Cycles
Rock Cycle
Sedimentary, igneous rock, Metamorphic rock
There are five processes: metamorphism, weathering and erosion, cementation and compaction, melting, and cooling and solidification.
Weathering and erosion create sedimentary rocks.
When water, wind, air or gravity transport the sediment, it's known as erosion.
Erosion process layers the sediment onto itself, and gravity forces the bottom layers to be moved into the Earth. This process is called compaction.
When silica and calcite are added to the compacted rock, they are cemented together
As the bottom layers of sedimentary rock are moved further into the Earth, they are heated and melt, then they heat rock that's buried in the Earth's crust, transforming it into metamorphic rock. Then it cools and solidifies. This cooled rock is called igneous rock.
The metamorphic rock and igneous rock are weathered down and eroded, when they become sedimentary rock. They are deposited, layered and the cycle starts all over again.
Water Cycle
The sun is responsible for its two major components: condensation and evaporation.
When the sun heats the surface of water, it evaporates and ends up in the atmosphere as water vapor.
It cools and rises, becoming clouds, which eventually condense into water droplets.
Depending on the temperature of the atmosphere and other conditions, the water precipitates as rain, sleet, hail or snow.
Nitrogen Cycle
consists of nitrogen fixation, nitrification, denitrification, and decay.
Nitrogen Fixation is when nitrogen gas from the air is made into nitrogen compounds.
Nitrification is when ammonia in the soil is converted to nitrates. Nitrification is performed by nitrifying bacteria. Plants absorb the nitrates and use them to make proteins.
Denitrification is when nitrogen gas becomes part of the atmosphere.
Decay is when organic nitrogen compounds of dead organisms and waste are returned to the soil.
Through the nitrogen cycle, food-making organisms obtain the necessary nitrogen. The nitrogen cycle does not supply enough nitrogen to support plant growth. In these soils natural or artificial fertilizers, containing nitrates or ammonium compounds, are needed.
Carbon Cycle
Carbon in the air is made available to living things, is used by them, and is then returned to the air.
Food-making organisms such as plants and algae need carbon to form carbohydrates, which are essential for growth.
They absorb carbon dioxide from the air
The carbon dioxide is combined with water to form carbohydrates.
Other living things, such as animals, need carbohydrates for energy
Small amounts of carbon dioxide are released into the air by the decomposition of dead organisms by certain bacteria and fungi.
The burning of fossil fuels, such as coal, also releases carbon dioxide into the atmosphere.
