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Earth barely missed a solar superstorm of devastating magnitude on 23 July 2012, according to a new study reported in the journal Nature Communications.

A rapid succession of coronal mass ejections crossed the Earth’s orbit on that day. If the eruptions had occurred nine days earlier, the result would have rivaled the Carrington Event of 1859, the most intense geomagnetic storm ever recorded, according to a team led by Professor Ying Liu of the State Key Laboratory of Space Weather, China and UC Berkeley research physicist Dr. Janet Luhmann.

“Had it hit Earth, it probably would have been like the big one in 1859, but the effect today, with our modern technologies, would have been tremendous,” said Luhmann, who is part of the NASA STEREO (Solar Terrestrial Relations Observatory) team and based at UC Berkeley’s Space Sciences Laboratory. The coronal mass ejections were detected by the STEREO A satellite.

During the Carrington event, the telegraph system (which was the dominant form of communication at the time) was knocked out across the United States, and the Northern Lights lit up the night sky as far south as Hawaii. A much smaller event in 1989 knocked out Canada’s Hydro-Quebec power grid and resulted in the loss of electricity to six million people for up to nine hours.

If a Carrington-level event hit North America today, damage is estimated at $0.6-2.6 trillion, according to a 2013 report by Lloyd’s and Atmospheric and Environmental Research, Inc. Damage to electrical transformers would leave 20-40 million Americans without power, some for as little as 16 days, some for as long as 1-2 years. (Another study, commissioned by Oak Ridge National Laboratories, estimates that power outages would affect 70% of the US population.) The lead time for building new transformers is a minimum of five months.

According to Lloyd’s, the most vulnerable area in the US is the Atlantic corridor between Washington DC and New York City. (This takes into account magnetic latitude, distance from the coast, ground conductivity, and the condition of the local power.) The Midwestern states and Gulf Coast are also high-vulnerability areas.

Long-term blackouts would mean loss of other services. Traffic lights, communications; agriculture and food distribution; municipal water and sanitation; fire, police, and medical services; banking; even local gas pumps — all depend on electricity.

Electrical power would not be the only energy source affected by a geomagnetic storm. Oil and gas pipelines are also vulnerable. So are satellites, railroads, telephone lines, and even undersea cables.

Heart attacks and strokes have been shown to increase dramatically during geomagnetic storms, but the most significant health risk would be from the loss of infrastructure. Cumulative death tolls could be in the millions.

Liu, Luhmann, and their STEREO colleagues conclude that the that the 2012 event propelled material outward at a peak speed of more than 2,000 kilometers per second, four times the speed of a typical eruption. Fortunately, the Earth was not in the line of fire at the time. The sun rotates every 25 days at the equator, so nine days earlier the ignition spot would have been pointed directly at Earth.

The researchers determined that the huge outburst resulted from at least two, nearly simultaneous coronal mass ejections. Each coronal mass ejection typically releases an energy equivalent to about a billion hydrogen bombs. The speed was so high, they conclude, because of another mass ejection four days earlier, which cleared the path for the later eruptions.

“The authors believe this extreme event was due to the interaction of two CMEs separated by only 10 to 15 minutes,” said Joe Gurman, the project scientist for STEREO at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

Another factor which made this event potentially dangerous was its very long-duration, south-oriented magnetic field, Luhmann said. This orientation drives the largest magnetic storms when they hit Earth. The southward field merges violently with Earth’s northward field in a process called reconnection. Instead of dumping their energy only at the poles, such storms dump it into the radiation belts, ionosphere, and upper atmosphere, creating auroras all the way down to the tropics.

“People keep saying that these are rare natural hazards, but they are happening in the solar system even though we don’t always see them,” Luhmann said. “It’s like with earthquakes — it is hard to impress upon people the importance of preparing unless you suffer a magnitude 9 earthquake.”

“Observations of solar superstorms have been extremely lacking and limited, and our current understanding of solar superstorms is very poor,” Liu said. “Questions fundamental to solar physics and space weather, such as how extreme events form and evolve and how severe it can be at the Earth, are not addressed because of the extreme lack of observations.”

Other coauthors of the paper are Stuart Bale, professor of physics and director of UC Berkeley’s Space Sciences Laboratory; Primož Kajdič and Benoit Lavraud of the Université de Toulouse; Emilia K. J. Kilpua of the University of Helsinki; Noé Lugaz, Charles J. Farrugia and Antoinette B. Galvin of the University of New Hampshire; Nariaki V. Nitta of Lockheed-Martin Solar and Astrophysics Laboratory; Christian Möstl of the University of Graz and the Austria Space Research Institute of the Austrian Academy of Sciences.

Written by Astro1 on March 23rd, 2014 , Planetary Defense

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COMMENTS
    Michael Makfinsky commented

    What are the proper preparations (back-up generators, infrastructure power-supply redundancy, etc.), and in the USA, who is “in charge” of preparations – FEMA?

    Reply
    March 29, 2014 at 8:52 am
      Astro1 commented

      According to this article in the IEEE Spectrum, it’s relatively cheap to retrofit transformers with industrial-scale surge suppressors. The same technology would protect against EMP in the event of a nuclear attack. There was a bill in Congress to do that a couple years ago, but it died in the Senate. Newt Gingrich and others are trying to get in revived.

      It would also help to have better solar storm warnings. That could be done with an inexpensive 6U CubeSat.

      Reply
      March 29, 2014 at 10:16 am