Unit 4: Earth Systems

Unit 4: Earth Systems 1

Introduction

  • Creator: Slides by Jordan Dischinger-Smedes (templates from Slidesgo.com).

  • Purpose: These slides are designed to assist in studying and teaching AP Environmental Science.

  • Resources: Video lectures and daily topic reviews on Instagram available.

  • Support: Donations are welcomed to aid in the creation of these resources.

4.1 Plate Tectonics

Objectives

  • Learning Objective (ERT-4.A): Describe geological changes and events at:

    • Convergent boundaries.

    • Divergent boundaries.

    • Transform plate boundaries.

  • Suggested Skill (2.C): Visual Representations—Explain how environmental concepts visually relate to broader issues.

Essential Knowledge

  • ERT-4.A.1: Convergent boundaries lead to:

    • Mountain formation.

    • Island arcs.

    • Earthquakes.

    • Volcanoes.

  • ERT-4.A.2: Divergent boundaries lead to:

    • Seafloor spreading.

    • Rift valleys.

    • Volcanoes.

    • Earthquakes.

  • ERT-4.A.3: Transform boundaries primarily cause earthquakes.

  • ERT-4.A.4: Maps of global plate boundaries help locate:

    • Volcanoes.

    • Island arcs.

    • Earthquakes.

    • Hot spots.

    • Faults.

  • ERT-4.A.5: An earthquake is triggered when stress overcomes a locked fault, releasing stored energy.

Earth's Structure

  • Core: Dense mass composed of solid nickel and iron, containing radioactive elements that generate significant heat.

  • Mantle: A liquid layer of magma surrounding the core, kept molten by the core's heat.

  • Asthenosphere: A solid yet flexible layer beneath the lithosphere.

  • Lithosphere: A thin, brittle layer of rock made up of tectonic plates.

  • Crust: The outermost layer of the lithosphere, constituting Earth's surface.

Plate Boundaries
Divergent Plate Boundary

  • Plates move apart, driven by rising magma from the mantle.

  • Forms mid-ocean ridges, volcanoes, and rift valleys (on land).

Convergent Plate Boundary

  • Plates move towards each other, causing subduction (one plate going beneath another).

  • Leads to:

    • Mountains (e.g., Himalayas).

    • Island arcs and volcanic activity (e.g., Andes).

    • Earthquakes.

    • Creation of trenches and potential tsunamis.

Transform Fault Plate Boundary

  • Plates slide past each other in opposite directions.

  • Primarily results in earthquakes due to the friction between rough edges of plates.

Convection Cycles (Divergent)

  • Rising magma cools, forcing oceanic plates apart, creating:

    • Mid-ocean ridges.

    • Volcanic activity.

  • As the oceanic plate subducts, it melts back into magma and forces magma up, resulting in:

    • Coastal mountain formations (e.g., Andes).

    • Inland volcanoes.

Convergent Boundary Applications

  • Oceanic-Continental interactions lead to:

    • Volcanic formations and coastal mountains (e.g., Andes).

    • Creation of trenches and tsunamis.

  • Oceanic-Oceanic interactions cause:

    • Formations of mid-ocean volcanoes and island arcs.

    • Offshore trenches.

Transform Fault Boundary Dynamics

  • Plates moving past each other generate faults (cracks in the rock surface).

  • Earthquakes occur when the build-up pressure from stuck edges breaks free, releasing energy that shakes the lithosphere.

Tectonic Map Predictions

  • Ring of Fire: A pattern of volcanoes encircling the Pacific Plate.

  • Transform Faults: Likely locations for earthquakes.

  • Hotspots: Areas with unusually hot magma rising towards the lithosphere, leading to mid-ocean islands (e.g., Iceland, Hawaii).

Practice FRQ 4.1

  • Suggested skill: Visual Representation—Explain the relationship between subduction and volcanic activity.

4.2 Soil Formation & Erosion

Objectives

  • Learning Objective (ERT-4.B): Describe soil characteristics and formation.

  • Suggested Skill (4.B): Identify research methods related to soil studies.

Essential Knowledge

  • ERT-4.B.1: Soils are formed by the weathering, transportation, and deposition of parent material.

