A Carrington-class solar storm could disable global internet connectivity and power grids for months by inducing direct currents into long-distance conductors. According to UC Irvine computer scientist Sangeetha Abdu Jyothi, such an event could knock out undersea cables by damaging the copper power lines that feed signal repeaters, requiring months of ship-based repairs.
Why do geomagnetic storms crash power grids?
Solar storms do not directly electrocute people; instead, they “electrocute” the electrical grid. When a coronal mass ejection hits Earth’s magnetic field, it creates a rapidly changing magnetic field that induces an electric field in any conductor. This process, based on the principles of Michael Faraday, generates geomagnetically induced currents (GIC).
These GICs are direct currents (DC) that enter the power network through grounding rods at substations. While power grids are designed for symmetrical alternating current (AC), these slow, heavy DC flows saturate a transformer’s magnetic core. This saturation causes the equipment to heat up, vibrate, and bleed harmonics into the network.
The March 13, 1989, event in Quebec provides a historical precedent. A solar storm slammed into the Earth’s magnetic field, causing seven static-VAR compensators to trip offline in succession. This loss of voltage support collapsed the Hydro-Québec grid, leaving six million people without power for nine hours.
How does solar weather threaten undersea internet cables?
While fiber-optic strands are made of glass and are unaffected by magnetism, the infrastructure supporting them is highly vulnerable. Submarine cables contain a copper or aluminum conductor that delivers thousands of volts of DC to repeaters every 50 to 100 kilometers to amplify light pulses.
Because these cables are long, grounded conductors, they are primary targets for GICs. In her 2021 paper, Solar Superstorms: Planning for an Internet Apocalypse, Abdu Jyothi concluded that while local city fiber might survive, the long-haul links between continents could face months of downtime while repeaters are inspected and replaced by specialized ships.
Comparing 1859 to the Modern Era
The scale of vulnerability has changed significantly since the benchmark Carrington Event of September 1859. During that event, telegraph operators reported sparks leaping from equipment, yet they were still able to send messages using the current pushed through the wires by the storm. Today, the “long metal” has expanded from telegraph wires to high-voltage transmission lines, steel-skinned gas pipelines, and the copper power-feeds in undersea cables.
Which geographic regions face the highest risk?
The impact of a geomagnetic storm is determined by both solar intensity and local geology. The induced electric field is strongest in auroral latitudes and in areas where the ground is highly resistive. Ancient cratonic rock, such as the Canadian Shield, the Scandinavian Baltic Shield, and the bedrock under New Zealand’s South Island, prevents induced currents from sinking easily into the dirt.
Instead of entering the ground, the current travels through man-made metal conductors. This explains why the 1989 storm caused a total collapse in Quebec while New York, situated on younger and wetter geology, remained largely unaffected. Similarly, South Africa’s Eskom experienced long-term damage to large transformers during the October 2003 Halloween storms, as the equipment “cooked” from the inside due to GIC-induced degradation.
Can space agencies provide enough warning?
Current warning times are limited by the distance between the Sun and Earth. While light from a solar flare reaches Earth in eight minutes, the plasma cloud responsible for GICs takes between 15 hours and three days to arrive.
The NOAA Space Weather Prediction Center and the ESA utilize spacecraft like DSCOVR and ACE, parked at the L1 Lagrange point, to provide a final warning. These sensors sit roughly 1.5 million kilometers upstream, offering roughly 15 to 60 minutes of notice before the plasma cloud hits the magnetosphere. While this window is sufficient for grid operators to adjust loads or for airlines to reroute polar flights, it is not enough time to “harden” infrastructure that is not already prepared.
Future Mitigation Trends
- Satellite Constellations: Proposals like the StormWall constellation aim to place observation tools closer to the Sun to extend warning times to several hours.
- Grid Instrumentation: Operators like New Zealand’s Transpower are increasingly using magnetometers and running storm-response drills to prepare for sudden GIC flows.
- Infrastructure Hardening: Engineering focus is shifting toward protecting the insulation of custom-built transformers, which can take 12 to 18 months to manufacture if destroyed.
Frequently Asked Questions
Will a solar storm electrocute me?
No. A geomagnetic storm affects the electrical grid and long conductors, not the human body directly.
How long does it take to replace a damaged power transformer?
Large, custom-built transformers can take between 12 and 18 months to manufacture and install.
Does the internet go down during a solar storm?
Local fiber-optic networks are likely to survive, but the undersea cables that connect continents are at high risk of damage to their power-delivery systems.
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