Earth Systems And Resources

Chapter 8: Earth’s Systems & Resources

Description:

The earth is 4.5 Billion years old and has been through incredible changes. In this unit, we will look at the natural processes that change the earth over time, and how those changes can benefit and threaten humans. We will also examine Earth’s mineral, soil and water resources, as well as current issues regarding sustainable use of these resources and providing access for all people.

Unit Focus Question:

• How sustainable are humanity’s current practices regarding use of Earth’s soil, mineral and water resources, and what challenges remain to achieving sustainability in these areas?

Packet Contents:

Assignment	Due:
1.    Reading Questions 8A, Vocab List 8A, Video Questions 8A
2.    Reading Questions 8B, Vocab List 8B, Video Questions 8B

Chapter 8 Vocabulary List

Core	the innermost layer of earth
	Mantle	layer of earth above core, magma
Asthenosphere		layer of earth in outer part of mantle, semi molten rock
	Lithosphere	outermost layer of earth, mantle and crust
Crust		outermost layer of the lithosphere
	Hot spots	place where molten material reaches the lithosphere
Tectonic plates		plates that shift under earths surface
	Subduction	one plate going under another
Divergent boundary		where tectonic plates move away from each other
	Convergent boundary	where tectonic plates move toward each other
Transform boundary		where tectonic plates move past each other
	Fault zones	rock where a fault has occurred
Earthquake		shaking of earth's surface when potential energy  is released and earths
	crust moves

Richter scale	scale to measure the magnitude of an earthquake
	Minerals	solid chemical that forms under certain temperatures and pressures
Igneous rocks		rock formed by magma
	Sedimentary rocks	rock formed when sediments are compressed
Metamorphic rocks		rock formed when in high temperature and pressure
	Physical weathering	mechanical breakdown of rocks and minerals
Chemical weathering		break down of rocks and minerals by chemical reaction
	Erosion	physical removal of rock fragments
Deposition		accumulation or depositing of eroded material
	Soil	mix of geologic and organic components that form a dynamic membrane
around earths surface
Parent material	rock underlying soil, where soil is derived
	Topography	lines on a map that indicate distance from sea level
O horizon		organic detritus in various stages of decomposition
	A horizon	top layer of soil. organic and mineral material
E horizon		under O or A horizon, zone of leaching
	B horizon	mineral material with very little organic material
C horizon		least weathered, beneath the B horizon, like parent material
	Soil texture	percentage of clay, silt, and sand in a soil
CEC of a soil		number of exchangeable cations per dry weight that soil is capable of
	holding
Base saturation	proportion of soil basses to soil acids, percent
	Soil degradation	loss of soils ability to support plant life
Ores		concentrated accumulation of minerals where valuable material can be
	extracted
Metals	element with properties that allow it to conduct electricity and heat
	energy and other important features
Known reserves	fossil fuel energy source
	Strip mining	removal of strips of soil and rock to expose ore
Tailings		unwanted waste materials created during mining
	Open-pit mining	surface mining technique by removing from an open pit or borrow
Subsurface mining		mining  technique used when desired resource is more than 100 m
	below
SMRCA law	regulates environmental effects of coal mining

Reading Questions 8A

• Are Hybrid Electric Vehicles as Environmentally Friendly as We Think They Are? The availability of Earth’s resources was determined when the planet was formed.
• Earth is dynamic and constantly changing.
• The rock cycle recycles scarce minerals and elements.

1. Even though electric and hybrid vehicles reduce fossil fuel consumption, they still have a significant environmental impact. Explain why, and describe some of these impacts.

The cars are made out of scarce metals and the metal must is shipped over from other countries since they’re not mined in the U.S. Also the mining that is done to get the metals is very damaging to the environment plus they still use up a form of energy that was at one point most likely burned coal.

2. What explains the distribution of heavy and light elements within Earth’s volume? Where are each generally located, and how did they wind up there?

When the earth was forming the heavier elements sank to the center of the earth while the lighter elements floated to the surface. Heavier elements are located closer to the center of the earth and lighter elements are located near the earths surface.

3. The inside of the Earth is characterized by vertical zonation . Briefly describe each of Earth’s layers:

                Crust – outermost layer of the lithosphere, we walk on it               

                Mantle – layer of earth above core, magma         

                Core – the innermost layer of earth, ball of iron 

4. What is the connection between the heat at the Earth’s core and the movement of its tectonic plates?

The heat from the earths core causes convection currents which causes the movement of the tectonic plates

5. What evidence led Alfred Wegner to propose the theory of plate tectonics in 1912?

He saw identical rock formations on both sides of the Atlantic ocean 

6. How do the properties of oceanic crust rock and continental crust rock differ?

Oceanic –  part of earth's lithosphere that surfaces in the               ocean basin, heavy and dense Continental – layer of igneous, sedimentary, and metamorphic rocks which      forms continents,           relatively light

7. Suppose a single continent is breaking apart due to divergent plate boundary. One piece of the continent is moving north towards the polar regions and one piece of the continent is moving south towards the tropics. What effect do you think this process would have on biodiversity?

I think that the continent would be split in the middle between North and South by a ridge or river causing the species to grow differently on either side,ultimately the Northern part of the continent would have less species density because its colder then the tropics

8. Why do the Hawaiian Islands form an “arc”, with the oldest islands at one end and the youngest islands at the other end?

the Islands were created by a volcano that was created by two tectonic plates, as the volcano released magma islands were formed, the whole time the tectonic plates continued to move slowly carrying the islands away from the hot spot

9. At a convergent plate boundary where oceanic crust is meeting continental crust, what will happen?

At a convergent plate boundary where oceanic crust meets continental crust a long coastal mountain range will form when the oceanic plate slides under the continental plate lifting the continental plate

10. What types of tectonic plate movements can cause earthquakes?

Plates that move past each other on a transform plate boundary can cause earthquakes.