  • ERT-4.B.2: Soil is categorized by horizons based on composition and organic material.

  • ERT-4.B.3: Erosion from wind or water can significantly affect soil quality. Protecting soil enhances water quality through effective filtration processes.

What is Soil?

  • Composition: A mix of geologic (rock) and organic materials (living components).

    • Particles: Sand, silt, clay.

    • Humus: The organic component, mainly from decomposed biomass like leaves and animal waste.

    • Nutrients: Essential for plant growth (e.g., ammonium, phosphates).

    • Water and Air: Critical for soil function.

    • Living Organisms: Support nutrient cycling and plant growth.

Soil Formation Processes
Weathering

  • The breakdown of rocks into smaller particles:

    • Physical Weathering: Natural elements (wind, rain, freezing/thawing).

    • Biological Weathering: Tree roots cracking rocks.

    • Chemical Weathering: Effects of acid rain.

Erosion

  • The transport of weathered fragments by wind and rain.

  • Fragments are deposited in new locations, shaping soil boundaries.

Soil Formation Mechanisms

  • From Below: Weathering of parent material contributes to:

    • Sand, silt, clay.

    • Formation of minerals.

  • From Above: Breakdown of organic matter increases humus content, while erosion adds soil particles from various sources.

Factors Affecting Soil Formation

  • Parent Material: Influences soil pH and nutrient content.

  • Topography: Amount of erosion varies with slope—steeper slopes suffer excessive erosion.

  • Climate: Warmer conditions accelerate organic matter breakdown, while precipitation impacts weathering and erosion rates.

  • Organisms: Soil organisms like bacteria and fungi help decompose organic matter, enriching the soil.

Soil Horizons

  • O-Horizon: Organic matter layer; provides nutrients and retains moisture.

  • A-Horizon (Topsoil): Rich in humus and minerals; highest biological activity.

  • B-Horizon (Subsoil): Minerals with minimal organics; some nutrient content.

  • C-Horizon: Least weathered soil closest to parent material, also known as bedrock.

Soil Degradation

  • Loss of Soil Capability: Inability to support plant growth.

    • Loss of Topsoil: Caused by tilling and vegetation loss leading to erosion.

    • Compaction: Results from machinery and livestock reducing moisture retention, fostering erosion.

    • Nutrient Depletion: Repetitive crop growth depletes essential nutrients over time.

Practice FRQ 4.2

  • Design an investigation to measure climate effects on soil formation, identifying independent/dependent variables.

4.3 Soil Composition & Properties

Objectives

  • Learning Objective (ERT-4.C): Analyze similarities/differences among soil types.

  • Suggested Skill (4.C): Describe research methods related to soil studies.

Essential Knowledge

  • ERT-4.C.1: Water holding capacity varies among soil types and affects productivity.

  • ERT-4.C.2: Soil horizon composition impacts its porosity, permeability, and fertility.

  • ERT-4.C.3: A variety of methods exist to test soil properties for informed agricultural decisions.

  • ERT-4.C.4: The soil texture triangle helps identify and compare soil types based on sand, silt, and clay percentages.

Soil Particle Size, Texture, and Porosity

  • Soil comprises three categories based on size:

    • Largest: Sand

    • Medium: Silt

    • Smallest: Clay

  • Soil Texture: The percentage of each particle type must equal 100% (e.g., 40% sand, 40% silt, 20% clay).

  • Porosity: Influenced by particle size—sand has larger pores, ensuring better air and water infiltration, while clay has tighter pores, restricting flow.

Soil Texture Chart

  • Soil texture is assessed through the percentages of sand, silt, and clay.

  • Example: Loam = 40% sand, 40% silt, 20% clay.

  • Utilization of the Soil Texture Chart involves determining percentages starting with sand and correlating with clay completion.

  • Example Problem: Identify relative ratios from given vectors or charts.

Porosity, Permeability, and Water Holding Capacity

  • Porosity: Amount of pore space indicates drainage efficiency—higher sand content leads to higher porosity.

  • Permeability: Indicates how easily water drains through soil, directly linked to porosity.

  • Water Holding Capacity: Denotes soil's ability to retain water—more porous equates to lower holding capacity, affecting agricultural viability.

