GICs
A geomagnetically induced current (GIC) is an electrical current driven through the ground and through long conductors, such as power lines and pipelines, by rapid changes in the Earth's magnetic field. Strong solar storms cause those changes. The late pulse of a high-altitude nuclear EMP produces a similar effect. Large GICs can overheat transformers and trip sections of the power grid, which is how a geomagnetic storm caused the 1989 blackout in Quebec.
Why Preppers Meet GICs
We meet the term because GICs are the mechanism behind long grid outages from space weather and EMP. It turns up whenever families plan for life without power. Grid exposure varies by region, so start by learning the EMP risk areas across the United States. Then look at the record of real events to see whether an EMP has ever happened and what those events did to power and communications. Knowing how GICs work helps you plan your preparedness with confidence instead of guesswork.
