As our dependence on electricity and technology grows, so does our vulnerability to space weather. Most people are aware of threats to power grids from cyber and physical attacks and major storms, but less known is the havoc the sun can create. A solar geomagnetic storm is capable of collapsing our power grid. 

In the Summer of 1859, solar astronomer Richard Carrington witnessed a solar flare in broad daylight from his observatory outside of London, which he described as “two patches of intensely bright light and white light.” 

Early the next morning, the impact of these massive solar flares was felt around the world. Telegraph communications globally began to fail. Fires ignited from sparks generated by the burst of energy travelling down the lines, and auroras (northern and southern lights) set the sky aflame with a red glow seen as far south as Colombia. According to historian Christopher Klein, this extreme geomagnetic storm, called the “Carrington Event” is the largest storm on record, striking the Earth with the energy of 10 billion atomic bombs. 

Magnetic storms are the atmospheric effects felt on Earth from events occurring on the sun. They begin when the sun emits bursts of energy called solar flares that are as powerful as billions of nuclear bombs. These are usually followed by the release of charged plasma streams that travel at millions of miles per hour, called coronal mass ejections or CMEs. Depending on the size of the CME and direction it is headed, if it hits Earth, it can cause geomagnetic storms that may disable, damage or interrupt power and internet systems, and more. A scenario of a “Carrington-Event” occurring today estimates the impact on the U.S. economy could reach trillions of dollars. 

If an extreme geomagnetic storm like the Carrington Event were to happen now, the National Weather Service (NWS)’s Space Weather Prediction Center says widespread problems could occur. The power grid could completely collapse or experience blackouts. Satellites, GPS and other navigational systems could suffer extensive damage or disruption, lasting for hours, days, weeks or even months. The NWS Space Weather and Safety site lists cascading effects from significant power outages: we could lose water and wastewater systems, perishable foods and medications, heating, air conditioning and lights, computer systems, telephone systems, satellite networks and GPS service, public transportation systems, fuel distribution systems, and all electrical systems without backup. 

The frequency of solar flares follows an 11-year cycle. The risk of intense geomagnetic storms is elevated during the peak, or midpoint of the solar cycle. At peak activity, there could be several solar storms each day. At other times, there might be less than one solar storm per week. The current cycle is expected to peak during 2024-2025. 

A large CME struck Earth in March 1989, knocking out power grids in Quebec, Canada and causing significant interference to power systems in the Eastern United States. A high-voltage transformer at a nuclear power plant even melted due to the overload of electricity in the grid. This was a wake-up call for infrastructure leaders and power companies, who began building safety measures into the electrical grid to stop cascading failure and set aside spare transformers for emergency use. 

Both the Obama and Trump administrations issued orders for Federal Government agencies to work together on space weather study, assessment, and prediction. In 2019, the White House’s National Science and Technology Council released a National Space Weather Strategy and Action Plan, and in 2020, Congress passed the Promoting Research and Observations of Space Weather to improve the ‘Forecasting of Tomorrow’ Act. 

In 2019, the U.S. Geological Survey (USGS) studied how electric power grid operators across the north and central United States would be affected by a once-per-century magnetic superstorm. Dr. Jeffrey Love, a research geophysicist with USGS, told the PRT that this work demonstrated that large areas of the nation that have relatively electrically resistive rock would experience higher magnetic storm hazards than locations where the rock material is a good conductor of electricity, where the current flows easily through the ground. 

If the rock is electrically resistive (including igneous and metamorphic formations), high-voltage electric wires will be more susceptible to magnetic storm induced electricity, forming a larger threat to the grid. 

Love and his colleagues found that large portion of the eastern seaboard from North Carolina, through Virginia, Pennsylvania, New York and up to Maine – as well as a portion of Minnesota, North Dakota, and Wisconsin – sit above high-risk geologic rock structures. 

“These results… tell us where we need to concentrate our efforts,” said Love. “The seats of government, the financial industry and many people live in these higher risk areas. Special scrutiny in those areas is needed to ensure the resilience of power grid systems against magnetic storms.” 

Love said Arizona and the remaining southern states should be mapped in the next couple of years. At this point in time, there is no hard data to determine how electrically resistive the rock structure in Arizona is.

While USGS is leading the effort to assess geoelectric hazards to the power grid, many other government agencies and academic institutions are involved in studying space weather. The National Oceanic and Atmospheric Administration (NOAA) monitors real-time response of the earth to space weather. The National Science Foundation and NASA support research. The Department of Energy and Federal Energy Regulatory Commission ensure the electrical power industry is responsive to hazards. The Department of Defense is working to protect their systems. Homeland Security/FEMA is planning and preparing for the aftereffects of a storm. 

“The work I do and some of my colleagues is coordinated out of an office in the White House and that has brought significant progress to this subject,” said Love. 

Love said that intense magnetic storms do not happen very often, but when they do, the implications can be very widespread. He added that over the last 20 years of his involvement, significant progress has been made with government, industry, and academia taking the storm threat seriously. 

Jack Blair, vice president of Member Services at Sulphur Springs Valley Electric Cooperative, said most outages on the system are storms with high winds, fires, vehicle accidents and animals and birds, where power can be rerouted quickly. 

“For solar storms and geomagnetic storms and electromagnetic pulses (EMP) we have safety equipment on our lines that minimize damage,” he said. “We are often contacted about the Carrington Storm from 1859 that caused all the telegraph systems in the area to fail. The key thing to remember is there was no safety equipment in place in those days. Today we have numerous safety devices that protect our system.” 

Love encourages people to be interested in science and challenge their curiosities whether it’s space weather, astronomy, geology, or meteorology. Although he said he would not advise people to go out and buy a generator, he does encourage people to expect their government to pay attention to science and to be responsive to the natural hazards that scientists understand are real. 

As a major voice in the worldwide geophysical community, Love warns that the geoelectric “perfect storms” will happen; it’s not a question of if, but when. 

For additional information visit to sign up for Space Weather Alerts and receive a text message when magnetic storms erupt. 

Editor’s note: Look for “Space Weather – Part 2” in the October issue of the PRT.