BIO 127 Lecture Exam #4

Geology

Study of Earth’s composition

Core

Center of Earth

Inner = solid iron

outer = molten iron

Mantle

Surrounds core

Magma (hot/liquid rock)

Lithosphere

Consists of upper mantle + crust

Crust

Outermost layer

Thin + brittle

Plate tectonics shape Earth’s geography

Earth has 15 major tectonic plates

Movement of these plates influences climate and evolution

Pangea

All continents were combined and landlocked together

Plate tectonics

Movement of the tectonic plates

Divergent plate boundaries

Moving apart in opposite directions

Ridges

Transform plate boundaries

Slip past each other

Earthquakes

Convergent plate boundaries

Move toward each other

Trench

Mountains

Subduction

1 plate slips under the other

Rock

Aggregation of minerals

All rocks can melt

all rocks will weather

Types of rock determine soil characteristics

Mineral

Elements of crystal structure

Magma

Hot molten (liquid rock)

Lava

Magma that has escaped at Earths surface

Igneous Rock

Solidified Magma

Sediments

Rock particles

Sedimentary Rock

Sediments glued together via lithification

Lithification

Minerals glue sediments together

Metamorphic Rock

Rock that changes form

Earthquake

Sudden release of pressure at transfer plate boundaries

Volcanoes

Release of lava

Lava can exit in rift valleys, ocean ridges, subduction zones, or hotspots (holes in crust)

Consequences of Ash blocking sunlight?

Cooling

Impact on agriculture

Sulfur emissions lead to sulfuric acid consequences?

Acid rain

Landslides

Sudden movement of soil

Natural process worsened by humans

Tsunamis

Sudden movement of large quantity of water

Damages coral reefs, coastal forests, and wetlands

Mining

Extraction of any natural resource

Ore

Rock aggregation containing metal

Metal

Lustrous elements capable of conducting electricity

Valuable metals include

Copper

Iron

Lead

Gold

Aluminum

Tantalum

Smelting

Heat metal + combine w/another metal or non metal material

Alloy

Ex. Steel is an alloy of iron and carbon

Strip Mining

Resource occurs: shallow deposits

Extraction involves: Strip/remove layers of Earth on top of deposit

Impact: Loss of habitat

Acid drainage

Sulfur + Oxygen = Sulfuric acid

Subsurface mining

Resource: Concentrated pockets underground

Extraction involves: Creation of tunnels/shafts

Impact: Human health concerns

Open pit mining

Resource occurs: Deep underground, widespread

Extraction involves: Large holes/pits

Impact: Loss of habitat/acid drainage

Placer mining

Resource occurs: In a riverbed

Extraction involves: Sifting with water

Impact: Polluting river + damage to riverbed

Mountain removal mining

Resource occurs: Located at the top of mountain

Extraction: Explosives

Impact: Polluting valleys on either side of the mountain

Solution mining

Resources occur: Deep concentrated pocket

Extraction involves: fluids (chemicals) are pumped into pocket

Impact: Least damage to surface area

Reclamation

Governments in developed countries require companies to reclaim (restore) surface-mined sites

The U.S. Surface Mining Control and Reclamation Act (1977)

Recycling Minerals

35% of metals are currently recycled from U.S. solid waste

Recycling decreases energy use and lowers greenhouse gases

Nonrenewable resources 

A non-renewable resource is a natural resource that cannot be readily replaced by natural means at a pace quick enough to keep up with consumption.

Renewable resources

Renewable energy sources, such as biomass, geothermal resources, sunlight, water, and wind, are natural resources that can be converted into these types of clean, usable energy: Bioenergy.

Fossil Fuels

Combustible material created from the remains of one-living (aka DEAD) living organisms 

Fossil Fuel uses

Coal used primarily for electricity 

Natural gas used for electricity, heat, cooking 

Petroleum, used for vehicles or household needs

Expanding our use of fossil fuels 

Mountaintop mining for coal 

Secondary extraction from existing wells 

Hydraulic fracturing for oil and gas 

Offshore drilling in deep waters 

Exploring new “unconventional” fossil fuel sources (oil, shale, oil sands) 

Environmental issues

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To extract oil sands, vast areas of forest are cleared and enormous pits are dug 

Hydraulic fracturing aka fracking (Using pressurized water/chemicals to crack shale rock and release previously inaccessible fossil fuels (Ex. Natural gas) 

Energy is not free 

Substantial input of energy is required 

Energy returned on investment (EROI) = ratio that determines if extraction of a fossil fuel is “worthwhile” by comparing energy returned (can be used) versus energy invested (needed to extract) 

Proven recoverable resource

 The quality of fossil fuels that is both technologically and economically feasible to extract

