Steve Asked:
How does lightning kill multiple animals in a single strike?
The Answer:
Herd animals that gather in groups are typically killed not by a direct lightning strike, but by the current flowing through the ground from the strike. What happens is that the lightning strike often hits a tree or the ground near where the animals are gathered and the electrical current then spreads along the surface of the ground and shocks any people or animals in the vicinity of the strike. Electrical current literally goes up one leg and down the other back into the ground. Eventually, the current dissipates as it flows further and further from the strike point.
For example, 23 cows were killed instantly after lightning struck the metal fence they were standing next to during a storm in Texas recently. Since the cows were all lined up next to the fence, they were all impacted by the lightning strike and burn marks on their stomachs indicated that electrical current had flowed through their bodies, killing them instantly.
The average lightning strike can carry more than 20,000 amps of electrical current, more than enough to kill a herd of cattle by passing through their nervous system and instantly stopping their hearts. It doesn’t matter whether the animals are touching or not, or how close they are to each other. The only thing that matters is how close they are to the strike point and how powerful the strike is.
We call this phenomenon “Step Potential”.
Step potential is the voltage between the feet of a person or animal standing near an energized object. Interestingly, animals are even more vulnerable than humans to step potentials because their legs are farther apart, so ground currents can travel more easily through their bodies.
How far can the ground current travel?
Hazardous step potentials can occur at a significant distance away from any given strike and the more current that is pumped into the ground, the greater the hazard. Animals have been reported to have been killed at distances over 250 feet from a lightning strike which shows just how far electrical current can travel through the ground.
Quick facts
- Lightning causes more than 80% of all accidental livestock deaths (from USDA)
- Over 100,00 farm animals are killed by lightning annually
- 85,000 chickens were killed due to a lightning strike in Florida
- 835 Sheep died due to a lightning strike in Utah
- 323 reindeer in a herd were killed by lightning in Norway
- 250 pigs died in Thailand due to a single lightning strike
- 68 Cows died due to a lightning strike in Australia
- 52 Cows died in Uruguay when lightning struck nearby wire fencing
Did you know?
- Whether or not you believe in climate change, storms are becoming more frequent and violent, and records show large animal deaths by lightning strikes are on the rise.
- A lightning strike is a common cause of death for wild Mustang horses that roam throughout the West because the flat terrain at higher elevations is frequently struck by lightning during a storm and if the horse is the tallest object on the plain he becomes the lightning conductor.
- You may not realize that your livestock are dying from lightning strikes since animals electrocuted by lightning often do not show any burns on their bodies.
- 21 Cattle were killed when lightning struck a metal feeder they were eating from in McCook County, South Dakota — at an estimated loss to the rancher of about $45,000.
- In 2016, Grade I winner “Brilliant Speed” was struck by lightning and killed. Brilliant Speed finished in the money in the G1 Belmont Stakes, G1 Breeders’ Cup Turf, G1 Jamaica Handicap, G1 Sword Dancer, and G1 Woodford Reserve Turf Classic.
The Engineering Experts at E&S Grounding Solutions
