Water is the basis and source of all living being on the Earth, and there is hardly a place on our planet where water is not present. Without exclusion, all the four great constituents of the Earth system contain water: in biosphere water is the component of the living beings; in lithosphere it constitutes a part of various minerals; atmosphere contains water vapors; not to mention the hydrosphere, the sole essence of which is water.
Travelling between those reservoirs in the great hydrologic cycle, water assists in moving materials among all of them, and this movement bears both constructive and destructive consequences for the geological processes of the planet.
The hydrologic cycle refers to the movement of water from one system into another and can be summed up in the following way. The water contained in the ocean evaporates as a result of exposure to solar energy, and the steam moves into the atmosphere where it condenses into clouds due to lower temperatures.
In various forms of precipitation (rain, hail or snow) water falls back to the ocean or land. Some water may then return to the atmosphere by means of transpiration and evaporation. Otherwise it may be infiltrated into the ground through small openings in the soil where it flows into underwater reservoirs and possibly becomes parts of minerals remaining in the lithosphere.
A small amount of water is detained in the biosphere, while the precipitation that does not infiltrate gets back to the ocean as surface runoff. Thus the processes of evaporation, condensation, precipitation, transpiration, evaporation, and infiltration play a key role in the hydrologic cycle. (Murck, Skinner, & Mackenzie, 2007)
Travelling about the planet in the endless turnover, water forms a closed cycle, with its constant total amount distributed among various salty, frozen, underground or fresh reservoirs. However stable the total water amount is, movements between the reservoirs may be rapid and unbalanced, leading to catastrophic consequences (for example, floods).
But even in normal course of interaction between water and land, water leaves its indelible print on the planet’s image. Streams and rivers cut through the landscape in their channels created by constant movement of water, and may cause erosion or deposition depending on the character of the movement. The movement of water in the ocean bears a decisive impact on the coastal line.
For example, waves moving onto the shore thrust the most of their energy upon the most protruding parts of the coastal line, frequently creating the rough landscape of coastal cliffs; the reduced energy of the waves that get to the deeper bays brings along sand and forms vast fragments of beaches (“Wave refraction”, n.d.).
The combination of erosive and depositional processes forms a variety of coastal forms depending on the wave angle and direction, and the amount of the sediment available for transporting along the coastline (“Coastal landforms”, n.d.).
One of the decisive factors defining the present and future of the planet surface is the sea level. According to the prognoses, the recent global warming will have caused the sea levels to rise up to 3 feet by the end of the century in Southern UK (“Sinking England, n.d.). That perspective necessitates cooperation between man and nature: for instance, the salt marshes of Essex could be an efficient natural barrier against the sea, since they absorb the energy of the waves (“Sinking England”, n.d.).
The ever-existing hydrologic cycle is an instance of the natural balance on the planet. Human activities trigger dramatic shifts in the distribution and movement of water around the Earth, which may lead to tragic consequences for the planet. Therefore, a deep understanding of natural processes is vital in order to efficiently cooperate with the nature and prevent the planet from being thoughtlessly wasted.
Coastal landforms. (n.d.). [Animation]. Retrieved from http://www.wiley.com/college/strahler/0471669695/interactivities/flash/waves_wind/waves_wind2.htm
Murck, B. W., Skinner, B. J., & Mackenzie, D. (2007). Visualizing geology. San Francisco, CA: John Wiley & Sons, Inc.
Sinking England. (n.d.). [Video]. Retrieved from http://www.wiley.com/college/murck/0471747270/ngs_videos/sinking_england/index.html
Wave refraction. (n.d.). [Animation]. Retrieved from http://www.wiley.com/college/strahler/0471480533/animations/ch19_animations/animation2.html