Earth’s Subsystems & Institutional Context – Comprehensive Notes

Philosophy & Institutional Context

• University of Perpetual Help System DALTA (UPHSD)

  • Invokes Divine guidance for national development via quality education.

  • Embodies the value of “Helpers of God.”

  • Core maxim: “Character Building is Nation Building.”

• Vision

  • Aspires to be a leading university in the Philippines.

  • Serves as catalyst for human development, nurturing Christian (Catholic) values.

  • Envisions Filipinos living in peace, abundance, and global competitiveness in science, arts, humanities, sports, and business.

• Mission

  • Develops well-rounded, Christ-centered, service-oriented, research-driven Filipinos.

  • Produces graduates committed to high quality of life, health care, education, and social responsibility.

Opening & Closing Prayers

• Begin and end sessions with standard Catholic prayers invoking:

  • Guidance of the Holy Spirit for wisdom and knowledge.

  • Gratitude for learning, application of lessons in daily life.

  • Intercession of “Our Mother of Perpetual Help.”

• Reinforces spiritual atmosphere before/after academic discourse.

Class Flow (Work Plan)

• Opening prayer → Recitation of PVM (Philosophy, Vision, Mission) → Attendance check → Skill-building activity → Motivation → Discussion → Activity Time → Closing prayer.

Skill-Building Activity: Unscramble

• EPOGERSHE → Geosphere

• IBOSEHPRE → Biosphere

• EOPERSDHRHY → Hydrosphere

• AMOHEREPS → Atmosphere

Motivation: Terrarium Analogy

• Guide Questions

  • Components: soil, plants, water, air, container (glass/plastic), possible decomposers (microbes).

  • Functions

  • Soil = nutrient & physical support (geosphere proxy).

  • Water = hydration & solvent for biochemical reactions (hydrosphere).

  • Air trapped in container = gas exchange, O$2$/CO$2$ balance (atmosphere).

  • Plants/organisms = photosynthesis, respiration, nutrient cycling (biosphere).

  • Comparison to Earth system

  • Terrarium = miniature closed-system model; demonstrates interdependence and cycling of matter/energy among Earth’s subsystems.

Learning Objectives

• Define Earth’s four subsystems.

• Explain that Earth consists of subsystems across whose boundaries matter & energy flow.

• Appreciate the importance of each subsystem for sustaining life & planetary stability.

Key Concepts: Earth’s Subsystems (Overview)

• Earth = rocky, terrestrial planet with active surface (mountains, valleys, plains).

• “System” = set of interacting components.

• Scientists treat Earth as an integrated system of four major subsystems:

  1. Geosphere

  2. Hydrosphere

  3. Atmosphere

  4. Biosphere

Geosphere

• Definition: Entire solid Earth from inner core to crust.

• Structural Layers (inside → out):

  • Inner Core (solid Fe, Ni); radius $1220\,\text{km}$.

  • Outer Core (liquid Fe, Ni); thickness $2260\,\text{km}$; source of magnetic field.

  • Mantle (upper, transition zone, lower/mesosphere; largely silicate rocks; includes semi-plastic asthenosphere).

  • Crust (oceanic $\approx5−10\,\text{km}$; continental $\approx30−50\,\text{km}$).

• Additional terms: Gutenberg & Lehmann discontinuities = seismic boundaries between core–mantle & inner–outer core.

• Components: rocks, minerals, non-living soil portion, fossils.

• Importance

  • Provides essential nutrients for life.

  • Volcanic degassing supplies atmospheric gases.

  • Plate tectonics create geographic barriers → drives evolution.

Hydrosphere

• Definition: All water (solid, liquid, vapor) on/in/above Earth.

• Global distribution

  • Water covers $\approx71\%$ of Earth’s surface.

  • Saline water: $97\%$ (oceans).

  • Freshwater: $3\%$ → $69\%$ frozen (ice/glaciers), $30\%$ groundwater, $1\%$ surface water.

• Cryosphere (ice realm) usually treated as hydrosphere subset.

• Forms: oceans, seas, rivers, lakes, glaciers, groundwater, atmospheric vapor/clouds.

Atmosphere

• Definition: Gaseous envelope around Earth.

