Earthquakes, Soil, Atmosphere, and Climate Notes

Earthquakes and Plate Boundaries

  • Earthquakes occur when plates rub against each other, building up pressure, energy, and stress.
  • The release of this energy causes the Earth's crust to shake.

Soil Formation

  • Soil is formed from parent material and humus.
  • Parent material: Weathered rock.
  • Humus: Decayed organic matter.
  • Weathering of rock leads to sediment formation, which undergoes erosion, transportation, and deposition.
  • This sediment (parent material) combines with humus to form soil.

Humus and Soil Horizons

  • Humus consists of leftover organic matter from dead organisms.
  • In a soil profile, the top horizon contains the most humus, while the bottom horizon has the most parent material.

Soil Erosion and Water Quality

  • Soil is easily eroded, which can harm water quality.
  • Soil in water degrades the quality.
  • Soil also filters and cleans water as it infiltrates; pollutants stay in the soil, resulting in cleaner groundwater.

Water Holding Capacity and Particle Size

  • Water holding capacity: The amount of water soil can retain.
  • Different soils have different water-holding capacities.
  • Particle size determines soil's porosity and permeability.

Soil Texture Triangle

  • The soil texture triangle relates the percentages of sand, silt, and clay in a soil sample.
  • Particle sizes: Sand, silt, and clay.
  • By finding the intersection of the percentages of each particle size on the triangle, the soil type can be determined (e.g., sandy clay loam, clay loam, silty loam).

Earth's Atmosphere

  • The Earth's atmosphere is mostly nitrogen and oxygen.
  • Nitrogen is more abundant than oxygen.

Layers of the Atmosphere

  • The layers of the atmosphere are:
    • Troposphere
    • Stratosphere
    • Mesosphere
    • Thermosphere
  • Each layer is characterized by temperature fluctuations.
    • Temperature decreases in the troposphere.
    • Temperature increases in the stratosphere.
    • Temperature decreases in the mesosphere.
    • Temperature increases in the thermosphere.

Global Wind Patterns

  • The Equator receives the most direct solar radiation, leading to high evaporation rates.
    • Warm, moist air rises, cools, condenses, and forms clouds, resulting in high rainfall at the Equator and rainforests.
  • Convection currents (e.g., Hadley cell) distribute moisture away from the Equator.
    • At around 30 degrees latitude (north and south), the air sinks creating high pressure.
    • High pressure inhibits evaporation, leading to desert formation at these latitudes.

Circulation Cells and the Coriolis Effect

  • Circulation cells: Hadley cell, Ferrell cell, and polar circulation cell.
  • Coriolis effect: The Earth's rotation deflects wind direction, creating wind systems at various latitudes.
  • Wind systems:
    • 0-30 degrees: Trade winds
    • 30-60 degrees: Westerlies
    • 60-90 degrees: Polar easterlies

Watersheds or River Basins

  • A watershed is an area of land where all streams and tributaries drain into a common river.
  • Factors impacting watersheds:
    • Land area
    • River length
    • Slope (higher slope = faster water flow)
    • Soil and vegetation

Solar Radiation

  • Incoming solar radiation is the primary energy source for the Earth.
  • The angle of solar radiation determines the amount of energy received.
    • The Equator receives the most solar radiation due to its direct angle to the sun.
    • Solar radiation decreases with increasing distance from the Equator.
  • Seasonal variation in solar radiation:
    • Summer: Long days, high solar radiation.
    • Winter: Short days, low solar radiation.
  • The Earth is tilted on its axis at 23.5 degrees, causing varying amounts of daylight and the seasons.

Weather vs. Climate

  • Weather: Short-term atmospheric conditions.
  • Climate: Long-term temperature and precipitation patterns (over 30 years).

Factors Impacting Climate

  • Degree of solar radiation.
  • Geography, such as the rain shadow effect: Mountains block moist air, causing rainfall on one side and desert conditions on the other.

El Nino and La Nina

  • El Nino: Trade winds weaken, causing warm water to accumulate near North and South America.
    • This warms and moistens the Americas and blocks upwelling (the rise of nutrient-rich water).
    • Blocked upwelling is bad for fish (no nutrients), harming the fishing industry.
    • Asian Australia experiences cool, dry conditions, potentially leading to drought.
  • La Nina: The opposite of El Nino; trade winds strengthen, pushing warm water to Asia and Australia, causing warm, wet conditions there.
    • North and South America become cool and dry.
  • El Nino can increase rainfall in North and South America, which may be good for farming but bad for fishing due to blocked upwelling.