EARTH’S RESOURCES Chapter 4

NONRENEWABLE RESOURCES

FO

SS

IL F

UELS

Hydrocarbon that’s used as source of energy

Coal Petroleum

& Natural Gas

Tar Sands Oil Shale

COAL Formed by heat and pressure transformed plant material As it develops it becomes harder and

releases more energy as it burns Peat →lignite (brown coal)→bituminous (soft

coal)→anthracite (hard coal) 70% of coal mined today used to generate

electricity

Problems with coal: Surface mining scars

the land (must restore land now)

Underground mining is costly to human life Collapsing roofs, gas

explosions, lung diseases

Safer now because of regulations

Air pollution – sulfur (S) becomes sulfur dioxide (SO2) when combined with oxygen (O2), then becomes sulfuric acid (H2SO4) when mixed with water

S + O2 → SO2

SO2 + H2O → H2SO4

PETROLEUM & NATURAL GAS

Formed from plant and animal remains that were buried in ancient seas, slow reactions occur b/w sediment and the remains, squeezed from rocks under water

Then rises toward surface b/c less dense than water

TAR SANDS

Mix of clay, sand, water, and tar called bitumen Similar to crude oils, but more viscous

Canada has the largest tar sand deposits Mined at the surface, then refined into oil by

removing impurities Requires about ½ the amount of energy to

purify as product yields Causes substantial land disturbance Requires lots of water which becomes

contaminated

OIL SHALE

Rock that contains waxy mixture of hydrocarbons called kerogen

Oil shale is mined and heated to vaporize kerogen which is then processed to remove the impurities

FORMATION OF MINERAL DEPOSITS

Ore – useful metallic mineral that can be mined at a profit.

Occurrence of valuable mineral resources are closely related to the rock cycle. Igneous Process – large bodies of

magma cools and heavy minerals crystallize first and settle to the bottom of the chamber

Hydrothermal Solutions Placer Deposits – eroded heavy

minerals settle quickly from moving water, while less dense particles continue to move. Particles are accumulated in stream bends, cracks and streambed irregularities.

Gold is the best known placer deposit First found in California in the 1800’s Prospectors can follow the placer deposits

upstream which can lead to original mineral deposits

NONMETALLIC MINERAL DEPOSITS

Counts for 94% of society’s resources

Extracted and processed for building and industrial minerals Building Materials: natural aggregate

(crushed stone, sand, & gravel) Industrial Materials: neutralize acidic

soils, ingredients in manufacture of steel Not as abundant Cost more b/c of travel More processing required to get proper

purity

ALTERNATE ENERGY SOURCES

RENEWABLE RESOURCESTakes only months, years, or decades to form or accumulate

SOLAR POWER - RENEWABLE

“fuel” is free and it’s non-polluting Equipment is expensive to install &

sunlight isn't always available 2 types:

Passive – doesn’t require equipment Active - requires equipment

Uses uranium as ‘fuel’ Mined from the Earth, takes millions of years to form

NUCLEAR POWER

Uranium nucleus is bombarded with neutrons, causing the nucleus to split, releasing more neutrons which split another nuclei as well as heat. This creates a chain reaction. The heat released

drives a steam turbine which powers generators.

Controlled by inserting a neutron emitting rod into reactor to absorb neutrons

It is very expensive to build a SAFE plant

Hazard associated with the disposal of nuclear waste

Concern of possible accidents Chernobyl (1986 ) Three Mile Island (1979) Fukushima (2012)

http://www.youtube.com/watch?feature=player_embedded&v=mYvEA6OHdsw

WIND ENERGY Used for centuries for

ships and grains Wind turns the windmill

‘blades’; the turning powers the turbine which generates electricity via a generator

As long as the world turns we’ll have wind

Wind is not constant nor powerful in many places

Generates lots of noise large pieces of land are expensive

HYDROELECTRIC POWER Water held in a reservoir behind a dam is

stored energy Water travels through the dam to turn a

turbine; the turbine powers a generator

Dams do not last forever; sediment builds up behind the dam

Suitable sites to build a dam is limited Damages ecosystems Non-polluting

GEOTHERMAL ENERGY

Harnessed by tapping natural underground reservoirs of steam and hot water; turns turbines which generate electric power

Occur where subsurface temperatures are higher due to recent volcanic activity

Relatively clean energy Exhaustible – reservoirs can’t be recharged

and last between 10 & 15 years Only available in volcanic areas

TIDAL POWER Tidal power is

harnessed by constructing a dam across the mouth of a bay or an estuary in coastal areas

The strong in-and-out flow of tidal water drives turbines and electric generators.

