Frozen lake produces almost out-of-this-world sounds when skipping rocks

A man is shocked by the strange sound coming from a frozen lake after he threw a skipping rock at it.

Cory Williams and his girlfriend were walking around the woods in Anchorage, Alaska when they encountered a frozen lake. Williams thought it was a perfect opportunity to skip rocks over the lake, but he never expected the rock to make a 'chirping and pinging' sound.

Williams uploaded a video on YouTube in October 2014, which showed his awe and surprise when he heard the stone make a strange 'chirping' sound when thrown over a frozen lake.

The only thing he had expected when he threw the stone into the frozen lake was that it would not go down in the water and would be perfect for skipping. But the strange sound that it created was a total joy for him.

"Whoa!" he can be heard exclaiming in the video. "I've gotta do that again."

He quickly searches for another rock and finds another perfect skipping stone. With his interest piqued, he gives the stone a good throw. To his delight, the same chirping sound returned as the stone bounced on the icy surface.

Williams then declares in the video that it was the "coolest sound" he had ever heard. Excited, he asks his girlfriend as well to try skipping the rock. Although she does not seem very good at skipping rocks, she tries it upon being insisted by Williams.

Sure enough, the same chirping sound returned yet again delighting the couple, who by this point of time cannot stop themselves from laughing.

According to Inspiring, Williams later revealed on his YouTube page why the incident had caused him much elation. 'Growing up in California, I rarely experienced temperatures below freezing, so the joys of cold weather are all new to me,' he wrote.