Rainwater and melted snow and ice that move too quickly to infiltrate the ground become runoff. Runoff replenishes the water on Earth's surface and helps to continue the water cycle. The next step in the cycle — evapotranspiration — returns water to the atmosphere. The Sun causes evaporation by heating liquid water on Earth's surface. Transpiration — the evaporation of water from pores in the leaves of plants — also releases water vapor into the atmosphere.
Haileigh adams 3rd Hour 1/7/11 The Water Cycle (The Hydrologic Cycle) Definition: Water cycle; the process of which the various forms of water move about the planet in a fairly constant balance. The water cycle has no true beginning and no true ending, except the water changes from a liquid to a solid such as water turns into ice crystals then into snow and also hail. Also there could be turned into water vapor. The cycle is the process by which the water, in whatever form, goes from place to place, ocean to cloud to rainwater to river and back through a cycle of rising air currents, precipitation, runoff and a few other processes. Rising air currents take water, as vapor, up into the atmosphere; with the water form of "evapotranspiration," which is water transpired or from plants and that has evaporated from the soil.
The salinity and temperature of the water influence its density, and the differences in density are the major factor in understanding the formation of currents and the positions of water masses in the sea. In addition, temperature and salinity play major roles in influencing the distribution of plants and animals. The sediments of the sea floor may be divided into lithogenous, hydrogenous, biogenous, and cosmogenous sediments. Lithogenous sediments are the major sediments on the ocean floor. They are derived from the chemical and mechanical weathering of rocks.
• Heat from the sun evaporates water found in the ocean, lakes and rivers. Since impurities are left behind, the water that goes in the atmosphere is cleaner then when it was on earth. • Water also evaporates of the leaves of plants – called transpiration 2. Condensation • This process is the opposite of evaporation – water leaves the vapour state and returns to the liquid state • Lower temperatures favour condensation. • Water droplets formed from condensation that are small remain suspended in the atmosphere in atmosphere in the form of clouds in the sky or fog at ground level.
It absorbs much water vapour from the oceans and land vegetation through evaporation. As this air rises it cools. Eventually the water vapour condenses into clouds and it then creates precipitation. So the equatorial region is both hot and wet. The air rises, then spreads horizontally to the north and south.
Over time layers of shells and sediment are cemented together and turn rock, storing the carbon in rock – limestone and its derivatives. Another way carbon is made in this process is from living things. This is where heat and pressure compress the mud and carbon, over millions of years forming sedimentary rock such as shale. And in some cases, when dead plant matter builds up faster than decay, layers of organic carbon become oil, coal and gas (fossil fuels). The cycle returns carbon to the atmosphere through volcanoes.
The demand for freshwater, especially in arid regions, has driven people to create and implement new and more effective ways to remove salt from water. Desalination occurs naturally as part of the hydrologic cycle. The Sun evaporates water from the ocean. The vapor, condensed by cooler air in the atmosphere, forms rain clouds. The rain from these clouds reaches the ground as pure liquid water.
Removing deep rooted native grasses, shrubs and trees and replacing them with shallow rooted vegetation for annual crops, pastures and other agriculture has significantly increased the amount of water leaking into the groundwater beneath the root system of plants. The annual crops and pastures that replace the native vegetation cannot use all the rain that falls; they only grow for part of the year, and their shallow roots cannot absorb water deep below the soil surface. When there is more water going into the ground
The earth has had the same amount of water for millions of years. This is made possible by the water (hydrological) cycle which circulates water, constantly moving and changing from one state to another (solid, liquid, or vapour/gas). The many interactions of the atmosphere, lithosphere, and biosphere are responsible for this transition of forms, although the core power of the first stage of movement is from the energy of the sun. The sun provides energy to first evaporate liquid to vapour, which starts the other processed involved in this cycle: precipitation, condensation, transpiration, runoff and percolation/infiltration. The Earth's system of cycling water is viewed as the continual displacement of water taken from the ocean, transported through the atmosphere, deposited over land, and ultimately fed back to the ocean.
The Water Cycle 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. Global water distribution For an estimated explanation of where Earth's water exists, look at the chart below. By now, you know that the water cycle describes the movement of Earth's water, so realize that the chart and table below represent the presence of Earth's water at a single point in time. If you check back in a thousand or million years, no doubt these numbers will be different!