Environmental Geology - Chapters 1,2,3,4

Environmental Geology Chapters 1-4

Average residence time

• amount of time it takes for the total stock or supply of material in a system to be cycled through the system

Carrying capacity

• Maximum number of a population of a species that may be maintained within a particular environment without degrading the ability of that environment to maintain that population in the future

Doubling time

• Time necessary for a quantity of whatever is being measure to double

Earth systems science

• Study of Earth as a system

Environmental crisis

• Refers to the hypothesis that environmental degradation has reached a crisis point as a result of human use of the environment

Environmental geology

• Aka Applied geology

• Uses geologic information which helps solve conflicts in land use, minimize environmental degradation, and maximize beneficial results of our natural and changed environments (solve environmental problems)

Environmental unity

• Principle of environmental studies that states everything is connected to everything else

Exponential growth

• Compound growth in which a total amount or number increases at a certain percentage each year, and each year’s rate of growth is added to the total from he previous year

Gaia hypothesis

• Earth is an organism

• Life significantly affects Earth’s environment

• Life modifies the environment for the betterment of life

• Life deliberately or consciously controls the global environment

• Interdisciplinary thinking

Geological time

• Time extending from the beginning of Earth to present

  • Recorded in rocks and sediments that have been deposited and formed at various times

Geology

• science of processes related to the composition, structure, and history of Earth and its life

Growth rate

• Rate measured as a percentage by which something is changing

Hypothesis

• Statement intended to be a possible answer to a scientific question

Input-output analysis

• Type of system analysis in which rates of input and output are calculated and compared

Land ethic

• Affirms the right of all resources, including plants, animals, and earth materials

Law of faunal assemblages

• law of faunal succession

• Geological sciences that states that the fossils or organisms succeed one another in an order than may be recognized

  • Aka fossil content of sedimentary rock suggest rocks’ relative age

Precautionary principle

• Environment planning tool which advocates taking cost-effective, proactive steps to eliminate or reduce the consequences of an environmental problem even if the science is not completely worked out

Scientific method

• method by which scientists work

• Steps:

  • Ask questions

  • Field work

  • Refine the question

  • Hypothesis

  • Test hypothesis

  • Conclusion

    • if accepted more testing and can be a theory

    • if rejected new hypothesis

Sustainability

• Development or use of resources in such as way that future generations will have a fair share of Earth’s resources and inherit a quality environment

System

• Part of the universe that is isolated in thought or in fact for the purpose of studying or observing changes that occur under various imposed conditions

Theory

• Strong scientific statement

  • Hypothesis can be a theory after has been tested multiples times and not rejected

Uniformitarianism

• Present is the key to the past

Case Study: Island of Hispaniola

• Haiti vs. Dominican Republic

• Biophysical difference: rainfall, land use/cover

• Socioeconomic differences: History, population, and economic activities

• Haiti was not able to quickly rebuild after the 2010 earthquake

James Hutton

• 1785

• Earth as a superorganism

• “Father of"geology”

Origin of Earth systems:

• 1) Lithosphere

• 2) Atmosphere

• 3) Hydrosphere

• 4) Biosphere

What are the limited resources on Earth?

• energy, soil, freshwater, forest, ocean fisheries, rangelands

Inception of the Earth was how many years ago?

• 4.6 billion years ago

James Lovelock

• Created the Gaia Hypothesis

Case History: Endangered Trout in CA

• Rock types, structures, and groundwater important for understanding fish habitat

• Born in mountain streams and travel to the ocean (low summer flow)

• Eggs hatch in the gravel of the stream

Ecology

• Study of relationships between Living things and their environments

• Study of controls over the distribution, abundance, and health conditions of living things

Species

• Group of individuals capable of interbreeding

Population

• Group of the same species living in the same area

Community

• group of the population of different species living in the same area

Biota

• Organisms living in an area or region

• Example: producers, consumers and decomposers

Biosphere

Part of Earth where organisms exist and function

Indigenous species

• Found in the area where they evolved

Exotic species

• Brought into an area or a region by human purposely or accidentally

Invasive species

• Exotic species compete with indigenous species and may displace them

What are they 3 types of ecosystems?

• Natural Indigenous: Rarely exist on land and have been a result of completely natural evolutional processes

• Human modified: Almost all major ecosystems which have been modified for human use and interest

• Human constructed: Man-made ecosystems such as ponds, canals, and wastewater treatment pools

Natural Functions

• Processes responsible for producing clean water, air and diverse living matter

What are the direct functions of an ecosystem?

• Cycle of chemical elements (CO2, O)

• Flowing of energy and nutrients

• Removal of pollutants

Buffering Functions

• Providing protections from natural hazards (ex: wetlands against coastal flooding and erosion)

Biodiversity

• Number or abundance of species in an ecosystem or ecological community

Species richness

• Number of species

Species evenness

• Relative proportion of species

Species dominance

• One of the multiple species more common than others

Keystone species

• Exerting a stronger community effect disproportionate to their abundance

  • Example: Sharks, bears, elephants

How does geology affect an ecosystem?

• Change in topography

• Plate tectonics and ecosystem barrier

• Changes in climate

Yellowstone National Park (Wolves and Elk)

• Wolves were removed from Yellowstone in the 1960s - 1990s leading the elk to destroy vegetation near streams

• 1990s wolves were reintroduced and hunted elks which brought back vegetation and increased water quality

Categories of Keystone Species

• Keystone predators

• Keystone pray

• Keystone ecosystem engineers

• Keystone mutualist

• Keystone producers

Sea otters and kelp

• Urchins were destroying large abundance of the holdfast (root) of kelp

• Sea otters ate the urchins and allowed kelp forests to regrow

Ways to Increase Bidiversity?

