LIGHTNING & TREES
by Grandpa Cliff
Oct 21, 2005
Each year in the United States, more than a million trees are struck by
lightning. Lightning also strikes almost a thousand people yearly, about a
hundred of whom die. Most of the those deaths occur as a result of people
taking cover under a tree that was struck by lightning.
A lightning bolt can have a temperature as high as 55,000 oF, which is
about five times as hot as the surface of the sun. After lightning strikes a
tree, it's electricity goes through the tree into the ground. The voltage of
the electrical charge in lightning is about 10 million to 100 million volts.
Lightning often travels down the tree through the outer sapwood and
cambium. Such high lightning temperatures cause the water to
immediately turn into steam. But, steam takes up much more room than
liquid water does. As the water instantly expands to become steam, an
explosion results. That knocks off the bark of the tree, and sometimes
some of the outer sapwood as well. If the lightning travels more deeply in
the tree, the whole tree can be blown apart.
The trees which get struck most frequently are Ash, Black Locust, Catalpa, Elm, Maple, Oak, Pine, Poplar, Spruce, and Sycamore. Beech, Birch, and Horse Chestnut get struck very seldom.
June 11, 1999 near Denver, Colorado
The outer part of the sapwood is shredded. Some of the shreds are still attached to the trunk.
June 8, 2002 Oakville, Washington
Notice what looks like a line of burned wood in the middle of
the lightning damage. Near Boulder, Colorado. May 24, 2004.
Notice the light edge to the dark bark on the tree on the right.
That is where the tree tried to heal itself.
Colorado Springs, Colorado
In the left photo, the missing bark can be seen from the top to the ground.
Two views of the same tree. The right photo gives us an idea of how far the bark was thrown.
June 30, 2005 in Litchfield, New Hampshire
Click HERE to go to another website with many interesting photos of two trees that had been struck by lightning. One photo shows a tree that had completely healed its exploded bark.
And here is another website with many photos.
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