Soil Fertility Factors

  • Essential Nutrients: Include nitrogen (N), phosphorus (P), potassium (K), magnesium (Mg), calcium (Ca), and sodium (Na).

  • Factors Increasing Fertility:

    • Presence of organic matter and humus facilitates nutrient availability.

    • Decomposers promote nutrient recycling.

  • Factors Decreasing Fertility:

    • Acidic environments leach beneficial nutrients.

    • Erosion and excessive farming practices deplete nutrient quality.

Characteristics and Tests of Soil Quality

  • Tests and Indicators:

    • Texture: Settling in water identifies component percentages.

    • Permeability: Through timing water drainage gives insights into soil effectiveness.

    • pH: Measuring acidity/alkalinity determines nutrient availability.

    • Color: Darker hues often correlate with richer organic content.

    • Nutrient Level: Specific measures for key nutrients affecting plant growth.

Practice FRQ 4.3

  • Identify a soil test and articulate how the results could guide farming decisions.

4.4 Atmosphere

Objectives

  • Learning Objective (ERT-4.D): Describe Earth's atmospheric structure and composition.

  • Suggested Skill: Visual representation explanations.

Essential Knowledge

  • ERT-4.D.1: Major gases in the atmosphere exist in specific relative abundances.

  • ERT-4.D.2: Atmospheric layers are categorized by temperature, including:

    • Troposphere

    • Stratosphere

    • Mesosphere

    • Thermosphere

    • Exosphere

Gases of Earth’s Atmosphere

  • Nitrogen: 78% (inert, needs fixation by plants).

  • Oxygen: 21% (needed for respiration).

  • Argon: 0.93% (noble gas).

  • Carbon Dioxide: 0.04% (acts as a greenhouse gas).

  • Water Vapor: Varies between 0-4%.

Characteristics of Layers

  • Exosphere: Outermost layer merging with space.

  • Thermosphere: Highest temperatures absorb harmful radiation; responsible for auroras.

  • Mesosphere: Middle layer possessing the coldest temperatures.

  • Stratosphere: Contains ozone (O3) layer absorbing UV radiation.

  • Troposphere: Weather occurs here with the densest gas composition.

Temperature Gradient in Layers

  • Atmospheric temperature changes based on distance from Earth:

    • Thermosphere: Temperature rises significantly.

    • Mesosphere: Temperature decreases with altitude.

    • Stratosphere: Temperature rises with altitude from UV radiation.

    • Troposphere: Temperature decreases with altitude.

Practice FRQ 4.4

  • Identify a layer demonstrating inverse temperature-altitude relationships and explain.

4.5 Global Wind Patterns

Objectives

  • Understanding atmospheric circulation includes:

    1. Energy from sunlight.

    2. Density properties of air.

    3. Earth's rotation (Coriolis Effect).

Air Properties

  • Warm Air: Rises and holds more moisture compared to cold air.

  • Cool Air: Sinks, unable to sustain moisture (leading to condensation and rainfall).

  • Pressure Patterns: Low pressure at the equator due to rising air; high pressure at 30 degrees due to descending air.

Coriolis Effect

  • Describes the deflection of traveling air due to Earth’s rotation.

  • Influences wind patterns between various latitudes:

    • 0 to 30°: air moves East to West.

    • 30 to 60°: air travels West to East.

Global Wind Patterns Summary

  1. Air moves from high-pressure areas (30°) towards low-pressure regions (0° and 60°).

  2. Results in:

    • Easterly trade winds between 0° - 30° driving ocean currents.

    • Westerlies between 30° - 60° driving prevailing weather patterns.

Practice FRQ 4.5

  • Discuss how the sun drives air circulation patterns illustrated in a model.

4.6 Watersheds

Objective

  • Learning Objective (ERT-4.F): Discuss watershed characteristics.

Essential Knowledge

  • ERT-4.F.1: Watersheds include area, length, slope, soil types, vegetation, and divides.

Definition and Elements of a Watershed

  • Watershed: Area draining into a body of water (river, lake, etc.).

  • Vegetation Role: Increases infiltration and groundwater recharge.