• Presence of diverse habitat

• Favored geological environment

• Relatively constant environmental conditions

• Highly modified biological productive environment

Ways to reduce biodiversity?

• Extreme geological environment

• Fragmentation of ecosystem by land use transformation

• Intrusion of invasive exotic species

• Habitat simplification

Human activities exerting dominant community effects

• Dominate all ecosystems on Earth

• Massive land use transformation

• Global climate change

• Changes in biogeochemical cycles

  • O, Co2, energy, nutrients

• Rapid extinction of many species during the last 2000 years

Seawalls

• Structure made of concrete, large boulders, or wood parallel to the shore with the objective of stopping coastal erosion

  • Ex: Galveston

Total Footprint

• Product of the footprint per person times the total number of persons

Reduce Human Footprint

• Human population reduction

• More efficient

• Better management of our waste

• Better understanding of ecosystem

• Importance of human-dominated ecosystems and other types

Restoration Aspects

• Hydrologic process: surface water and ground water

• Geological conditions ( rock, soil type, slope, landscape)

• Vegetation: cover materials on land/wetland

• Socio-economic shareholders

• Restoration goals/endpoints

Biological Engineering

• Using vegetation in engineering projects to achieve specific ecological goals

Case study: CA Cities

(Earthquakes)

• San Andreas fault: transform plate boundary between NA and Pacific

• San Francisco + Los Angeles

• Lost of properties and lives due to earthquake

Internal Structure of Earth

• Crust

• Mantle

• Inner core

• Outer core

Physical properties of Earth

• Lithosphere —> Crust/rigid mantle

• Asthenosphere

• Mesosphere

• Liquid outer core

• Inner solid core

Seismology

• Study of earthquakes and seismic waves

Seismic P Wave

• Primary wave

• Push-pull wave

• Travels through solids and liquids

• First arrival/fastest

Seismic S-wave

• Secondary/shear waves

• Slower than P

• Does not go through liquid layers

Asthenosphere

• Low velocity zone, major source of Earth magma

What are the theories of plate tectonics?

• Continental drift

• Seafloor spreading

Evidence of changes on earth

• Mountain belts

• Earthquakes

• Volcanoes

Alfred Wegener

• Pangaea: One super-continent

Seafloor spreading

• Harry Hess

• Seafloor is not a single static piece

• Mid-oceanic ridges/spreading centers where new crust is formed

3 types of plate boundaries

• Divergent: moving apart (O-O)

  • Creates seafloors

  • Mid-oceanic ridges

• Convergent: plates collide (O-C) (O-O) (C-C)

  • O-O : Subduction zone

  • C-C : Shallow earthquakes

  • C - O: Major volcanic mountain belt

• Transform: plates slide past one another (O-O)(C-C)

  • Continous rift offset by transform faults

Wilson Cycle

• Cyclic nature of plate tectonics

Hot Spots

• Form a chain of volcanoes near continents and oceans

Significance of tectonic cycle

• Global zones of resource

• Belts of earthquakes and volcanic activities

• impact landscape + climate

• Foundation for urban development

Convection

• Transfer of hear involving movement of particles

Isostasy

• Principle stating that thicker, more buoyant crust is topographically higher than crust that is thinner and denser

Magnetic reversal

• involves the change of Earth’s magnetic field between normal polarity and reverse polarity

Moho

• Boundary between the crust and mantle

Mid-oceanic ridge

• topographic high commonly found in the central part of oceans characterized by seafloor spreading

Paleomagnetism

• study of magnetism of rocks and the intensity and direction of the magnetic field of Earth in the geological past

Spreading center

• Synonymous with mid-oceanic ridges where new crust is continuously added to the edges of lithospheric plates

Submarine trench

• long and narrow depression on the ocean floor that forms as a result of convergence of two tectonic plates with subduction of one

Triple junction

• three tectonic plates and their boundaries join

Wadati-Benioff zone

• inclined zone of earthquake produced as a tectonic plate is subducted

Case Study: Asbestos

• Group of silicate minerals

• hazardous to human health —> fatal lung diseases

• Fire retardant property for brake lining and insulations

• White asbestos (harmful) blue asbestos (hazardous)

Minerals

• Building blocks of rocks

Mineralogy

• Study of minerals, building blocks of rocks

What must occur for something to be considered a mineral?

• Naturally occurring

• Generally inorganic

• Must be solid

• Orderly crystalline structure

• Well defined chemical composition

What are rocks?

• Any solid mass of minerals/mineral-like matter which occurs naturally

Importance of Rocks and Minerals

• Uses for modern economic development

• Figure out history of Earth

• Manage Earth’s resources

• Important to health and environment

Element

• Substance which cannot be broken down into others by ordinary chemical reactions

Atomic number

• Unique number of protons in an element’s nucleus

Atomic mass number

• Sum of the number of protons and neutrons

Atom,

• smallest unit of a substance that retains properties of that element

  • Protons, Neutrons, Electrons

Molecule

• Smallest unit of a compound that retains properties of that substance

  • Ex: water

Isotopes

• Different number of neutrons and can be stable or unstable

• Stable: retain all protons

• Unstable/radioactive: lose subatomic particles

List the 3 isotopes of carbon

• Carbon 12

• Carbon 13

• Carbon 14

How much of the atoms on the Earth represents the most common elements?

What are the 8 most common elements?

• 97%

• O, Si, Al, Fe, Ca, Na, K , Mg

What group are most minerals?

• Silicates

  • Si and O bonded

What type of arrangement do crystalline structures have?

• 3-D arrangement of atoms