Only feasible if there is a bay or estuary with a tidal range less than 8m

WATER, AIR, & LAND RESOURCESVital Resources

WATER RESOURCES

71% of Earth’s surface, mostly saltwater

Ocean: provides currents (climate, water cycle, and habitat for marine life)

Freshwater: need in order to survive Less than 1% of all

water is usable freshwater

Freshwater pollution Point Source Pollution

– comes from known and specific locations Factory pipes,

sewage treatment plant, leaking landfill, or storage tank

Nonpoint Source Pollution – pollution that does not have a specific point of origin Runoff (water that flows

over the land and then to freshwater other than ground water) Water washes from

parking lot Sediment from

construction Pesticides from fields Waste rock from coal

mines

PROTECTING WATER RESOURCES

1972 congress passed Clean Water Act (CWA) Requires industry to reduce or eliminate point

source pollution into surface water & increased number of sewage plants

36-62% increase in safe fishing and swimming areas

1974 Safe Drinking Water Act was passed Set a maximum level of pollutants in drinking

water Public water resources are cleaner today

AIR RESOURCES

Contains N, O, H2O vapor, & other gases

Ozone (O3) keeps us from harmful UV radiation

Greenhouse gases keeps us warm (CO2)

Pollution in the air – changes chemical composition of the atmosphere

I. SourcesA. Fossil Fuel combustion

1. Forms smog or acid rain & CO2

2. Global warming(unnatural warming of lower atmosphere) causes glaciers to melt, increase in sea level, flooding of coastal plains

B. Chlorofluorocarbons (CFC’s) destroy ozone in stratosphere, increases UV rays which causes skin cancer and cataracts

II. Health Problems1. Short term problems include coughing;

wheezing; headache; and lung, eye, & throat irritation

2. Long term health effects include asthma, bronchitis, emphysema, and lung cancer

3. EPA estimates 200,000 deaths are associated with air pollution

PROTECTING THE AIR

1970 congress passed Clean Air Act – National Ambient Air Quality Standards (NAAQS) for 6 criteria in the air:

If too high, local government must fix

CO O3 Pb

SO2 Nitrogen oxides particulates

Today cars have control devices to reduce or eliminate products of combustionPower plants more likely to useless coal

STRATEGIES TO SAVE ENERGY

Use alternate energy sources that are renewable and nonpolluting

Electric or hybrid cars Energy conservation (burn less, less air

pollution)

LAND RESOURCES

Provides soil and forests, mineral, and energy resources

Damage to land resources: Mining Agriculture Forestry Landfills

Mining Essential b/c of our need for resources Tears up Earth’s surface and vegetation Causes soil erosion and creates pollution to

surrounding Soil and water ecosystems are destroyed

Agriculture: Heavy pumping (over long periods) for

irrigation depletes ground water and causes build up of salts in the soil

Then the soil becomes useless

Landfills Leak harmful wastes that get into soil and

ground water Need for reduction of waste and safer

disposal

Forestry: Must supply our paper and lumber Clear-cutting damages land

Causes soil erosion Destroys ecosystems & wildlife habitats 2nd growth forests don’t have same diversity

PROTECTING LAND RESOURCES

Can care for the land by preserving a lot of the resources including: Farming Landfills Forrests

Farming – use soil conservation practices to prevent the loss of topsoil and preserves soil fertility Contour plowing – plow across

contour of hillside Decreases runoff and washing of

topsoil Strip cropping – crops with

different nutrient requirements are planted in adjacent rows Preserves fertility of the soil

Use less pesticides and inorganic fertilizers to decrease chemicals in soil and crops Compost – partially decomposed

organic matter Integrated Pest Management (IPM) –

uses natural predators or mechanical process (vacuuming pests from leaves to decrease pests)

Sanitary Landfill replaces open dumps (1977) Plastic or clay liners that prevent leakage to soil or

groundwater Resource Conservation & Recovery Act (RCRA) – requires

companies to store, transport, and dispose of hazardous waste by strict guidelines

Comprehensive Environmental Response – mandates cleaning of abandoned hazardous waste sites that are a danger to the public or environment

Forests: selective cutting vs. clear cutting Selective cutting:

cut some not all trees b preserves topsoil

and habitat Clear cutting:

removes all trees Destroys habitats &

erosion of topsoil

PREVENTION Recycle: collection and processing of new

items that can be made into new products Less waste – cleaner, healthier future