GRAND RAPIDS, Mich. (WOOD) — Amanda Simon had the strangest thing happen to her ice as it melted in the warm temperatures this spring. The slab that served as an ice rink was splitting apart into long rods of ice, perpendicular to the ground.

Here’s the video:

What you are seeing here is something called “candle ice,” named after the tiny candle-like structures the ice is shaped as.

Candle ice only happens when ice is decaying. So much so that another name for it is “rotten ice.” Candle ice is exceptionally unstable and fragile, and usually forms on surfaces of water like lakes and the sea.

In this case, the ice rink likely had enough water resting on its surface that it began decaying in a similar way to that of ice on a body of water.

HOW DOES IT FORM?

Candle ice forms when the ice is ready to break down. Solar energy begins melting the ice from above, and the weakest portion of the slab is located on the boarders of the ice crystals inside the slab. Sun and water work together to erode away along these impurity lines, creating pillars from the slab.

Candle ice is very unstable, often shattering with very little external force. While it is unsafe to walk on without solid ground below it (as seen in this instance here) it can be very fun to break apart by hand on a warm spring day.