fv1 - tectonic plates

AP Environmental Science: Unit 4 – Earth Systems & Resources

Topic: 4.1 Tectonic Plates

Page 1: Types of Tectonic Boundaries

• Convergent Boundaries

  • Definition: Two tectonic plates move towards each other (-> <-).

  • Characteristics:

    • More dense plate subducts under the less dense plate.

    • Example: Mariana Trench.

  • Structures Formed:

    • Between oceanic plates: island arcs, oceanic trenches.

    • Between oceanic and continental plates: mountains, volcanoes.

• Divergent Boundaries

  • Definition: Two tectonic plates move apart from each other (<-->).

  • Characteristics:

    • Creates visible fault lines, rift valleys, seafloor spreading, and volcanoes.

    • Examples: East Africa Rift Valley, Mid-Atlantic Ridge, East Pacific Rise.

  • Seafloor Spreading:

    • Magma rises through the gap between plates, cools, and forms new rock.

• Transform Boundaries

  • Definition: Two tectonic plates slide past each other (🔼 🔽).

  • Characteristics:

    • Often causes earthquakes due to friction and energy buildup.

    • Example: San Andreas Fault in California.

Page 2: Understanding Plate Tectonics

• Plate Tectonics Map

  • Importance: Analyzing maps helps geologists understand tectonic movements and landforms.

  • Example: The Ring of Fire in the Pacific Ocean illustrates volcanic activity related to plate movements.

  • Application: Predicting natural disaster prevention strategies based on fault line events.

Page 3: Influence on Urban Planning and Disaster Preparedness

• Transform Boundaries and Urban Planning

  • Influence on strategies in seismically active regions.

  • Key Terms:

    • Convergent Boundary: Collision of plates leading to mountains, volcanic activity, and earthquakes.

    • Divergent Boundary: Plates moving apart, creating new crust from rising magma.

    • Earthquakes: Sudden ground shaking from tectonic movement.

    • Rift Valleys: Formed by plates moving apart, characterized by steep walls.

    • Subduction: One plate moves beneath another, recycling crust into the mantle.

    • Transform Boundary: Plates slide past each other, causing earthquakes.

    • Volcanoes: Openings for magma and gases to erupt, formed by tectonic activity.

• Impact of Transform Boundary Studies

  • Vertical land movement is a primary concern along transform faults.

  • Some transform boundaries are becoming inactive, reducing seismic preparedness needs.

  • Development of stricter building codes and improved earthquake early warning systems.

  • Abandonment of major cities near transform boundaries is not a common practice.