Quick Answer
Electricity during a lightning strike travels through the ground as an electrical current, often referred to as a ground current, which can cause damage to electronic devices and pose a risk to people nearby.
Conductivity Path
When a lightning strike occurs, the electrical current seeks the path of least resistance to the ground. This path is typically through the water in the soil, which is a good conductor. The water content in the soil can vary depending on factors such as soil type, moisture levels, and location. For example, areas with high clay content tend to have higher water retention and conductivity.
Ground Current Danger
The ground current associated with a lightning strike can cause significant damage to electronic devices and can also pose a risk to people nearby. This risk is often underestimated, and ground current can be as lethal as a direct strike. The ground current can travel through any conductive path, including power lines, metal pipes, and even the human body. In the United States, the average ground current from a lightning strike can range from 1-10 kiloamperes (kA), but it can reach up to 100 kA in extreme cases.
Precautions and Safety Measures
To minimize the risk of damage from ground current, it’s essential to take precautions during a lightning storm. This includes turning off electronic devices, unplugging sensitive equipment, and avoiding contact with metal objects. People who work with electrical systems, such as electricians and lineworkers, are particularly vulnerable to ground current and should take extra precautions during a storm. In some cases, grounding systems can be installed to protect against ground current, but these systems require regular maintenance to ensure they are functioning properly.
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