Electrocution: New Way to Erode Mountains

Read this article about how lightning can make big changes to mountaintops.

What specific effects can lightning have on huge mountain rock formations?
Lightning carries large amounts of heat energy. Temperatures can reach up to 54,000° F (30,000° C). How does this heat affect rock that is struck by lightning?
According to the article, how do scientists find lightning strike locations?
Why are the effects of lightning on mountaintops only seen at very high altitudes?