how did this happen?
I have to say that I love those spikes - what a perfect ice cube removal device! Isn't physics great?
To camp on to weird ice "phenomena", I'll mention an ongoing war in my household. Ice cube tray with a loaf of ice one-half inch to three-quarters of an inch above the level of the tray (Think quonset hut shape, here.) Hub insisted I was filling the ice cube trays too full. Huh? Even I (she says, blushingly) can't change where water finds its level. Problem was solved when we found a hairline crack in one of the cube trays, slowly leaking water onto the tray below and thus forming uber-cubes, higher than they had a right to be.
I think I like being able to command water to defy physics more than I like the real explanation, but at least the war is over and the faulty tray is retired.
So many interesting things in our freezers!
What are Ice Spikes?
Ice spikes are odd ice structures that occasionally grow out of ice cube trays. Unlike some of the strange things you might find growing in your refrigerator, ice spikes are made of nothing but ice. Ice spikes are the result of physics, not biology.
How do Ice Spikes Form?
Ice spikes grow as the water in an ice cube tray turns to ice. The water first freezes on the top surface, around the edges of what will become the ice cube. The ice slowly freezes in from the edges, until just a small hole is left unfrozen in the surface. At the same time, while the surface is freezing, more ice starts to form around the sides of the cube.
Since ice expands as it freezes, the ice freezing below the surface starts to push water up through the hole in the surface ice (see diagram). If the conditions are just right, then water will be forced out of the hole in the ice and it will freeze into an ice spike, a bit like lava pouring out of a hole in the ground to makes a volcano. But water does not flow down the sides of a thin spike, so in that way it is different from a volcano. Rather, the water freezes around the rim of the tube, and thus adds to its length. The spike can continue growing taller until all the water freezes, cutting off the supply, or until the tube freezes shut. The tallest spike we've seen growing in an ordinary ice cube tray was 56mm (2.2in) long.