diverts to other routes. This is a property that could potentially maintain connectivity, even at slow speeds, in the event of a solar storm. But enough damage to these vital arteries would begin to destabilize the network. And depending on where the cable breaks occur, Abdu Jyothi says fundamental data routing systems like the Domain Name System may start to malfunction, creating chain breaks.
What do I think of it? There are some people who think that a geomagnetic disturbance would be a catastrophic scenario and there are others who think it would be less of a major event. I am a little bit in the middle. I think the prospect of an "Internet Apocalypse" is something the industry certainly needs to be prepared for.