Earth Systems and Resources — Comprehensive Study Notes

Ecological Worldviews

  • Anthropocentric
    • human centered
    • “Anthro” refers to humans
    • Focus is on human needs over all others
  • Biocentric
    • balance between living things
    • Focus on human needs and ecological needs
  • Ecocentric
    • Environment centered
    • Focus is on preserving environment over everything else

Plate Tectonics

  • Continental Drift and Pangaea
    • Continental Drift: theory that the continents on Earth have moved and continue to move relative to each other over geological time
  • Earth’s Layers (major structural terms)
    • Core (inner and outer)
    • Mantle (magma)
    • Asthenosphere
    • Lithosphere
    • Crust
    • Notes from the diagram:
    • Crust = outermost solid shell
    • Mantle = below crust; partially molten zones
    • Lithosphere = crust + rigid upper mantle
    • Asthenosphere = partially molten, allows plate movement
    • Inner core = solid; outer core = liquid
  • Plate Tectonics: movement of lithospheric plates over the asthenosphere
    • Plate Boundary definitions: where two plates meet
    • Divergent boundaries: plates move apart
    • Convergent boundaries: plates move toward each other
    • Subduction: one plate sinks beneath another at a convergent boundary
    • Transform boundaries: plates slide past one another horizontally
  • Continental Drift and Pangaea implications
    • Explains similarity of coastlines, fossil distributions, and tectonic features across continents

Plates and Plate Boundaries

  • Plate Boundary types and associated features
    • Divergent boundaries
    • Oceanic spreading centers; new ocean crust formed
    • Mid-ocean ridges
    • Convergent boundaries
    • Oceanic-Continental: subduction of oceanic plate beneath continental plate; trench formation; volcanic arcs (e.g., Andes)
    • Oceanic-Oceanic: subduction resulting in volcanic island arcs; trenches
    • Continental-Continental: crust thickens, mountain building; no subduction to great depths, large mountain belts (e.g., Himalayas)
    • Transform boundaries
    • Plates grind past each other; faults (e.g., San Andreas Fault)
  • Subduction, trenches, and volcanic arcs
    • Subduction zones form trenches and volcanic arcs where subducting slab melts and forms magma
    • Mid-ocean ridges and spreading centers are sites of new crust formation
  • Key boundary features and terms
    • Oceanic crust vs. Continental crust
    • Lithosphere vs. Asthenosphere
    • Magma generation at subduction zones and at divergent boundaries
    • Islands arcs, volcanic arcs, trenches
    • Hot spots (e.g., Hawaii) as another source of volcanism independent of plate boundaries
  • Regional plate configurations (examples from the figure set)
    • Juan de Fuca Plate; Cocos Plate; Nazca Plate; Pacific Plate; North American Plate; Eurasian Plate; African Plate; Indian-Australian Plate; Caribbean Plate; South American Plate; Antarctic Plate
    • Major currents in plate tectonics mapping include East Pacific Rise, Mid-Atlantic Ridge, and others
  • San Andreas Fault as a classic transform boundary example
  • Plate tectonics in changing coastlines and mountain building

Environmental Consequences of Plate Tectonics

  • Shifting plates can drive major environmental and ecological changes
    • Climate changes related to continental drift, volcanic activity, and reef/mangrove disruption
    • Seismic events: earthquakes
    • Volcanic activity: eruptions and lava flows
    • Tsunamis: triggered by submarine earthquakes, volcanic eruptions, or landslides

Volcanoes

  • Volcanic origin and processes
    • Result from subduction of tectonic plates
    • Descending plate sinks into high temperatures/pressures; water and gases are released from rocks
    • Water lowers the melting point of overlying rock, forming magma that can ascend to the surface
  • Examples and regional activity
    • Includes famous volcanoes and volcanic arcs along convergent boundaries (e.g., Pacific Ring of Fire)

Earthquakes

  • Causes and mechanics
    • Caused by the release of accumulated energy as rocks in the lithosphere suddenly shift or break along faults
    • Energy is released as seismic waves
  • Seismic wave propagation and measurement
    • Waves move upward and outward from the earthquake focus
    • Magnitude measures ground motion, indicated by wave amplitude

Tsunami

  • Definition and mechanism
    • Giant undersea wave caused by an earthquake, volcanic eruption, or landslide
    • Wave speed in deep water exceeds 550 mph550\ \text{mph} (approx.)
    • Wave height can be small in deep water (about 1 m) but can rise dramatically near shore (e.g., up to 30.5 m30.5\ \text{m})
  • Notable example
    • Magnitude Mw=9.3M_w = 9.3 earthquake in the Indian Ocean in 2004 triggered a devastating tsunami

