On September 1 and 2, 1859, telegraph systems around the world failed catastrophically. Telegraph operators reported experiencing electric shocks, telegraph paper catching fire, and being able to operate equipment with disconnected batteries. During the evening, the aurora borealis, more commonly known as the northern lights, could be seen as far south as Colombia. Typically, these lights are only visible at higher latitudes, in northern Canada, Scandinavia and Siberia.
What the world experienced that day was a massive geomagnetic storm, now known as the Carrington Event. These storms occur when a large bubble of superheated gas called plasma is released from the surface of the sun and hits the Earth. This bubble is called a coronal mass ejection.
The plasma of a coronal mass ejection consists of a cloud of protons and electrons, which are electrically charged particles. When these particles reach Earth, they interact with the magnetic field around the planet. This interaction distorts and weakens the magnetic field, causing the strange behavior of the aurora borealis and other natural phenomena. As an electrical engineer specializing in the power grid, I study how geomagnetic storms are prone to cause power and internet outages and how to protect against them.
Geomagnetic storms
The Carrington Event of 1859 is the largest recorded account of a geomagnetic storm, but it is not an isolated event.
Geomagnetic storms have been recorded since the early 19th century, and scientific data from Antarctic ice core samples has shown evidence of an even larger geomagnetic storm that occurred around AD 774, now known as the Miyake Event. That solar flare created the largest and fastest increase in carbon-14 ever recorded. Geomagnetic storms trigger high amounts of cosmic rays in Earth’s upper atmosphere, which produce carbon-14, a radioactive isotope of carbon.
A geomagnetic storm 60% smaller than the Miyake Event occurred around AD 993. Ice core samples have shown evidence that large-scale geomagnetic storms with intensities similar to the Miyake and Carrington events occur at an average rate of once every 500 years.
Today the National Oceanic and Atmospheric Administration uses the Geomagnetic Storms scale to measure the strength of these solar flares. The “G scale” is rated from 1 to 5 with G1 being mild and G5 being extreme. The Carrington Event would have a G5 rating.
It becomes even scarier when you compare the Carrington Event to the Miyake Event. The scientist was able to estimate the strength of the Carrington Event based on the fluctuations in the Earth’s magnetic field as recorded by observatories at the time. There was no way to measure the magnetic fluctuation of the Miyake event. Instead, the scientists measured the increase in carbon-14 in tree rings from that time period. Carbon-14 increased by 12% with Miyake’s departure. In comparison, the Carrington Event increased Carbon-14 by less than 1%, so the Miyake Event probably had a significant effect on the G5 Carrington Event.
Knock out power
Today, a geomagnetic storm of the same intensity as the Carrington Event would have a far greater impact on telegraph wires and could be catastrophic. With ever-increasing dependence on electricity and emerging technology, any disruption could result in trillions of dollars in monetary loss and risk to life depending on the systems. The storm would affect the majority of electrical systems that people use every day.
Geomagnetic storms generate induced currents, which flow through the electrical grid. The induced geomagnetic currents, which can exceed 100 amperes, flow into the electrical components connected to the grid, such as transformers, relays and sensors. One hundred amperes is equivalent to the electrical service provided to many households. Currents of this magnitude can cause internal damage to the components, causing large-scale power outages.
A geomagnetic storm three times smaller than the Carrington Event occurred in Quebec, Canada, in March 1989. The storm knocked out the Hydro-Québec electrical grid. During the storm, the high magnetic induction currents damaged a transformer in New Jersey and tripped the grid’s circuit breakers. In this case, five million people were without power for nine hours due to the outage.
Connection broken
In addition to electrical failures, communications would be disrupted on a global scale. Internet service providers could go out of business, taking away the ability of different systems to communicate with each other. High frequency communication systems such as ground-to-air radio, shortwave and ship-to-shore radio would be disrupted. Earth-orbiting satellites could be damaged by induced currents from the geomagnetic storm igniting their circuit boards. This would affect satellite telephone, internet, radio and television.
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Also, as geomagnetic storms hit the Earth, increased solar activity causes the atmosphere to expand. This expansion changes the density of the atmosphere in which satellites orbit. A high-density atmosphere creates a drag on a satellite, which slows it down. And if it is not moved to a higher orbit, it may fall back to Earth.
Another area of interference that can affect everyday life is navigation systems. Almost all modes of transportation, from cars to airplanes, use GPS for navigation and tracking. Even handheld devices such as mobile phones, smart watches and tracking tags rely on GPS signals sent from satellites. Military systems rely heavily on GPS to coordinate. Other military detection systems such as over-the-horizon radar and submarine detection systems could be affected, thereby affecting national defence.