American Winter Freeze Results In Some Cool Natural Phenomena
On Monday, January 27th, residents of Ohio, Pennsylvania and Illinois woke up to a special treat - Giant snow rollers. Often described as nature's snow sculptures, the beautiful giant columns are a rare meteorological phenomenon.
Snow rollers are essentially snowballs, which are formed when large amounts of snow gets blown along the ground by wind. However, unlike normal snowballs, these are cylindrical in shape and mostly hollow in the middle. That is because the inner layer which is the first to form, is often very weak and thin and prone to blowing away, leaving behind a snow sculpture that resembles a Swiss roll or sometimes even a donut.
Last seen in this area about a decade ago, snow rollers only form under very special conditions. First, the ground has to be icy enough so that the snow does not stick to it. Then, the snow has to be wet and at a temperature that is close to its melting point. Also, in order for the rollers to form they have to be able gather more snow, which means that their life has to begin at the perfect incline so that the gravitational pull can help roll it down. Not only that, the wind conditions have to be just right. Strong winds can destroy the fragile structure, while weak ones will not provide them with the oomph they need. It is therefore not surprising that these nature's sculptures are rarely seen.
The snow rollers are not the only strange phenomenon caused by this year's severe winter. As the polar vortex loosened its frigid grip on the East Coast of the United States in early January, it left behind thousands of gigantic, spherical ice balls on the shores of Lake Michigan. The ice boulders were created when the weather warmed and melted the ice sheet covering the lake, resulting in large chunks, that got eroded by the waves and transformed into beautiful icy 'bowling' balls.
If that is not exciting enough, on January 4th, residents of many cities in Ontario, Canada were jolted awake in the middle of the night by several loud booms caused by a phenomenon called cryoseism.
Also known as 'frost quakes' they occur when temperatures drop so low that rain that has penetrated deep underground, freezes.
Since water expands when frozen, it puts pressure on the rocks that lie underneath. The stress continues to build until the rocks finally crack under the pressure, resulting in a slight shift in the ground and noises that are loud enough to rattle nerves.
Have you experienced any of these phenomena? If so be sure to share them with us, by adding you comments below.
Reading Comprehension (3 questions)
- What are all the conditions that have to be in place in order for snow rollers to form?
- What caused the icy balls on Lake Michigan?