For decades, scientists have known that extreme solar storms, or coronal mass eruptions, can cause severe damage to electrical grids and even blackouts. The effects would be felt all over the world, from transportation and global supply chains to internet and GPS access. The potential impact of such a solar emission on the internet infrastructure has been less studied. New research has shown that such a solar emission could have a catastrophic effect on the internet infrastructure. Abdu Jyothi’s research reveals an additional nuance to a solar storm that causes blackouts. This is the scenario in which even if power comes back within hours or days, widespread internet outages continue. There’s good news. Abdu Jyothi discovered that the local and regional internet infrastructure is not at risk even in a large solar storm. This is because optical fiber itself doesn’t get affected by geomagnetically-induced currents. Also, short cable spans are grounded regularly. The risks for long undersea cables connecting continents are greater. A solar storm could disrupt many of these cables, cutting off connectivity to countries at the source. However, it would not affect local infrastructure. It would be similar to cutting off water flow to an apartment because of a water main breaking. “What really got my attention was that we saw how unprepared the entire world was during the pandemic. Before her talk, Abdu Jyothi explained that there was no protocol in place to effectively deal with the pandemic. “Our infrastructure is not ready for large-scale solar events. We don’t know the extent of the damage. This is mostly due to a lack of data. Because severe solar storms are rare, there are only three examples in recent history of such an event. Large events such as the 1859 and 1921 “Carrington Events” demonstrated how geomagnetic disturbances can cause disruptions to electrical infrastructure and communication lines, like telegraph wires. The massive 1859 “Carrington Event” saw compass needles swing wildly and unpredictably at the equator of Colombia. These geomagnetic storms happened before modern electric grids were built. A moderate-severity sunspot in 1989 knocked out Hydro-Quebec’s grid. It also caused a nine-hour blackout across northeast Canada. However, this too happened before the advent of modern internet infrastructure. Abdu Jyothi says coronal mass ejections pose a serious threat to internet resilience even though they are not common. After three decades of low solar storm activity she and other researchers point to the fact that there is a greater chance of another incident. Below-sea internet cables can be vulnerable to solar storm damage for several reasons. Cables are equipped with repeaters that can be used to transmit data across oceans. Repeaters are placed at intervals of approximately 50 to 150 kilometers, depending on the cable. These repeaters amplify the optical signal and ensure that nothing is lost during transit. This is similar to a relay throw in baseball. Although fiber optic cable is not directly susceptible to disruption by geomagnetically-induced currents, repeater’s electronic internals are. Repeater failures can render entire undersea cables inoperable. Undersea cables are not grounded at long intervals hundreds to thousands of kilometers apart, leaving vulnerable components such as repeaters more susceptible to geomagnetically induced currents. There are also differences in the composition of the seafloor, which could make some grounding points more efficient than others.