earth as a system
DESCRIPTION
Earth as a system. Open & Closed Systems. s ystem – defined as a set of parts that work together. open system – parts can be added or lost closed system – all parts exist in precise amounts and nothing can be added or lost . Open System Examples. Hockey Teams. - PowerPoint PPT PresentationTRANSCRIPT
Earth as a system
Open & Closed Systems
system – defined as a set of parts that work together.
open system – parts can be added or lost
closed system – all parts exist in precise amounts and nothing can be added or lost
Open System Examples
The Human Body
Hockey Teams
Closed system example
A closed jar
Earth – Closed & Open
Closed- all important things such as water, gases, and nutrients exist in limited amounts. They get recycled over and over again. If we use up or deplete these ingredients, we risk upsetting the balance of the entire system.
Open – Heat, radiation, spaceships, debris from space. (incoming and outgoing energy) (shortwave and longwave)
4 Spheres1. Atmosphere – all gases
If earth was the size of a beach ball, theatmospherewould be as thinas a piece of paper.
Atmosphere Processes
Constant movement of air and water through atmosphere and oceans
Drives Earth’s Weather and Climate
Unequal heating of Earth’s land forms and oceans
Earth’s rotation on its axis and its orbital revolution around the sun
Single-cell model
Assumptions: - earth’s surface is uniformly covered in water- The sun is always directly over the equator
(winds will not shift seasonally)- The earth does not rotate (only have to deal
with pressure force)
Single-cell model
Response to the unequal heating of the earth
Coriolis Effect
Three-cell model
Allow earth to spin.
Prevailing winds – Global Patterns -
(January)Add tilt – seasons have an effect! Example: India (cold dry air gets pushed down from the Himalayan mountains) – Result - drought
Prevailing winds – Global Patterns - (July)
Example: Wind patterns reversed – now blow warm moist air from Indian ocean Result: torrential rains and flooding (monsoon season)
4 Spheres2. Biosphere – all living things (Vladmir Vernadsky) - Russian- Divided up into separate
but interdependent units called ecosystems.
- The continuation of life within the biosphere depends on the constant recycling of a number of chemical ingredients called nutrients.
Nutrient Cycles
1) Oxygen Cycle2) Nitrogen Cycle3) Carbon Cycle4) Water Cycle
The Carbon CycleAtmosphere
Plants, Animals, and Soil
Atmosphere
** A very important cycle, even if more than 99 percent of the Earth’s carbon supply is stored in sedimentary rock and in the oceans.
Carbon Cycle
Photosynthesis! Deforestation!- Release of carbon dioxide- http://www.youtube.com/wat
ch?v=7NpTBQFwC8U- http://www.youtube.com/wat
ch?v=unv92gQ4ZAo
Oxygen Cycle
Majority of oxygen in the atmosphere is produced by the respiration of plants. (90% by algae in the world’s oceans)
Plants release this oxygen when they produce carbohydrates during photosynthesis.
Reacts with carbon released by decomposing or burning vegetation or fossil fuels to form CO2
Breathed in by humans & animals and out as CO2
Taken back by plant roots – reverses process of photosynthesis
Nitrogen Cycle
Most plentiful element in Earth’s atmosphere (78%)
Nitrogen – (“Free State”)
Ammonia & Nitrates
Microscopic bacteria living on the roots of certain plants called legumes (alfalfa, peas, and beans)
Proteins
Plant converts
“Fix” free nitrogen
New Proteins – Amino Acids
Animals eat plants and use these proteins and other nitrogen compounds to build amino acids
Nitrogen Cycle
Ammonia & Nitrates
Animals produce waste and die – bacteria begins decomposing amino acid proteins
New Proteins – Amino Acids
Release Nitrogen back into atmosphere in its “free state”
Reabsorbed by plant roots, carried by water to the oceans, or fixed again by bacteria in a reverse process
Denitrification
Deforestation and water cycle…
How is the water cycle affected when a forest is cut down?
4 Spheres3. Lithosphere – soils, rocks, minerals (Earth’s crust)
Rock Cycle (Pg. 55-56)
Igneous – granite
Sedimentary – sandstone and shale
Metamorphic – marble or slate
- Plates – segments of Earth’s crust which are being pushed apart or together in precise directions and constant speeds.
4 Spheres4. Hydrosphere– all water
Ocean currents
Are similar to the wind patterns Drag of wind on the surface of oceans – primary
cause of currents.Also affected by Coriolis effectHelp to restore energy balance (moving warm
water north and cooler water south) Influence the climate of surrounding areas
Gulf stream
Ocean currents
Tides
Cause – gravitational pull of the moon and sun
Ocean water “piles up” on the side of Earth facing the moon and on the far side of Earth directly opposite the moon. (far side is a result of the centrifugal force of Earth’s rotation) This is high tide. Perpendicular to the high tides are the low tides.
Importance of Tides
Move large amounts of sediment Marshes that become important feeding areas for
many types of fish , shellfish , and waterfowlHydroelectric powerBring Nutrients into coastal areas
Help sustain plant life, provide food for shrimp & crabs
Navigation and shipping Tidal surges could keep harbours clear of ice
buildups
Gaia Hypothesis
British biochemist James Lovelock He believed Earth can be viewed as as single
organism that in 4.6 billion years has developed into a self-regulating system. Ex: an overgrown forest cannot support new life.
Wildfires burn it down, creating room for new growth Gaia (goddess of the Earth) can adapt
Asteroid collisions Earth cannot be destroyed by humans Only concern: how Gaia reacts to the environmental
assault