Environmental Impact of Tsunami

  • Coastal environmental damage
    • Severe damage to coastal wetlands, biodiversity, coral reefs, and mangrove forests
    • Flooding can spread industrial chemicals, solids, and liquids

Human Contribution and Impact of Tsunami

  • Anthropogenic effects magnifying tsunami damage
    • Destruction of coral reefs and mangroves reduces natural buffering against storms
    • Increased incidence of disease and water contamination
    • Psychological impacts on affected populations

Environmental Consequences of Plate Tectonics – Discussion Prompts

  • What would be some environmental or ecological consequences of volcanoes, earthquakes, or tsunamis?
  • Could volcanic activity ever confer benefits (e.g., soil fertility, mineral deposits, new land formation)?
  • What are some economic consequences of plate tectonic processes?
  • What are the benefits of increased technology to measure tectonic activity?

Altered Coastlines

  • Visual before/after examples show coastline changes due to tectonic and volcanic processes

Soil Formation and Erosion (4.2)

  • Soil Formation (Pedogenesis) and Erosion
    • Erosion by wind or water
    • Deposition of particles
    • Interaction with living organisms
    • Soil formation factors: time, climate, organisms, topography, parent material
  • Why soil is important
    • Medium for plant growth
    • Filters water
    • Helps reduce pollution by carbon cycling and nutrient cycling
    • Habitat for organisms
    • Interesting facts: earthworms can move up to ~100 tons100\text{ tons} of soil per year; a spoonful of soil contains more microorganisms than people on Earth
  • What makes quality soil?
    • Organic content, appropriate moisture, living organisms in topsoil, physical structure
  • Soil Composition (typical soil)
    • Mineral particles: 45%45\% (weathered rock)
    • Organic material: 5%5\% (litter, dung, decomposed matter)
    • Water: 25%25\%
    • Air: 25%25\%
  • Soil Formation processes
    • Two directions: breakdown of rocks via weathering and decomposition of organic matter
  • Soil Particles – Texture
    • Particles: gravel, sand, silt, clay
    • Texture determined by size proportions; a soil triangle is a tool for classifying soil texture from sand/silt/clay percentages
    • Typical naming from texture triangle examples: loam, clay loam, sandy loam, etc.
  • Soil Properties – Texture-driven effects
    • Coarse-textured soils (sandy) have excellent drainage
    • Fine-textured soils (high in clay) have poor drainage, low soil oxygen, and high nutrient holding capacity due to negative surface charge on clay minerals
  • Physical Structure – Texture and soil naming
    • Soil triangle usage to determine soil name from sand, silt, and clay percentages
  • Soil Properties – Chemical
    • Soil acidity (pH) measured on the pH scale
    • Most soils range from pH≈4−8pH\approx 4-8; optimum nutrient availability generally around pH≈6−7pH\approx 6-7
    • Negative charge on clay minerals attracts positively charged nutrients (e.g., K+,Ca2+,NH4+K^{+}, Ca^{2+}, NH_{4}^{+})
  • Leaching in Soil
    • Loss of water-soluble nutrients due to rain/irrigation
    • Acid rain can leach heavy metals (e.g., lead, aluminum, cadmium) into soil
  • Soil Organisms
    • Millions of microorganisms in 1 teaspoon of fertile soil
    • Ecosystem services: decomposition, nutrient cycling, breaking down toxins, cleansing water, soil aeration
  • The Soil Profile – Horizons (cross-sectional view)
    • O Horizon: surface layer of organic residues (leaf litter)
    • A Horizon: topsoil; high humus content; abundant organisms
    • B Horizon: subsoil; less humus; more inorganic; plant roots can penetrate
    • C Horizon: parent material; weathered rock; contains larger rock fragments
    • (Note: E Horizon is commonly described as a zone of leaching in standard soil profiles, but the provided material lists O, A, B, C and mentions a de-emphasized E horizon in some figures.)

