AICE Marine Science Exam Notes

  • Exam Preparation Tips

    • Review all 5 AICE objectives, practical skills, scientific method, and corrected AICE exams.
    • Check the back of the test as soon as it’s received.
    • Use X's on graphs, label each axis with units, and maintain consistent increments.
    • Generally, X data is presented first, followed by Y data for graphing.
    • Rulers are recommended for drawing graphs.

  • Mathematical Skills

    • For "describe" command word: reference graphs/charts/tables with numerical manipulation (e.g., averages, ranges).
    • Show all mathematical work and use appropriate units for rates (e.g., average growth per year, meters/second).
    • Be familiar with calculating averages and percent changes.

  • Graphical Representation

    • Understand how to draw pyramids of energy, biomass, and numbers (should resemble a tiered cake).
    • Use sharp pencils for accurate graphing.

  • Scientific Method

    • Experimental design occurs in a lab setting, typically using tanks of seawater.
    • Keep two variables constant and data should be quantitative with only one variable changed.
    • Ideally, collect at least ten samples, and repeat the experiment to average data.
    • A hypothesis can only be supported or refuted, never proven; consistent support can lead to a theory.
    • Example theories: 3D Theory of Atoll formation, Theory of Plate Tectonics.

  • Handling Variables in Experiments

    • Human error and uncertainty should be noted; increasing sample size and repetition improves reliability.
    • Take care with lab safety, using goggles and gloves, especially when handling living organisms.

  • Objective 1: Kinetic Particle Theory

    • Understand water states: solid, liquid, gas.
    • Atom structure: nucleus (protons & neutrons) with electrons in shells.
    • Sea water consists of various elements and compounds.
    • Bonding Types:
    • Covalent (sharing electrons): e.g., H₂O, CO₂
    • Ionic (transfer of electrons): e.g., NaCl, CaCO₃
    • Common salts in seawater:
    • Sodium chloride (NaCl), Magnesium sulfate (MgSO₄), Calcium carbonate (CaCO₃).

  • Properties of Water

    • Hydrogen bonds create cohesion and affect properties like solubility, density, and specific heat capacity.
    • Definitions:
    • Solvent: dissolving agent; Solute: substance that is dissolved.
    • Solution: mixture of solute in solvent; Solubility: measure of solute's ability to dissolve.
    • Increasing temperature enhances salt solubility in water.
    • Salinity (average: 35 ppt) affected by run-off, precipitation, evaporation, and sea ice formation.
    • Salinity lowers freezing point of water.

  • pH and Gas Solubility

    • pH measures H⁺ concentration: average ocean pH is 8.2.
    • Indicators: litmus, universal indicator, pH probes.
    • O₂ solubility low; cold water holds more gases than warm water.
    • Gas solubility rises with increased atmospheric and water pressure (depth).

  • Density of Water

    • Density ( ext{Density} = rac{ ext{Mass}}{ ext{Volume}} ) changes with temperature and salinity.
    • Warm water is less dense and floats atop colder water.
    • Thermocline: layer where temperature decreases sharply with depth.
    • As salinity increases, density also increases.
    • Halocline describes significant salinity changes with depth.
    • Surface winds can induce turbulence affecting the mixing of surface water layers.

  • Objective 2: Earth’s Crust

    • Types: Oceanic (denser), Continental, Mantle, Core.
    • Theory of Plate Tectonics: 12 major plates float on the asthenosphere.
    • Evidence includes geological matching of rocks, fossil distributions, and paleomagnetic patterns at spreading centers.
    • Plate Boundaries:
    • Divergent: sea-floor spreading, mid-ocean ridges.
    • Convergent: trenches, volcanoes, earthquakes, tsunami.
    • Transform: earthquakes (e.g., San Andreas Fault).

  • Hydrothermal Vents

    • Vent waters are under pressure, hot, and mineral-rich.
    • Hydrothermal vent formation involves seawater seeping into cracks, heated by magma, creating a mineral-rich plume.

  • Sediment Dynamics

    • Weathering: breakdown of rocks (physical, chemical, biological).
    • Erosion: transport and relocation of rock materials.
    • Sedimentation: deposition of particles influenced by water flow and particle size.

  • Shoreline Morphology

    • Various shore types are formed via weathering, erosion, and sedimentation:
    • Rocky Shores: stable, many organisms, resistant to erosion.
    • Sandy Shores: unstable, burrowing organisms, gradual sloping.
    • Muddy Shores: least erosion, fine silt deposits, no slope.
    • Estuaries: brackish water regions, high turbidity.
    • Deltas: formed by river sediments at the mouth of rivers (e.g., Mississippi/Nile).

  • Oceanographic Phenomena

    • Tides: influenced by gravitational pull of the Moon/Sun.
    • Types include semi-diurnal and diurnal tides.
    • Spring Tide: maximum range during full/new moons.
    • Neap Tide: minimum range during quarter moons.
    • Currents: directed flow caused by environmental variables like wind and temperature.
    • Thermohaline Circulation: driven by temperature and salinity differences.
    • Ocean Conveyor Belt: deep-water circulation pattern.
    • Upwelling and Downwelling:
    • Upwelling: movement of cold, nutrient-rich water to the surface.
    • Downwelling: movement of dense cold salty water downward.

  • El Niño and La Niña

    • El Niño: occurs every 3-5 years, characterized by warmer water preventing upwelling, disrupting marine ecosystems (e.g., affects fishing).
    • La Niña: cold ocean current developing off the Ecuador coast, typically restoring the normal cold water flow and associated upwelling.