A NASA-funded study found that a solar flare the size of one that occurred in 1921 could leave 130 million people without power, and cause a collapse of the power infrastructure in the Northwest, Midwest and most of the East Coast.
Similar to the electromagnetic pulse (EMP) caused by nuclear weapons, a geomagnetic storm could induce currents that fry anything electrical. In 1989, a storm melted transformers and knocked out power for 6 million people in Quebec. The one in 1921 is estimated to have been 10 times stronger, and it knocked out all communications east of the Mississippi.
