Lightning FAQ: Can a lightning bolt 'split' and strike in more than one place on the ground?
It is a common occurance for a lightning channel to 'split' and strike two, three or even more different spots on the ground (image at right). The multiple ground points can range in separation distances from several feet apart to miles apart.
Split-channel flashes occur when subsequent return strokes are spaced apart for longer amounts of time, allowing the electrical conductivity of the air along the original lightning channel to dissipate. If the channel conductivity decays enough, the next stroke must form a new stepped leader and a new path to ground midway down to the ground.
Normally the strokes occur in rapid succession, leaving no time for the original channel to decay- allowing subsequent strokes to follow the same path.
Each channel 'split' flashes one at a time, in other words the lightning doesn't flash down each path simultaneously.
This slow-motion animation depicts a split-channel flash. Notice that both strikes use a common path halfway to the ground:
In still-camera photographs of 'split channel' flashes (see two photos at the bottom of this page), all of the return strokes appear together as a 'forked flash' on the exposure, rather than as seperate flashes. If you were to photograph the strikes in the animation above, they would appear together:
Terry Pallister, a lightning photographer in New Orleans, Louisiana, has captured fascinating digital video shots of split-channel flashes that clearly show each separate return stroke following different paths to ground in the same strike. The following is a slow-motion animation of two frames of one of Terry's video clips:
image copyright © by Terry Pallister - http://www.skyflashes.com
You can see the divergence or 'pivot point' a short distance above the ground where the lightning channel divides. A special thanks to Terry for allowing his work to appear here. Be sure and visit his site at skyflashes.com.
Photos of split-channel CG lightning strikes
Below: An unusual split-channel flash with at least five ground connections. (click to enlarge):
Below: A split-channel flash with ground points about 2 miles apart. The divergent point is near the top of the photo (click to enlarge):
Below: A close-up split-channel flash with ground points about 400 feet apart. The divergent point is out of view above the photo:
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