Soil Erosion

  • The wearing away or removal of soil (especially topsoil) from land
  • Causes
    • Wind and water erosion
    • Poor agricultural practices, removal of plant cover, unsound forestry practices

Earth’s Atmosphere (4.4)

  • Atmosphere composition
    • Approximately 21% O<em>221\%\,O<em>2 and 78% N</em>278\%\,N</em>2; ~1%1\% other gases (argon, CO2, neon, helium, etc.)
    • Density decreases with altitude
    • Shields Earth from high-energy radiation
  • Atmospheric Layers (from surface upward)
    • Troposphere: 0−16 km0-16\,\text{km}; weather occurs here; temperature generally decreases with altitude
    • Stratosphere: 16−50 km16-50\,\text{km}; temperature increases with altitude; ozone layer absorbs UV
    • Mesosphere: 55−80 km55-80\,\text{km}; temperature decreases with altitude
    • Thermosphere: 80−500 km80-500\,\text{km}; very hot due to absorption of X-rays and shortwave UV; source of aurora borealis
    • Exosphere: >500\,\text{km}; outermost layer; atmosphere gradually thins into space
  • Temperature profiles (summary visuals)
    • Temperature gradients across layers; tropopause, stratopause, mesopause markers

Global Wind Patterns and Air Circulation (4.5)

  • Four key properties driving air circulation
    • Density: warm air is less dense than cool air
    • Water vapor capacity: air’s capacity to hold water vapor
    • Adiabatic heating/cooling
    • Latent heat release
  • Convection currents (definition)
    • Transfer of energy by convection in the atmosphere; rises when heated, falls when cooled
  • Hadley, Ferrell, and Polar cells
    • Hadley cells: near the equator; rising warm air and north-south circulation to ~30° latitude; ITCZ (intertropical convergence zone)
    • Ferrell cells: between ~30° and ~60° latitude; subtler circulation
    • Polar cells: ~60° to 90° latitude; cooler, denser air sinks at high latitudes
  • Global wind belts and associated features
    • Equatorial low (Doldrums)
    • Trade winds (northeast in NH and southeast in SH)
    • Subtropical highs
    • Westerlies
    • Polar easterlies
    • 30°N/S narrow belt of warm, moist air rising and rainfall near equator; 30°N/S subtropical high pressure zones with dry conditions
    • Horse latitudes near 30° lat where air subsides
  • Ocean currents and Coriolis influence on winds
    • Gyres: large circular ocean current systems driven by wind patterns and the Coriolis effect
    • Major currents include Gulf Stream/North Atlantic Drift, California Current, North Pacific Drift, Humboldt Current, Canary Current, Benguela Current, Kuroshio, Oyashio, etc.
  • Coriolis Effect (deflection due to Earth’s rotation)
    • Northern Hemisphere: deflection to the right of motion
    • Southern Hemisphere: deflection to the left
    • Demonstrated via rocket illustrations and general wind/air circulation patterns
  • Hurricanes and Coriolis
    • Formation requires Coriolis effect to impart rotation around a low-pressure center
    • Spin orientation differs hemispherically (NH clockwise or counterclockwise as appropriate; NH hurricanes rotate counterclockwise; SH storms rotate clockwise)
  • Winds and surface features near the equator/latitudes
    • Trade winds vs. westerlies; subpolar lows and subtropical highs
    • Upwelling zones and major currents influenced by wind patterns and the Coriolis effect

Solar Radiation, Seasons, and Climate (4.7)

  • Solar radiation and uneven heating of Earth
    • Tilt of the Earth: ≈23.5∘\approx 23.5^{\circ}
    • Surface area differences: equator vs. poles; more energy per unit area at the equator
    • Shape of Earth affects how sunlight is distributed
  • Temperature changes with latitude
    • High latitudes receive less insolation and are cooler; equator receives more insolation and is warmer with higher precipitation due to warm air rising
    • Energy must pass through more atmosphere at high latitudes, reducing energy reaching the surface
  • Temperature changes with altitude
    • Altitudinal temperature gradients create distinct biomes (e.g., alpine zones, montane forests)
  • Albedo Effect
    • Reflectivity of surfaces; higher albedo surfaces reflect more solar radiation, affecting local and global temperatures
  • Feedback Loops in climate
    • Positive Feedback Loop: amplifies changes, moving away from equilibrium
    • Negative Feedback Loop: dampens changes, helping restore equilibrium
  • Seasons
    • Determined by axial tilt and orbit; in the NH, tilt toward the Sun for roughly half the year; spring equinox ~March 21; fall equinox ~Sept 22; warm season in NH corresponds to days with greater insolation
  • The Greenhouse Effect (overview)
    • Sunlight penetrates the atmosphere; Earth’s surface heats up and emits infrared radiation
    • Greenhouse gases absorb infrared radiation and re-emit heat, warming the lower atmosphere
    • Increased concentrations of greenhouse gases intensify this effect

Weather vs Climate (77)

  • Weather
    • Conditions of the atmosphere over a short period of time
  • Climate
    • What the atmosphere is like over long periods and spaces; patterns over decades
    • Climate normals: typically 30-year averages used for comparisons
  • Relationship
    • Weather is the short-term state of the atmosphere; climate is the long-term statistical average of weather

