APES CHAPTER 5.9-5.10

Mining

the process of extracting mineral resources from the Earth (iron, gold, limestone, coal, diamonds etc.)

• concentrations of naturally recurring resources can be extracted and processed

• with ores depleted operations are forced to mine lower grade ores leading to pollution as minerals are finite

Overburden-

large portions of soil and rock needed to be removed to access the ore and mineral resources underneath

Two Types of Mining Techniques-

surface and subsurface mining

Types of Surface Mining-

• strip mining

• open-pit mining

• mountaintop removal

• placer mining

Surface Mning-

removal of minerals or ore deposits close to the surface og the Earth

Subsurface Mining-

used when the resource is more than 100m below Earth’s surface

Strip Mining-

removal of strips of soil and rock to expose the underlying ore and is used when ores run parallel to the Earth’s surface which is often the case for deposits of sedimentary materials

Mine Tailings-

unwanted waste material created during mining including mineral and other residues that are left behind after the desired metal or ore is removed

Acid Mine Drainage-

water that passes through mine tailing. The water reacts with the tailings becoming acidic

Open-pit Mining-

a mining technique that creates large hole/pit in the ground and is used when the resource is close to the surface but extends underneath the surface both vertically and horizontally (copper)

Mountaintop Removal-

an entire mountaintop is removed using explosives; the tailing is deposited at lower elevations near rivers and streams which can block or change the flow of river

Placer Mining-

the process of looking for metals and precious stones in river sediments separating heavier metals and stone from sand and mud which can contaminate rivers (some parts use mercury)

Subsurface Mining-

mining that occurs when resources (coal, gold, & diamonds) are more than 100 m (328 ft) below the surface of the Earth beginning/ horizontal tunnel from which vertical shafts are drilled (uses elevators); more expensive than surface mining

Environmental impact of Mining-

• mining requires cpnstruction of roads which can fragment habitats, soil erosion, and damage to waterways

• all mining produces tailings which can contaminate land and water

Mining Law of 1972 aka General Mining Act-

regulates mining of silver, copper, and gold ores, as well as fuels, including natural gas and oil on federal lands and allows companies and individuals to recover ores from federal land (contains few provisions about environmental protections

Surface Mining Control and Reclamation Act of 1977-

regulates surface mining of coal and mandates that land must be minimally disturbed during mining process and be reclaimed after mining is completed

Mine Reclamation-

the combined process by which adverse environmental effects of surface mining are minimized and mines lands are returned to a beneficial end use

The process of reclamation involves…

1. Re-contouring the land

2. Replacing topsoil

3. Replanting native vegetation or reseeding

4. Yearly monitoring to ensure success

Urban Area-

an area that contains more than 386 people per sqaure km (1000 people per square mile)

Urbanization-

creation or growth of urban areas, or cities, and their surrounding developed land

• movement of people from rural areas to cities

• people move to urban areas for various reasons including job opportunities, social benefits and education opportunities

• more than half the word’s population lives in urban areas (80% in the U.S)

Positive Impacts of Urbanization-

• reduced commute distances saving gas and CO₂ emissions due to public transportation and nearby shopping. Can reduce per capita (person) carbon footprint

• in developed countries, density pushes residents to live in smaller homes, requiring less energy. Can reduce per capita carbon footprint

• may reduce the amount of people relying on destructive practices such as slash-and-burn agriculture

Negative Impacts of Urbanization-

• as urban areas expand, infrastructure needs to be built to support the growing population. This includes housing, roads, water, and sewer lines, transportation facilities, schools, etc.

• while urban areas as a whole produce greater amounts of solid waste, pollution and CO₂ emissions than suburban and rural areas (tend to have smaller per capita ecological footprints)

• urban heat islands

• carbon cycle is affected due to increased CO₂ levels in the atmosphere from more vehicles, office building, manufacturing companies, etc.

• impacts water cycle- instead of infiltrating the ground, water that hits concrete flows as runoff which can overwhelm city drainage systems during heavy rains leading to flooding

• saltwater intrusion (invades freshwater making unusable for irrigation, drinking, etc.)

• may fragment natural habitats which in turn can decrease biodiversity and increase competition among species

Urban Heat Islands-

a warmer microclimate around cities due to infrastructure that retains heat and fewer green spaces (as natural land is paved with asphalt or concrete its albedo decreased and surfaces absorb more solar energy)

Saltwater Intrusion-

the movement of ocean saltwater into freshwater aquifers due to changes in density and pressure gradients

Urban Sprawl-

urbanized areas that spread into rural areas, removing clear boundaries b/w the two

Suburb-

an area surrounding a metropolitan center, with a completely low population density

Exurb-

an area similar to a suburb, but unconnected to any central city or densely populated area

Four Main Causes of Urban Sprawl in the U.S. are:

• Automobiles and Highway Construction

• Lower Living Costs'

• Urban Blight

• Government Policies

Four Main Causes of Urban Sprawl in the U.S. (Automobile and Highway Construction)-

makes commuting easier

Four Main Causes of Urban Sprawl in the U.S. (Lower Living Costs)-

creation of suburbs due to land being readily available, cheaper real estate, lower taxes

Four Main Causes of Urban Sprawl in the U.S. (Urban Blight)-

the degradation of the built and social environments of the city that often accompanies and accelerates migration to the suburbs (opposite is true in developing countries less jobs & poverty=converging to cities)

Four Main Causes of Urban Sprawl in the U.S. (Government Policies)-

zoning (residential tool used to separate industry and business from residential neighborhoods)

Impacts of Urban Sprawl-

1. increase dependency on vehicles→ CO₂ production→ global warming

2. greater water pollution

3. loss of agriculture capacity

4. destruction of wildlife habitat→ loss of biodiversity

5. increased infrastructure like roads to support traffic and increased traffic jams and greenhouse gas emissions

6. increases impermeable surfaces→ flooding