Why does freezing water in an ice tray only sometimes form ice cube ‘stalagmites’?

Question

[Picture](https://imgur.com/gallery/MKDz4dx)

In: Physics

Answer 1

IT is pretty simple – ice expands as it freezes. Ice first forms around the outside of the ice cube, and over the top, locking the water inside. But as that water continues to freeze, it expands, creating a crack in the ice and forcing water through it. That ice freezes around the outside, and more water is pushed upwards through it, forming a tube. Water keeps being pushed out and freezing on the top – forming a spike.

This can also happen on freezing puddles and small lakes, forming enormous spikes.