System Earth, Part 1
Print System Earth, Part 1 Reading Comprehension
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||phosphorous, regeneration, geosphere, nonliving, biosphere, nonexistent, electromagnetic, component, hydrosphere, organic, ultraviolet, sphere, interior, volume, core, solar
||Our Earth, In System Earth
System Earth, Part 1
By Trista L. Pollard
1 Our planet is an important member of the solar system. However, did you know that the Earth is also a system? A system is an organized group of related objects or components that work independently and interact to create a whole. The sizes of systems vary; however, all systems have boundaries. Most systems, like the Earth system, have matter and energy that flow freely through the system. Our Earth system runs smoothly due to the combination of smaller components that link our planet together. To understand our system, we need to start with matter and energy.
2 Matter, which is anything that has mass and takes up space, is one of the two most basic components of our universe. Matter can be in the form of atoms, molecules, or larger objects both living and nonliving. Energy, the other basic component, is the ability to do work. The transfer of energy comes in many forms like heat, light, or electromagnetic waves. Scientists, to describe systems, can use these two components, specifically how matter and energy are transferred within a system. How matter and energy are transferred determines whether the system is closed or open. A closed system is a system where only energy is transferred or exchanged with its surroundings. Matter is not part of this exchange. An open system includes the transfer and exchange of both matter and energy with the system's surroundings. All of the systems on Earth are classified as open systems. However, the Earth system as a whole is considered a closed system because there is a limit to how much matter is exchanged.
3 Our Earth system has four spheres: the atmosphere, the biosphere, the hydrosphere, and the geosphere. Our atmosphere is made of gases that surround our surface. The breakdown of gases is 78% nitrogen, 21% oxygen, and 1% other gases. Without it, our air supply would be nonexistent. Our atmosphere also shields us from the harmful ultraviolet rays that are given off by the sun. The hydrosphere, which covers about 70% of our surface, includes our planet's water supply. About 97% of our surface water is found in our oceans and 3% is considered fresh water. The only water not included in this sphere is the water that is found in our atmosphere. As you may have guessed, our geosphere is the solid part of earth that we stand on each day. This sphere includes all of the rock and soil on our planet's surface and on its ocean floor. It also contains the interior parts of Earth both solid and molten. The interior of our planet accounts for the largest volume of matter on Earth. The last sphere, the biosphere, includes all life on our planet, which exist in the geosphere, hydrosphere, and atmosphere. It also contains organic matter that has not been decomposed. When this matter decomposes, it becomes part of the other three spheres in the system. The biosphere's boundaries extend from the ocean depths to a few kilometers above our planet's surface.
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