enviro 4 Flashcards
(37 cards)
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
