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Chapter 1

Philosophy and Fundamental Concepts

Dr. Joao Santos

Chapter 1

Philosophy and Fundamental Concepts

Dr. Joao Santos

© 2012 Pearson Education, Inc.

What is Environmental Geology? (1)

• Geology is the science of processes related to the composition, structure, and history of Earth and its life. Geology is an interdisciplinary science, relying on aspects of chemistry (composition of Earth’s materials), physics (natural laws), and biology (understanding of life forms).

• Environmental Geology is applied geology. Specifically, it is the use of geologic knowledge to help society solve conflicts in land use, to minimize environmental degradation, and to maximize the beneficial results of using our natural and modified environments.

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What is Environmental Geology? (2)

The application of geology to these problems includes the study of the following:

• Earth materials, such as minerals, rocks, and soils, to determine how they form, their potential use as resources or waste disposal sites, and their effects on human health.

• Natural hazards, such as floods, landslides, earthquakes, and volcanic activity, in order to minimize loss of life and property.

• Land for site selection, land-use planning, and environmental impact analysis.

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What is Environmental Geology? (3)

• Hydrological processes of groundwater and surface water to evaluate water resources and water pollution problems.

• Geological processes, such as deposition of sediments on the ocean floor, the formation of mountains, and the movement of water on and below the surface of Earth, to evaluate local, regional, and global change.

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Earth History (1)

• Inception: 4.6 billion yrs

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Our Solar System (1)

Solar flare

• Solar System Formation: Nebular theory

– Planets formed ~ 4.6 billion years ago

– Solar system condensed from a solar nebula (usually remnants of a supernova)

• Because of gravity most material collected at center as the hot protosun.

• Other material formed a flattened rotating disc.

– Matter in the disc cooled and collided forming planetesimals

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Our Solar System (2)

Solar flare

Solar System Formation: Nebular theory

• As the protoplanets formed, the materials that compose them separated.

– Dense metallic elements (iron and nickel) sank toward their centers forming their cores

– Lighter elements (silicate minerals, oxygen, hydrogen) migrated toward their surfaces forming their mantles and crusts

– Process called chemical differentiation

• Due to their surface gravities (a consequence of their mass), Venus and Earth retained atmospheric gases forming considerable atmospheres.

• Due to frigid temperatures in the outer solar system, the Jovian planets collected ice around their cores. As their cores grew, their surface gravity increased allowing them to collect large amounts of gas (hydrogen and helium) that were available in the outer solar system.

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Our Solar System (3) Solar System Formation: Nebular theory

• When stars form they are surrounded by a rotating disk of cosmic debris (Nebular theory).

• Gravity pulls debris together to form planets that revolve in a consistent direction around star.

− Heavier, rocky planets form closer to the star

− Lighter, gas-rich planets form farther from the star

• Potentially thousands or millions of extra-solar planets revolve around other stars.

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Our Solar System (4)

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Earth History (2)

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Fundamental Concepts of Environmental Geology

• Five fundamental concepts

– Population growth

– Sustainability

– System and change

– Hazardous Earth processes

– Scientific knowledge and values

• Other important concepts in environmental geology

– Finite resources, obligation to future

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Human Population Growth (1)

• Number one environmental problem: Nearly 7 billion by the year 2010

• “Population bomb?” Exponential growth

• Exponential growth

– Growth rate (G): Measured as a percentage

– Doubling time (D): D = 70/G

• Above Earth’s comfortable carrying capacity: Use more resources, need more land space, generate more waste

• Earth as the only suitable habitat in the foreseeable future

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Human Population Growth (2)

• Population Bomb: About to Explode?

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Human Population Growth (3)

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Human Population Growth (4)

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Human Population Growth (5)

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Human Population Growth (6)

Uneven growing pace and distribution

• By 2050, 3 billions more people

• Almost all of the growth in developing countries

• No easy answer to the population problems

• Education is paramount, especially woman’s education. As people become more educated, the population growth rate tends to decrease

• Good news: The rate of population growth is decreasing

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Sustainability (1)

Sustainability: The environmental objective

• An evolving concept

• Expectation and reality

• Criteria variations in space and over time

• Is a long-term concept and has long-term implications

• Requiring careful resources allocation, large- scale development of new technology for resource use, recycling, and waste disposal

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Sustainability (2)

Measuring sustainability

• Use and consumption of non-renewable resources

• Natural replenishment and renewable rates

• Global consumption versus replenishment of resources

• Development and improvement of human environment versus viable environment

• Not lead to environmental crisis

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Sustainability: The Death of Aral Sea (3)

• Once a prosperous vacation spot in 1960

• Water diversion for agriculture

• Dying sea surrounded by salt flats

• Largely irreversible

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Sustainability: The Death of Aral Sea (4)

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Earth’s Systems and Changes (1)

• System conditions: Open versus closed systems

• System input-output analysis

• System changes: Types of changes, rates of changes, scales of changes, etc.

• Rates of change: Average residence time

– T = S/F

(T: residence time, S: total size of stock, F: average rate of transfer)

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Earth’s Systems and Changes (2)

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Earth’s Systems and Changes (3)

• Earth: A dynamic system

• Four interconnected subsystems: Lithosphere, atmosphere, hydrosphere, and biosphere

• Four subsystems are interconnected and interdependent

• Present human activity key to understanding the future

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Predicting Future Changes

• Uniformitarianism (James Hutton, 1785)

– The present is the key to the past

– The present is the key to the future

– Changes of frequency and magnitude: Geological processes and human activities

• Environmental unity: Chain of actions and reactions

• Earth system

– Gaia hypothesis: Earth is a living organism

– Complex and interrelated subsystems

– Global perspective on environment

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Hazardous Earth Processes

Hazardous Earth processes and risk statistics for the past two decades

• Annual loss of life: About 150,000

• Financial loss: > $20 billion

• Millions of life loss during the past 20 years, particularly catastrophic from a major natural disaster in a developing country (2003 Iran quake, ~30,000 people, 2004 Asia tsunamis, ~300,000)

• More property damage occurs in a more developed country

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Scientific Knowledge and Values (1)

• Science: Accumulated knowledge

• Knowledge: Basis for decision making

• Scientific methods: Formulate possible solutions to environmental problems

• Scientific design: Structure more suitable for certain environmental settings

• Scientific info: Public awareness and environmental regulations

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Scientific Knowledge and Values (2)

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Solving Environmental Problems

• Difficult processes

• Environmental problems tend to be complex

• Rapid changes, slow recognition, slower actions

• Some changes are of irreversible nature

• Environmental policy links to environmental economics in infancy

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End of Chapter 1