I grew up just a few miles from where that video was shot. We had that happen several times in the '60s. After a very cold winter, the ice would grow to 6 or more feet thick. If the spring is cold, it takes a long time to melt, and the air can be quite warm before it thaws. This causes the ice to crystallize into long thin crystals as you can see in the video. It is also very weak.
The wind ordinarily will push the ice to the shore and the shore stops it from moving. When ice is in the condition of weak crystals, it just moves up the shore and piles up as in the video. This regularly happened during the very cold '60's and early '70's.
The composition of the ice surprised me.Heard the story on the
radio this morning.When watching the video I was expecting big
thick slabs of ice.Thanks for the explanation
When we lived in northern Wi we just had floods when the ice melted