11. How much stronger is an earthquake that registers as an 8.0 on the Richter scale than an earthquake measuring 4.0?

An 8.0 earthquake is 100,000 times stronger than a 4.0 earthquake on the Richter scale each number high is 10 times stronger

12. Why are seismic activity and volcanic activity often located in the same places?

Volcanos are often located on a fault line where two plates meet

13. What is the relationship between minerals, elements and rocks?

minerals are made up of a single element and rocks are made up of minerals

14. Does the rock cycle proceed in any particular order when transformations from one type of rock to the next occur? Explain.

Igneous rocks and sedimentary rocks form on their own but metamorphic rocks can form from pre existing igneous and sedimentary rocks so there really isn't a particular order in which they form.

15. How are each of the 3 rock types formed?
    1. Igneous – rock made by magma
    2. Metamorphic – rock formed under high temperatures and pressure
    3. Sedimentary – rock formed when sediment is compressed

16. What is the difference between physical and chemical weathering?

physical weathering is the mechanical break down of rocks and minerals, like rain, while chemical weathering is   the breakdown of rocks and minerals by chemical reaction like plants.

17. What types of processes or forces usually cause erosion?

processes such as weathering, physical and chemical weathering cause erosion, it is also caused by the forces of wind, water, and ice as well as lack of plants because plant roots help hold together soil

18. Why are weathering and erosion important to the rock cycle?

weathering and erosion are important to the rock cycle because they help recycle minerals, chemicals and other elements back into the crust and just mix up the soil.

Reading Questions 8B

• Soil links the rock cycle to the biosphere.
• The uneven distribution of mineral resources has social and environmental consequences. Working Towards Sustainability: Mine Reclamation and Biodiversity

1. How is soil formed both “from above” and “from below”?

the breakdown of rocks and primary minerals by weathering provides raw material for sol from below. the decomposition of organic matter from organisms and their waste contributes to soil formation from above.

2. What effect does climate have on soil formation? How would you expect this to create differences between Boreal Forests and Tropical Rain Forests?

when soil is in cold/ freezing weather there is little to no decomposition, soil in high altitudes are composed primarily of organic matter that is undecomposed. while soil in tropical temperatures have an acceleration of soil formation because of the weathering of rocks , leaching of nutrients and decomposition of animals, climate also has an indirect effect on soil by influencing the types of vegetation that can grow in the area changing the roots. Boreal forests are colder so the roots of tree must run deep to provide the nutrients while a tropical rain forest is hot and humid so the decomposition of animals is fast allowing for small plants and small roots.

3. What role do organisms play in soil formation and development?

plants remove nutrients from soil but speed up chemical weathering, animals such as worms and gophers tunnel and mix dirt distributing organic and mineral matter uniformly, 

4. Why do soils develop different horizons? What separates one horizon from another?

horizons are classified by their properties and their functions, they depend on climate, vegetation and parent material; depth of the soil is what can separate one horizon from another

5. Soils contain different blends of sand, silt and clay. Why is a balance needed between all 3 to promote ideal plant growth? (What would be bad about a sand-heavy or clay-heavy soil?)

a balance is needed in order for the soil to retain water and let water drain out of it, if soil was sand-heavy then water would easily drain out of it or if soil was clay-heavy then water could not filer through it and plant roots would struggle.

6. What type of soil particles would be best to line a pit that is to be filled with hazardous chemicals?

a soil that would be good to line a pit containing hazardous chemicals would be clay because it won't let the chemicals pass through it.

7. What occurs during adsorption in a soil?

during absorption clay particles are positively charged and attract minerals on the surface “cations” which are negatively charged. 

8. Can soils have both high CEC and high porosity? Explain why or why not.

no because CEC means having a lot of clay which then provides minerals to plants however having high CEC means more clay so if you have a lot of clay then a soil can not be porse.

9. How are the CEC of a soil and its base saturation related?

Base saturation is the measure of how much bases to acids there is in the soil represented as a percentage, a high base saturation promotes plant growth as well as a good CEC.

10. What types of organisms dominate the biological component of soil?

fungi, bacteria and protozoans

11. Why is compaction bad for soil?

compact soil lacks the ability to retain water,reduces the amount of vegetation in the soil which leads to an increase in erosion. 

12. Which two elements make up approximately 75% of the Earth’s crust?

silicon and oxygen

13. What is the difference between an ore vein and a disseminated deposit? Which ones are easier to mine?

ore veins are small areas with a high concentration of a mineral or metal while disseminating deposits are much larger areas with a smaller concentration. ore veins are easier to mine because its in a small area and its closely packed together.

14. What are the 3 techniques used for surface mining, and what are the environmental dangers of each?

1.strip mining: removal of strips of soil to expose ores, deep. This can cause the ph of the soil to increase as the miners have to pump water out of the mine 

2. Open-Pit Mining: large holes in the ground. the air quality is bad as workers breath in a lot of dust, habitat destruction.

3.Mountaintop removal: miners use explosives and large machinery to literally remove the top of a mountain to extract minerals. the spoils of this are dumped in streams or rivers polluting the water.

15. In general, why does the impact of extracting deposits of a certain mineral resource increase over time?

extracting deposits of a certain resource increase over time because of a growing demand for cheaper resources, so as one mine closes two more have to open to met the demand.

16. What legal requirements did SMRA (the Surface Mining Control and Reclamation Act of 1977) introduce?

land be minimally disturbed during the mining process and reclaimed after mining is completed meaning the land is restored.