• Composition

  • $\text{N}_2$ $=78\%$

  • $\text{O}_2$ $=21\%$

  • Other gases (Ar, CO$_2$, Ne, etc.) $=0.04\%$

• Layering (bottom → top)

  1. Troposphere (0–12/18 km): weather, >80\% atmospheric mass, most H$_2$O vapor.

  2. Stratosphere (11–50 km): Ozone layer → temp increases with altitude.

  3. Mesosphere (50–80 km): burns meteoroids; temp decreases upward.

  4. Thermosphere (80–800 km): auroras, ISS orbit, high temp but low density.

  5. Exosphere (>800 km → space): extremely thin, collision-less.

• Functions

  • Supplies gases for life (CO$2$ for photosynthesis, O$2$ for respiration).

  • Transfers heat (controls climate, weather).

  • Ozone absorbs harmful UV radiation.

  • Moderate day–night temperature extremes.

Biosphere

• Definition: Global sum of all ecosystems; region where life exists (ground, water, air).

• Interacts with geosphere, hydrosphere, atmosphere simultaneously.

• Distinction

  • Ecosystem = localized community + environment.

  • Biosphere = planetary-scale aggregation of ecosystems.

Interactions & Flow of Matter/Energy

• Subsystems linked via biogeochemical cycles.

• General principles

  • Matter & energy cross subsystem boundaries.

  • Example events

  • Volcanic eruptions (geosphere ↔ atmosphere/hydrosphere/biosphere).

  • Water cycle (hydrosphere ↔ all).

• Atmosphere safeguards life: UV shielding, heat retention.

• Biosphere energy source: ultimately the Sun.

  • Energy enters via photosynthesis → moves through trophic levels → exits as heat.

  • Represented by food chains & food webs.

Key Cycles

• Water (Hydrologic) Cycle

  1. Evaporation

  2. Condensation

  3. Precipitation

  4. Infiltration

  5. Collection/Run-off

  6. Repeat

• Carbon Cycle

  1. Photosynthesis (CO$_2$ → organic C)

  2. Cellular respiration (organic C → CO$_2$)

  • Also involves decomposition, fossilization, combustion, ocean uptake.

• Energy Cycle in Ecosystem

  1. Input: Solar radiation.

  2. Capture: $\text{6 CO}<em>2 + 6 \text{H}</em>2\text{O} \xrightarrow{\text{light}} \text{C}<em>6\text{H}</em>{12}\text{O}<em>6 + 6 \text{O}</em>2$ (photosynthesis).

  3. Transfer: Producers → consumers → decomposers.

  4. Loss: Heat at each trophic step (Second Law of Thermodynamics).

  5. Recycle: Nutrients returned by decomposers to geosphere/hydrosphere.

Integrative Questions / Activities

• Describe a natural disaster (earthquake, typhoon, drought) and trace its impacts across all subsystems; predict long-term effects (e.g., soil erosion, habitat loss, climate feedbacks).

• Analyze solar energy’s influence on climate and subsystem interactions.

• Activity 1.4: Acrostic “EARTH.”

  • Example: “E = Exosphere.” Students fill A, R, T, H with learned terms.

Practical & Ethical Implications

• Understanding subsystem linkages aids disaster preparedness & sustainable resource management.

• Human actions altering one subsystem (e.g., CO$_2$ emissions) propagate through others (climate change, ocean acidification, biodiversity loss).

• Stewardship perspective rooted in institutional philosophy: care for creation reflects moral responsibility.

Inspirational Quote

• Radhanath Swami: “Mother Nature is always speaking… understood within the peaceful mind of the sincere observer.”

  • Encourages attentive, respectful study of Earth’s systems.

Key Numerical/Statistical References (LaTeX)

• Surface water coverage: $71\%$ of Earth.

• Oceanic (salt) water: $97\%$, freshwater $3\%$ → $69\%$ frozen, $30\%$ groundwater, $1\%$ surface.

• Atmospheric composition: $\text{N}<em>2 = 78\%$, $\text{O}</em>2 = 21\%$, other $= 0.04\%$.

• Inner core radius $\approx1220\,\text{km}$; total Earth radius $\approx6371\,\text{km}$.

Suggested Study Tips

• Create diagrams of subsystem interactions.

• Memorize layer orders (atmosphere & geosphere) using mnemonics.

• Practice tracing matter/energy for specific scenarios (e.g., water droplet or carbon atom journey).

• Relate cycles to daily experiences (weather, food consumption, fuel use).