The light green areas can be considered "deserts". You might expect the Sahara area in Africa to be a desert, but did you think that much of Greenland and Antarctica are deserts? On average, the 48 continental United States receives enough precipitation in one year to cover the land to a depth of 30 inches 0. Have you ever watched a raindrop hit the ground during a large rainstorm and wondered how big the drop is and how fast it is falling?
Or maybe you've wondered how small fog particles are and how they manage to float in the air. Source: Lull, H. Publication No. Earth's water is always in movement, and the natural water cycle, also known as the hydrologic cycle, describes the continuous movement of water on, above, and below the surface of the Earth. Water is always changing states between liquid, vapor, and ice, with these processes happening in the blink of an eye and over millions of years.
Rain and snow are key elements in the Earth's water cycle, which is vital to all life on Earth. Rainfall is the main way that the water in the skies comes down to Earth, where it fills our lakes and rivers, recharges the underground aquifers, and provides drinks to plants and animals. For the water cycle to work, water has to get from the Earth's surface back up into the skies so it can rain back down and ruin your parade or water your crops or yard. It is the invisible process of evaporation that changes liquid and frozen water into water-vapor gas, which then floats up into the skies to become clouds.
The air is full of water, as water vapor, even if you can't see it. Condensation is the process of water vapor turning back into liquid water, with the best example being those big, fluffy clouds floating over your head.
And when the water droplets in clouds combine, they become heavy enough to form raindrops to rain down onto your head. You can't see it, but a large portion of the world's freshwater lies underground. It may all start as precipitation, but through infiltration and seepage, water soaks into the ground in vast amounts.
Water in the ground keeps all plant life alive and serves peoples' needs, too. Note: This section of the Water Science School discusses the Earth's "natural" water cycle without human Ice and glaciers are part of the water cycle, even though the water in them moves very slowly.
Ice caps influence the weather, too. The color white reflects sunlight heat more than darker colors, and as ice is so white, sunlight is reflected back out to the sky, which helps to create weather patterns. Read on to learn how glaciers and ice caps are part of the water cycle. Yes, water below your feet is moving all the time, but, no, if you have heard there are rivers flowing below ground, that is not true. Water moves underground downward and sideways, in great quantities, due to gravity and pressure.
Eventually it emerges back to the land surface, into rivers, and into the oceans to keep the water cycle going. Evapotranspiration can be defined as the sum of all forms of evaporation plus transpiration, but here at the Water Science School, we'll be defining it as the sum of evaporation from the land surface plus transpiration from plants. Freshwater on the land surface is a vital part of the water cycle for everyday human life. On the landscape, freshwater is stored in rivers, lakes, reservoirs, and creeks and streams.
Most of the water people use everyday comes from these sources of water on the land surface. Acid rain can be manmade or occur naturally. The audio, illustrations, photos, and videos are credited beneath the media asset, except for promotional images, which generally link to another page that contains the media credit.
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Any interactives on this page can only be played while you are visiting our website. You cannot download interactives. The cryosphere contains the frozen parts of the planet. It includes snow and ice on land, ice caps, glaciers, permafrost, and sea ice. As the world warms due to increasing greenhouse gases being added to the atmosphere by humans, the snow and ice are melting. There are four main stages in the water cycle. They are evaporation, condensation, precipitation and collection.
Let's look at each of these stages. Hence water enters lithosphere. As water precipitates, some of it is absorbed by the soil.
This water enters into the process of transpiration. Transpiration is a process similar to evaporation where liquid water is turned into water vapor by the plants. The roots of the plants absorb the water and push it toward leaves where it is used for photosynthesis.
The extra water is moved out of leaves through stomata very tiny openings on leaves as water vapor. Thus water enters the biosphere and exits into gaseous phase. As the water pours down in whatever form , it leads to runoff.
Runoff is the process where water runs over the surface of earth. When the snow melts into water it also leads to runoff. As water runs over the ground it displaces the top soil with it and moves the minerals along with the stream. This runoff combines to form channels, rivers and ends up into lakes, seas and oceans. Here the water enters hydrosphere. Some of the water that precipitates does not runoff into the rivers and is absorbed by the plants or gets evaporated.
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