David B. Fankhauser, Ph.D.
Professor of Biology and Chemistry
University of Cincinnati Clermont College
Batavia OH 45103
This tree was struck up the valley from my house and produced a very interesting spiral pattern of damage. Thanks to my student Kasey Stopp for bringing it to my attention.
My hypothesis: Tree trunks grow in spirals over the years, providing conductive channels down which lightening electricity can easily flow. The bark has been blown off above these channels as the charge is transmitted.
source: David B. Fankhauser, PhD, Clermont College