Rivers have always played a critical role in shaping the geographical charisma of a country or city. Besides answering to the utilities, they are a fundamental part of bestowing history, civilization, and most importantly culture. Apart from geographical prominence, rivers resonate with different cultures of different countries. But did you know rivers in colder regions get frozen?
On your voyage to a riverside during winters, you might feel awestruck and surprised at the sight of a glistening bed of ice. That’s how the pristine and tranquil river water changes its characteristics, thanks to the geography and science involved in it. However, thinking that all rivers freeze during the winter season is a complete misconception.
On the contrary, you may think it is the snowfall that has an immediate connection to it. But, here’s a different story. Although snow is a sign of cold temperature, it does not influence the river to freeze. Even if the snowflakes fall into the river during colder climates, it won’t affect the river water to become frozen.
The snowflakes will simply fall into the river water and melt. In fact, anticipating that the snowfall is a factor that influences water to turn into ice is a myth. So, how does river water freeze?
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Can Rivers Freeze?
Saying that rivers can freeze will not be a false narrative. Now that the connection between river freezing and the temperature has been established, here’s outpouring the process in an elucidating way.
In regions where ice forms, the ice formation happens to be seasonal. First off, initial ice bedforms. And if the temperature falls even below the freezing point, the ice bed thickens throughout the winter duration.
As temperature rises in the springtime, the ice in the river melts and decays. During the thickening period, the energy flows out of the ice. On the contrary, energy flows into the river’s ice bed during the decaying period. The flow of energy comprises two elementary models of energy exchange.
While the first one is the radiation of short-wavelength and long-wavelength electromagnetic energy, the other one is the transfer of the heat energy associated with condensation and evaporation (with convection between the surface and air) and with precipitation on its surface.
Though radiation transfers are crucial, the energy exchange in the formation & decay is heat transfer associated with condensation and evaporation with the turbulent convection. As these heat transfers get driven by differences in surface and air temperatures, the duration and extent of ice covers coincide with their average temperatures under the freezing point.
What Temperature Does a River Freeze?
The fact that rivers only freeze when the temperature is below 0 degrees Celsius (or 32° F) for multiple days is already clarified in the geography books. Let’s say you’re planning a visit to a picturesque riverside destination and it’s none other than the Zanskar River in India.
Most of the time, it stays frozen because the air above the river stays below 0 degrees Celsius almost throughout the year. This is one place when those lovely stokes with water in the midst of gigantic mountains give you a thrilling experience! In fact, you’ll be surprised to know that rivers that turn into the ice are also utilized as trekking trails too.
What is a Frozen River Called?
A frozen river is often referred to as a glacier or a slow-moving large mass of ice. A glacier is a huge mass of ice, which moves slowly over the land. This term has been derived from the French word glace (i.e., glah-SAY). This means ice, and glaciers are most often called “rivers of ice.”
There are multiple types of glaciers that are categorized as continental and alpine. While alpine glaciers can be found in the mountainous region, continental glaciers are found in the central regions.
The alpine glaciers flow down the valleys, whereas the dome-shaped continental glaciers flow away from the central region and are unaffected largely by the topography of the land. Take the Antarctic and Greenland ice sheets, for example, these continental glaciers. The smaller ice masses (ice caps) are referred to as continental glaciers.
Some Quick Fact:
Almost 10 percent of the total land area of the world has been covered by glaciers. In other words, glaciers store apparently 75 percent of freshwater worldwide. Glaciers range from the sizes of football fields to even one hundred kilometers long. They occur on continents and in 47 countries. These are harbingers of the changing climate.
Types of Alpine Glaciers
To present a narrative on these “rivers of ice”, here are the types of alpine glaciers.
These glaciers occur when the glacier flows down one steep valley onto the flat plain. The characteristic of such a glacier is bulblike lobes forming at its terminus (the glacier’s end).
The tidewater glaciers form when the glacier flows down the valley and reaches into the sea. As a matter of fact, the tidewater glaciers have numerous icebergs.
These glaciers also best referred to as the ice aprons. They can cling to the steep mountain sides. These happen to be wider but do not feature an extended length. Such a type of glacier is very common in the Alps.
Can Moving Water Freeze in Pipes?
When water changes its form from liquid to solid, it starts from one area. With that, a couple of water molecules get stuck together. It’s due to the fact that they remain cold and do not move around quickly. Upon then, one more water molecule forms ice and gets stuck to the previous molecule. After which, one more molecule gets stuck to the first ones. That’s how it ends up with a large ice crystal that keeps getting bigger as more water molecules start freezing.
If the water is standing still, the process gets simpler. However, if the water is moving (say for example waterfall or water in the pipes), the molecules will likely move away from each other. So, they might not get stuck together easily. That makes it evident for the temperature to play a crucial role in freezing running water in the pipes or natural waterfall.
Once the first few molecules of ice get formed, the rest can freeze easily. Although moving waters can freeze in pipes, indoor pipes in unheated areas stay protected from the outdoor temperature extremes. Colder regions where the temperature is lower than 20 degrees Fahrenheit are prone to causing frozen water in pipes. When pipes freeze, water expands, resulting in the pipes burst.
When pipes get frozen in the colder regions, insulation becomes the best method to unfreeze the water. Insulation protects pipes from getting frozen. And commercial self-adhesive insulation can help prevent the condition.
Can a Waterfall Freeze?
The physics of freezing becomes more complex than still water bodies in moving water. Waterfalls, as a matter of fact, do not stop flowing and freeze over immediately, when temperatures plummet to a freezing point. In fact, when the moving water is continuously mixing, the entire waterfall gets cooled uniformly.
Thus, it takes a longer time for noticeable changes of the state when compared with the still water under similar conditions. The water temperature in the stream/river drops below freezing and it starts the supercooling process. This immediately causes water molecules to slow. They start sticking together in order to form a solid particle made of frazil ice. The tiny discs roughly one millimeter (0.04 inches in diameter) begin the freezing process.
The frazil ice discs clump together when coming into contact. For the case of waterfalls flowing down, the discs start to accumulate against the cold rock, whereas for the free-falling waterfall, the ice clings right to the overhang.
Eventually, frazil ice forms an anchor. From this point, it grows; provided the water temperature stays cold enough for a longer period of time. It creates a column, which runs along the waterfall length. Over time, the stream or the river completely gets frozen, leaving the icy snapshot of waterfalls frozen.
Do Oceans Freeze in Winter?
If the temperature remains cold enough, then the ocean water will freeze. Take the example of the giant slab of frozen ocean water of the polar ice cap at the North Pole, for example. However, if you plan a visit to a beachside during winters, you’d not be surprised at the sight of the shimmering ocean waves, even if the ground gets frozen with ice!
That’s because large water areas do not freeze entirely. And the logic behind the concept is that water, ice, & snow are great insulators of heat. However, they aren’t great as heat conductors. The portions of lakes or rivers exposed to winter air get frozen into ice.
As you can see from the aforementioned narrative, the amount of water that flows through the rivers in the snow-affected regions significantly depends on how much precipitation happens. If less precipitation falls in the form of snow, rivers are likely to discharge less water than they do currently.