enviro 4 Flashcards
Geology
Study of Earth’s physical features, processes, and history.
Convection
- Magma moves in convection cells.
- Hot, less dense material rises; cooler, denser material falls.
- Creates spreading zones and subduction zones.
Theory of Plate Tectonics:
Earth has 15 tectonic plates moving slowly over the surface.
Composed of the lithosphere (crust + upper mantle).
Most geological activity happens at plate boundaries.
Divergent Boundaries
Plates move away, creating new land.
Mid-ocean ridges
Underwater mountain ranges.
Rift valleys
Deep valleys where plates separate.
Convergent Boundaries
Plates move towards each other.
Subduction zones:
Dense plate pushed under lighter plate, forming trenches and volcanoes
compression
Continental plates collide, forming mountains.
Transform Faults
Plates slide past each other, causing earthquakes.
Hot Spots
Areas where molten mantle material reaches the lithosphere.
Volcanoes
Openings in Earth’s crust releasing magma, gas, and ash.
Locations of Volcanoes
Hot spots, divergent, and convergent boundaries.
Environmental Impacts of Volcanoes
Pros: Creates new land, fertilizes soil, provides materials.
Cons: Threatens lives/property, global cooling, CO₂ and SOx emissions, secondary disasters (earthquakes, tsunamis).
Earthquakes
Sudden plate movements releasing seismic waves.
Location of Earthquakes
All plate boundaries and fault lines.
Magnitude of Earthquakes:
Measured on the Richter scale.
Impacts of Earthquakes
Building collapse, toxic dust, disease spread, disruption of systems (water, food, energy).
Tsunamis
Large waves from ocean floor movements.
Causes of Tsunamis
Earthquakes, volcanic eruptions, landslides.
Impacts of tsunamis
Coastal flooding, infrastructure loss, water contamination, erosion, economic damage.
Weathering
Rocks breaking down due to air, water, chemicals, or organisms.
Erosion
Movement of rock fragments, later deposited elsewhere (deposition).
types of weathering
physical and chemical
Soil Structure
A mix of living and non-living material essential for life.
Formation Factors
Parent material, climate, organisms, topography, time.
Soil Horizons (Layers):
O Horizon: Organic matter (fresh/decomposed).
A Horizon: Topsoil, rich in nutrients, dark color.
E Horizon: Leaching layer (minerals move down).
B Horizon: Subsoil with clays and humus.
C Horizon: Weathered parent material.
R Horizon: Bedrock.
The Atmosphere Composition
78% Nitrogen, 21% Oxygen, 1% other gases (CO₂, Argon, Methane).
Layers of the atmosphere
Troposphere: Weather and clouds.
Stratosphere: Ozone layer.
Mesosphere: Coldest layer, burns meteorites.
Thermosphere: Aurora borealis, satellites.
Exosphere: Outermost layer.
Seasons
Caused by the sun’s angle.
Direct sunlight = summer (more heat).
Indirect sunlight = winter (less heat).
Albedo
High albedo = reflects more sunlight (cooler).
Low albedo = absorbs more sunlight (warmer).
Air Circulation Cells:
Hadley, Ferrel, Polar Cells drive wind and spread pollutants.
Rainshadow Effect:
Windward side = lush vegetation.
Leeward side = desert-like conditions.
Oceanic Currents
River-like ocean flows driven by density, wind, gravity.
effects of oceanic currents
Transport heat, nutrients, and pollutants.
Create upwellings (cold water rising to surface, rich in nutrients).
El nino
Pacific warming event.
Impacts: Warmer SW Americas, drought in Australia, weaker Atlantic hurricanes, fishing decline.
la nina
Pacific cooling event.
Impacts: Stronger Atlantic hurricanes, rain in Australia, drought in Americas.
