SMES - Introduction to Cycles (Lesson)
Introduction to Cycles
We have already identified the value of Earth's location as the "3rd rock" from the sun. The type of star and the distance of a planet from the star affects the two major parts of the system that control the surface temperature of a planet. The atmosphere of a planet affects the planetary temperature system, which determines the temperature of that planet. No matter how substances within a closed system interact with one another, or how they combine or break apart, the total weight of the system remains the same. The idea of atoms explains the conservation of matter: If the number of atoms stays the same no matter how they are rearranged, their total mass stays the same. The following geologic characteristics allow Earth to remain habitable to humans:
- Liquid outer core (coupled with the planet's rotation) and a thick atmosphere
- Viscous mantle (slow motion)
- Slow-motion of crust and upper mantle (lithosphere) of 3-5 centimeters per year
The crust and top part of the mantle that is solid are called the lithosphere (sphere of rock). The lower part of the upper mantle that is composed of partially molten or melted rock is called the asthenosphere. Plate tectonics demonstrate how the lithosphere moves over the asthenosphere. Volcanoes occur where the plates collide or move apart, and in areas known as "hot spots".
The nutrient atoms, ions, and molecules that organisms need to live, grow, and reproduce are continuously cycled from the non-living environment (air, water, soil, and rock) to living organism (biota) and then back again in what is called literally life-earth-chemical cycles commonly known as the nutrient cycles or the biogeochemical cycles.
Along with energy, water, and several other chemical elements cycle through ecosystems and influence the rates at which organisms grow and reproduce. About 10 major nutrients and six trace nutrients are essential to all animals and plants, while others play important roles for selected species. The most important biogeochemical cycles affecting ecosystem health are the water, carbon, nitrogen, sulfur, and phosphorus cycles.
Click through the following presentation for an introduction to biogeochemical cycles.
RESOURCES IN THIS MODULE ARE OPEN EDUCATIONAL RESOURCES (OER) OR CREATED BY GAVS UNLESS OTHERWISE NOTED. SOME IMAGES USED UNDER SUBSCRIPTION.