SPOKANE, Wash. — On Feb. 12, Friday morning, the coldest day of the recent arctic outbreak across the U.S., a rare ice feature arose in the backyard of one Spokane home.
This is called an "'ice spike". It looks like the ice grew straight up from the home-build water feature in the backyard of Mike Toth, who lives in Spokane.
When water freezes, it expands (one of the few substances knows that has this property). And during very cold nights, standing water will freeze from the shallow edges and work inward. Also, water freezes from the top-down, just like on lakes.
Since the water is expanding into ice, and the water is freezing inward, the last part to freeze will be a hole in the middle. So when the last of the ice freezes, it pushes up through the remaining hole, creating the ice spike.
Ice spikes can form on bird baths if water was still in them on cold winter nights, but weather conditions need to be perfect to create the ice spike, so it doesn't always happen.
The temperature in Spokane Friday morning was 9 degrees, the coldest it's been this entire winter.