  • Soil Permeability: Affects runoff vs. infiltration rates.

Impact of Human Activities

  • Actions such as agriculture, urbanization, and deforestation degrade water quality.

  • Impact leads to processes such as poor water filtration, increased erosion, and habitat loss.

Chesapeake Bay Watershed Case Study

  • Characteristics: Mix of freshwater and saltwater, nutrient-rich estuaries.

  • Ecosystem Services: Tourism, water filtration, habitats for biodiversity, storm protection.

Nutrient Pollution and Eutrophication

  • Algae blooms triggered by excess nitrogen and phosphorous lead to hypoxic dead zones.

  • Major pollution sources include:

    1. Sewage discharge.

    2. Agriculture runoff.

    3. Industrial waste.

Effects of Deforestation

  • Leads to increased soil erosion, reduced organic matter, and sediment influx into waters.

  • Impacts water and temperature, contributing to ecosystem degradation.

Solutions to Reduce Watershed Pollution

  • Implementing Riparian Buffers to enhance nutrient removal.

  • Animal Manure Management and use of cover crops to prevent nutrient runoff.

  • Septic System Upgrades for better nutrient absorption and groundwater protection.

Practice FRQ 4.6

  • Explain how deforestation impacts water quality in watersheds.

4.7 Solar Radiation & Earth’s Seasons

Objectives

  • Learning Objective (ENG-2.A): Explain solar influence on Earth's surface.

Essential Knowledge

  • Insolation: Solar radiation reaching an area measured in watts/m².

  • Seasonal Variation: Influenced by Earth's tilt, which determines solar radiation intensity and daylight hours.

Solar Intensity & Latitude

  • Higher solar intensity at the equator than at higher latitudes due to angle and atmospheric thickness effects.

Solar Intensity & Season

  • Tilt of Earth’s Axis: Alters angle and duration of sunlight received during seasons, influencing seasonal climatic variations.

Albedo and Temperature Effects

  • Albedo: Measure of reflectivity of surfaces influences heating of the Earth. Lower albedo= higher heat absorption.

  • Urban Heat Islands: Areas in cities experience higher temperatures than surrounding rural regions due to materials with low albedo.

Practice FRQ 4.7

  • Identify a season depicted in a diagram and discuss how Earth’s axial tilt influences seasonal change.

4.8 Earth's Geography & Climate

Objectives

  • Learning Objective (ENG-2.B): Describe geography's impact on weather/climate.

Essential Knowledge

  • Weather and climate vary based on geographical and geological factors, such as mountains and ocean temperatures.

Climate Determinants

  • Geography: Influences climate via insolation and atmospheric interactions:

    • Mountains: Disrupt wind patterns and determine rain shadow effects.

    • Oceans: Moderate local temperatures and increase air humidity, affecting precipitation.

Rain Shadow Effect

  • Landscapes adjacent to mountains receive different moisture levels due to elevation impacting rain distribution.

Global Wind Patterns & and Their Relation to Climate

  • Wind patterns determined by Earth's rotation and convection affect climate manifests globally.

Practice FRQ 4.8

  • Analyze precipitation patterns for specified regions.

4.9 El Nino & La Nina

Objectives

  • Learning Objective (ENG-2.C): Explain environmental changes from El Niño or La Niña.

Essential Knowledge

  • El Niño and La Niña represent oscillations affecting weather patterns due to shifting ocean temperatures in the Pacific Ocean.

Ocean Currents and Climate

  • Global Gyres: Circular ocean current patterns created by global wind affecting temperature and nutrients distribution.

  • Upwelling Zones: Areas significant for fisheries production through nutrient replenishment.

El Niño-Southern Oscillation (ENSO)

  • ENSO is characterized by alternating conditions between El Niño (warmer) and La Niña (cooler) across the Pacific, impacting global meteorological outcomes.

Effects of El Niño and La Niña

  • El Niño: Warmer-western shifts cause drought in Australia while increasing rainfall in Americas.

  • La Niña: Strengthens upwelling, increasing fish stocks off South America yet causing dry spells in some regions.

Practice FRQ 4.9

  • Discuss two environmental issues arising from El Niño events.