Climate Patterns and Microclimates

  • Climate patterns influenced by latitude and altitude
    • Near-equatorial regions: warm, high precipitation due to intense insolation and rising air
    • Mid-latitudes: variable with westerlies and storm tracks
    • High latitudes: cooler with lower precipitation in some regions, but can have heavy snow depending on moisture sources
  • Microclimates and Rain Shadow Effect (4.2)
    • Rain shadow: mountains create a wet windward side and a dry leeward side
    • Process: moisture-laden air rises on windward side, cools, condenses, and releases rainfall; dry air descends on leeward side, creating arid conditions

Weather and Climate-Related Phenomena

  • Hurricanes (tropical cyclones)

    • Require warm surface water, low pressure, Coriolis effect, organization around a low-pressure center
    • More intense with greater ocean heat; KatrinA is a case study example

  • Tornadoes

    • Form from severe convective storms with strong vertical wind shear and atmospheric instability
    • Characterized by a debris cloud and a visible funnel

  • ENSO: El Niño and La Niña (4.9, 4.10–4.12 sections)

    • ENSO: periodic large-scale warming (El Niño) and cooling (La Niña) of surface waters in the tropical eastern Pacific
    • El Niño effects: suppression of upwelling off the coast of South America, leading to reduced marine productivity, droughts in some regions, and wet conditions in others
    • La Niña effects: enhanced upwelling and cooler sea surface temperatures in the equatorial Pacific; increased wind and monsoon variations; differing regional rainfall and cyclone activity compared to El Niño
    • Short-term climate changes: El Niño and La Niña alter global weather patterns across multiple regions (Atlantic, Pacific, Indian Oceans)
    • Upwelling in normal conditions vs. El Niño conditions: normal upwelling nutritious water in Humboldt Current; El Niño reduces upwelling

Ocean Circulation and Global Climate (Thermohaline Circulation)

  • Ocean circulation patterns and gyres
    • Driven by prevailing winds and unequal heating; generate surface currents and gyres
    • Major gyres: North Pacific Gyre, South Pacific Gyre, North Atlantic Gyre, South Atlantic Gyre, Indian Ocean Gyre
    • The Gulf Stream and the North Atlantic Drift transport heat from the tropics toward higher latitudes
    • Kuroshio, Oyashio, Humboldt, Benguela, Canary, California, Brazil, Agulhas, East Australian currents are all part of global current systems
  • Thermohaline Circulation (the Ocean Conveyor Belt)
    • Global pattern of deep-water formation and surface flow
    • Driven by density differences created by temperature (thermo) and salinity (haline)
    • Cold, salty water sinks in high-latitude regions and warm water rises near the equator, enabling large-scale global mixing of heat and nutrients
    • Important for distributing heat and nutrients and influencing climate patterns
  • Upwelling and vertical mixing
    • Upwelling brings nutrient-rich deep water to the surface and supports productive fisheries (e.g., along the western coasts of continents)
    • Vertical mixing of warm surface water with cooler deeper water alters temperature and nutrient profiles

Global Climate Impacts and Observations

  • Global effects of ENSO events (El Niño and La Niña)
    • El Niño tends to bring cooler/wetter conditions to some regions and drought to others; global weather disruptions include heavy rainfall in some areas and droughts in others
    • La Niña tends to bring opposite patterns: enhanced upwelling, more rainfall in some regions, droughts in others, and generally different cyclone activity patterns
  • 30-year climate normals and regional variability
    • Geography, ocean currents, mountains, and land-sea contrasts influence local climates and microclimates

Additional Reference Points and Terms

  • Boundaries and features recap
    • Divergent boundaries: new crust formation; mid-ocean ridges; ocean spreading centers
    • Convergent boundaries: subduction zones; trenches; volcanic arcs; mountain building
    • Transform boundaries: lateral plate movement; fault lines (San Andreas)
  • Notable geographic features
    • Ring of Fire: high volcanic and seismic activity around the Pacific Plate boundary
    • Oceanic trenches, island arcs, mountain belts, mid-ocean ridges, and hot spots
  • Key processes and their connections to Earth systems
    • Plate tectonics influence climate through volcanic emissions, atmospheric composition changes, and long-term changes in sea level and ocean circulation
    • Soil formation and erosion influence land productivity, nutrient cycles, and ecosystem health
    • Atmosphere and oceans interact to regulate climate through heat transport, wind patterns, and circulation systems

Labs/Activities Mentioned

  • Oreo Plate Tectonics
  • Physical and Chemical Characteristics of Soil Lab
  • Ocean Circulation Lab
  • (Other activities listed as part of the unit)