Reserves-to-production ratio (R/P) 

Ratio of how much fossil fuels remain versus production rate 

Current estimate of oil reserves is 1.7 trillion barrels, and the rate of production is 33.6 billion per year 

How many years of oil do we have left 

Peak oil

extraction rates peak and production rates 

Nuclear energy

Energy acquired from atomic nuclei

Renewable energy offers advantages 

less emissions, limitless (inexhaustible)

Policy and investment needed to transition

Market prices will fall as usage goes up (subsidies needed)

Solar energy

Energy from the sun

Passive solar energy collection 

collects heat as the sun shines through south-facing windows and retains it in materials that store heat, known as thermal mass

Active solar energy collection

Use solar energy to heat a fluid -- either liquid or air -- and then transfer the solar heat directly to the interior space or to a storage system for later use

Solar energy is expanding

Due to the lack of government investment, solar energy contributed only 0.1 of energy used 

Wind Power

Energy from the movement of air 

Wind turbines 

Offshore sites and mountainous regions are most useful 

Wind Speeds are 20% greater over water than over land, with less air turbulence over water 

Geothermal energy 

Energy from the heat underground

Tidal energy

Energy from movement of tides (vertical)

Hydroelectric power

The use of water to generate electricity 

Bioenergy 

Energy from biomass (organic, carbon-based material from living things 

Biopower 

Bioenergy used for electricity generation

Waste products from logging, sawmills, pulp mills, and paper mills can be used as fuel 

Biofuels

Bioenergy for fueling vehicles 

Ethanol 

Biodiesel 

Advantages: Less vehicle emissions, Nearly identical fuel economy, Cost effective, Non-toxic and biodegradable

Novel Biofuels are being developed

Algae biofuel 

Cellulosic ethanol 

Hydrogen and fuel cells 

Hydrogen releases energy when it combines with oxygen to produce water (hydrogen gas does not exist freely on earth) 

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Waste

Unwanted material generated by humans

Municipal solid waste

Industrial solid waste

Hazardous waste

Three components of waste management

Minimize waste generated (source reduction)

Recover, re-use, recycle

Dispose of effectively and safely

Waste stream

Flow of waste from source to disposal

Municipal solid waste

Non-liquid waste generated by homes / small businesses “trash”

Affluence and waste

Affluent nations have higher rates of consumption and waste production

Reuse

To use an item more than once

Recycling

To extract raw materials from an item + use them to construct a new product

Recycling has grown rapidly

Rates increased from 6.4% to 25.7% since 1960

Composting

To allow biodegradable waste items to compose

Home composting

Municipal composting

Sanitary Landfills

Disposal location for municipal solid waste

Resource Conservation and Recovery Act

Located away from wetlands

Lined with plastic

Layers of impermeable clay

Leachate System (maintained 30 years after closure)

Leachate

Rainfall travels through waste

NIMBY (Not In My Backyard)

Affluent communities have the money + political power to prevent landfills in their neighborhood

Incineration

burning of MSW

Landfill Gas

Similar to natural gas

Created at landfill

Industrial Solid Waste

Non-liquid waste generated by industry

Industrial Solid Waste landfills

Monitored by state/local governments with less strict regulations than MSW (no leachate system, no liners required)

Industrial Ecology

Involves redesigning industrial systems to reduce resource inputs while maximizing physical and economic efficiency

Hazardous Waste

A liquid, solid, or gas that is either:

Ignitable

Corrosive

Reactive

Toxic

Industry

Produces the largest amount of hazardous waste

Households:

The largest source of unregulated hazardous waste

Disposal Methods for Hazardous Waste

Must be tracked “cradle to grave”

Hazardous waste landfills

Strictest regulations (several liners. leachate system, far from aquifers)

Surface Impoundments

Liquid hazardous waste stored in shallow depression + allowed to evaporate

Deep-Well Injection

Pumping liquid hazardous waste below aquifer

E-waste has grown

Waste from electronics

Treated as hazardous waste due to presence of flame retardants and heavy metals

Brownfields

Sites contaminated by hazardous waste development is halted

Comprehensive Environmental Response Compensation and Liability Act (CERCLA) (1980)

Established a hazardous waste site cleanup program called the Superfund

Operates under “polluter pays principle”

Fewer cleanups being completed due to cost, difficulty and length of time (25 million, 15 years)

Classical Economics

The parties involved in an economic exchange decide whether or not exchange is worthwhile or not

Neoclassical economics

Economic exchange is determined by supply and demand

Environmental Consequences of Neoclassical economics

Capitalist market systems operate with neoclassical economics 

Assumptions of neoclassical economics contribute to environmental degradation