A Close Study of Water on Earth
The study of water in science covers many different topics but the idea of water in the air and on Earth is one of the most critical things to understand. This covers topics such as the water cycle, water and erosion, and fresh and ocean water. Knowing about these topics will make it easier to understand other topics such as certain natural disasters and helps to explain everyday phenomena.
A good beginning to the study of water on earth is the water cycle. According to E.C Pielou’s Fresh Water, the water cycle is a process where water moves around the earth and into the sky. This process does not have a beginning or end but it does have these steps. Water can fall to the ground as rain, snow or ice, where it can go onto the land or into the sea. The water can then go back into the air as vapor, the gas state of water, in the air the vapor condenses (comes together) into clouds. Those clouds can then allow more water to fall to the Earth and the cycle repeats. This cycle can take anywhere from minutes to thousands of years to complete but it will always continue to repeat itself.
According to Earth Sciences: Notable research and Discoveries by Kyle Kirkland, some water can be absorbed into the ground, this water is called groundwater. Groundwater exists in the saturated zone where water fills every small space in the ground, when an area has a large enough saturated zone to supply a well, that area is called an aquifer. Above that is the vadose zone just below the surface, that area is often dry since gravity pulls water downward. The place where these zones meet is called the water table, the location of which depends on the amount of rainwater that has seeped below the ground. A higher water table means that more rainwater has seeped.
Water can do things. According to The New Children’s Encyclopedia: With more than 4,000 indexed entries and 2,500 full-color illustrations, water is one way things can be eroded. Erosion is when rock or soil is worn away by the effects of water, wind, ice, and gravity. The three ways water can erode things are through rain, rivers, and the ocean. According to National Geographic, rain can erode soil in four ways. Splash erosion is when the impact of a falling raindrop scatters tiny soil particles, sheet erosion is when rain removes soil in thin layers, rill erosion is when soil is removed by rainwater gathering in small streams on the ground, and gully erosion is when soil particles are carried for short periods of time by rainwater gathered in streams or in cracks. Erosion can also occur through rivers, according to Geography AS Notes, rivers can erode vertically making the river deeper, or horizontally making it wider. It can erode through hydraulic action where the river picks up rock pieces, abrasion where the materials the river carries rubs against pieces of rock and removes them, corrosion where the water dissolves certain types of rock, cavitation where air bubbles are squeezed into small spaces such as cracks in rock, implode, and create a shockwave that weakens the rock, and attrition where rocks the river is carrying knock together and break apart. The last way water can erode is through the ocean. According to Encyclopaedia Britannica this occurs through waves crashing onto shore and picking up sand and pebbles. The sand and pebbles that are picked up will grind along the rock in the coast and gradually wear down the rock into sand.
One of the places water on earth can be found is in rivers. According to the textbook Water on Earth, a river will often have smaller rivers and streams flowing into it, those smaller streams and rivers are called tributaries. A river combined with its tributaries will drain an area of land, that area is called a watershed or drainage basin which are separated from each other by divides, areas of higher land. At the end of a river it will start to flow more slowly as it reaches a large body of water such as a lake or ocean, this can form a delta which made mostly out of mud on a flat surface. Sometimes a river will flood because of heavy rainfall or snow melt, when it does that it can drop off (deposit) material it’s carrying and the area formed by the material is called a floodplain. The behavior of water in a river is affected by gradient, the change in elevation over a certain distance because a higher gradient allows the river to flow faster. It is also affected by discharge which is the amount of water a river or stream carries at a given amount of time, more discharge means that the river will flow faster.
The ocean is another place where water can be found, according to Jennifer Hoffman’s Science 101: Ocean Science, the water in the ocean is often moving. There are currents in the water which are affected by wind, a wind blowing parallel to the shore will cause water at the surface to move away from shore and deeper water will replace it, there are many of these currents on the surface of the ocean and they often move at speeds of 0.3 to 1.5 feet per second. When a faster current interacts with a slower one, it will create swirls of water that break off from the current called eddies. At the coast waves can bounce backwards at a steep shoreline, slope and break at a less sloped shoreline, or bend as the pass through narrow openings and around obstacles. The water will also rise and fall regularly at the coast because the gravitational pulls of the sun and moon cause the water to bulge towards the side the sun and moon is as shown in figure 1.
The water cycle, groundwater, how rail, rivers, and the ocean erodes, as well as how water behaves in rivers and oceans are interesting topics to study because they allow for many new ideas to be formed. For example, perhaps water that is evaporating can be artificially condensed into liquid water that can be drank. The locations of floodplains and how much they flood should be taken into consideration when building there. The height of the tides also must be considered when building at shorelines. The erosive ability of an ocean at a certain coast as well as the erosive ability of a river at one location are other things to be considered when building near rivers and coasts to prevent damage to structures. These are only a few of the ideas that can can be formed from the study of water on earth.
Dorling Kindersley Limited. The New Children’s Encyclopedia: With more than 4,000 indexed entries and 2,500 full-color illustrations. New York: DK publishing, 2009.
A part if this book is essential in having a basic understanding in erosion and water. It explains the ways water relates to erosion. It also contains pictures and diagrams that show two ways water relates to erosion.
Hoffman, Jennifer. Science 101: Ocean Science. New York: HarperCollins Publishers, 2007.
Two chapters in this book are critical in understanding the behavior of the water in the oceans. It explains and defines major concepts related to the behavior of ocean water. There are many pictures that show those concepts.
Holt, Rinehart, and Winston. Water on Earth. Austin: Holt Science ; Technology, 2005.
Some sections of this book are essential in understanding rivers and how water behaves in them. It defines important words that are used to describe river water and parts of rivers. It also includes many pictures and diagrams to help explain certain topics.
Jackson, Alex. “River Processes.” Geography AS Notes. Updated August 2, 2014. https://geographyas.info/rivers/river-processes/.
A part of this webpage is critical in understanding how rivers erode rock. It provides definitions on the different ways rivers erode.
Kirkland, Kyle. Earth Sciences: Notable Research and Discoveries. New York: Facts On File, Inc, 2010.
A small section in this book is essential in understanding groundwater. It defines important vocabulary words that relate to the topic of groundwater.
Pielou, E. C. Fresh Water. Chicago: The University of Chicago Press, 1998.
The first chapter of this book is critical in understanding the water cycle. It defines and explains each step in the water cycle. It also provides a diagram showing each step.
Sue, Caryl. “Erosion.” National Geographic. Updated March 20, 2018. https://www.nationalgeographic.org/encyclopedia/erosion/.
This webpage includes a part that is essential in understanding how rainwater is related to erosion. It defines the different terms used to describe rainwater erosion.
The Editors of Encyclopaedia Britannica. “Erosion.” Encyclopaedia Britannica. Published March 05, 2018. https://www.britannica.com/science/erosion-geology.
A part of this webpage is critical in understanding the relationship between the ocean and the erosion of coasts. It explains the ways the ocean can erode coasts.
The Trustees of Indiana University. “Introduction to Oceanography.” G115. Accessed november 27, 2018. http://www.iupui.edu/~g115/mod12/lecture05.html
This webpage provides a figure that is essential in understanding the effect of the positions of the moon and sun in relation to the earth on the tides.