I left a jar full of water and parsley on the balcony for a few winter nights, I just forgot about them.
Later when I checked the ice had formed weird shapes, which were air pockets. It seems like the air tried to move away or towards the parsley WHILE the water was freezing.

The jar was placed standing up with the lid open, so gravity shouldn’t have had much effect on these air pockets, as they are moving sideways.
It was also not subjected to any tremors or movements.

Here’s more pictures: Imgur Album