LESSON 5: Plate Boundaries Processes

Plate Boundaries

• Definition: The area where two tectonic plates meet. (Text from the transcript notes: "What is a plate boundary? The area where two tectonic plates meet continental crust trench").

• Key ideas across the slides: different boundary types (convergent, divergent, transform); landforms formed; processes along boundaries; examples; relevance to disasters; group activities and assessment rubrics; religious and community context interwoven with science content.

Convergent Boundaries

• Description: two plates push toward each other; one plate may sink beneath the other (subduction) or both may crumple to form mountains.

• Q&A reference: "Which plate boundary is present when one plate may sink beneath the other? Convergent".

• Subtypes:

  • Continental-Continental: intense folding and faulting; broad folded mountain ranges; no subduction; shortening and thickening of plates within the collision zone; example: Himalaya Range.

  • Oceanic-Continental: oceanic plate sinks beneath continental plate; causes trenches, volcanic arcs; example mentions Nazca Plate under South American Plate context in the slides.

  • Oceanic-Oceanic: one oceanic plate subducts under another; creates trenches and volcanic island arcs; example: Aleutian Islands.

• Landforms and processes:

  • Mountain ranges (e.g., Himalayas) due to continental-continental collision.

  • Trenches and volcanic arcs in oceanic-continental and oceanic-oceanic collisions.

  • Shortening and thickening of crust in collision zones.

• Examples mentioned:

  • Himalaya Range (Continental-Continental).

  • West coast of South America (Nazca Plate subducting under South American Plate; Oceanic-Continental).

  • Aleutian Islands (Oceanic-Oceanic).

• Significance:

  • Creates high mountain belts, deep trenches, and explosive volcanism in associated arcs.

  • Linked to seismic activity (earthquakes) due to subduction and compression.

Divergent Boundaries

• Description: two plates move apart from each other; new crust is formed as magma rises to fill the gap.

• Key concept: Sea Floor Spreading creates new oceanic crust.

• Landforms and processes:

  • Mid-ocean ridges (submarine mountain ranges) such as the Mid-Atlantic Ridge.

  • Rift valleys and volcanic activity along spreading centers.

• Examples mentioned:

  • Mid-Atlantic Ridge (oceanic-oceanic boundary) cross Iceland; North Atlantic context; also South Atlantic boundary between South American and African Plates.

  • Red Sea and East African Rift (continental-continental spreading examples).

• Important note from slides:

  • Rising convection currents beneath the lithosphere lift the lithosphere, producing mid-ocean ridges and volcanic activity.

• Resulting crust:

  • Sea floor spreads, creating new oceanic crust.

Transform Boundaries

• Description: two plates slide horizontally past each other; do not create or destroy crust.

• Characteristics:

  • Most transform faults are found in the ocean basin and connect offsets in mid-ocean ridges.

• Examples mentioned:

  • Boundary between Pacific Plate and North American Plate along California.

• Significance:

  • Causes earthquake activity due to friction as plates move past one another.

Oceanic vs Continental (Convergent Subtype)

• Definition: subduction occurs where an oceanic plate sinks beneath a continental plate.

• Landforms and processes:

  • Formation of trenches at the subduction zone.

  • Volcanic arcs on the continental crust due to melting of the subducting slab.

• Examples mentioned:

  • Nazca Plate beneath the South American Plate (Andean region).

  • Washington-Oregon coastline context as a boundary example in the region.

Oceanic vs Oceanic

• Definition: subduction occurs when one oceanic plate is forced under another.

• Landforms and processes:

  • Deep trenches; volcanic island arcs forming above the subduction zone.

• Examples mentioned:

  • Aleutian Islands as an example of an oceanic-oceanic convergence with island arc volcanism.

Continental vs Continental

• Definition: two continental plates collide with no subduction; crust is thickened and deforms rather than subducting.

• Landforms:

  • Broadfolded mountain ranges (e.g., Himalayas) due to compression and crustal shortening.

• Significance:

  • Major tectonic uplift and mountain-building events; relatively less volcanic activity compared to oceanic subduction zones.

Landforms, Processes, and Their Significance

• Key landforms produced at plate boundaries:

  • Mountain ranges (continental-continental collision)

  • Trenches (subduction zones, particularly oceanic-continental and oceanic-oceanic)

  • Mid-ocean ridges (divergent boundary, oceanic-oceanic)

  • Rift valleys (divergent boundaries, continental crust)

  • Volcanic arcs/islands (subduction boundaries; associated with volcanic activity)

• Core processes:

  • Subduction (oceanic crust sinks beneath another plate)

  • Crustal shortening and thickening (continental-continental collision)

  • Sea floor spreading (creation of new oceanic crust at divergent boundaries)

  • Faulting and fault offsets (transform boundaries)

Objectives (from the slides)

• a. Describe and explain the different processes that occur along plate boundaries creating landforms such as mountain ranges, trenches, etc.

• b. Demonstrate the formation of different landforms at divergent, convergent, and transform boundaries through group presentations.

• c. Justify the importance of studying plate boundaries in mitigating effects of disasters.

Group Work: Webquest (Activity Outline)

• 1) Each group will have an assigned plate boundary.

• 2) Groups will search for the description, real-life examples, and processes along the assigned plate boundaries (landforms during movements).

• 3) Each group must have a creative presentation about the plate boundaries (poem, skit, gram acrostic, etc.).

• 4) Fifteen minutes will be allotted for the activity.

• 5) Each group will choose presenters to show their work.

Data and Collaboration Rubric (Content Quality)

• Content Quality of Data (10 pts):

  • Included data are important. No major details are excluded. $10\ \text{pts}$

• Validity of Data (10 pts):

  • All data included are correct and valid. $10\ \text{pts}$

• Cooperation (10 pts):

  • Evidence of collaboration among family members; all voices included in the planning process. $10\ \text{pts}$

• Grading scale excerpts:

  • 1-3 pts: 11 or more major data are excluded or too many trivial data are included.

  • 4-6 pts: 5-10 major data are missing or some data are trivial.

  • 7-9 pts: 1-4 major data are missing or some data are incorrectly presented.

  • 10 pts: All data are included, correct, and well-presented.

Practice Questions and Review Prompts (From Slides)

• Which plate boundary is the reason for the formation of these? 1 2 3 (Answer shown later as convergent for certain formations.)

• Which plate boundary is present when one plate sinks beneath the other? Convergent.

• What do you call a boundary where two plates slide horizontally past each other without creating or destroying crust? Transform.

• What is a plate boundary? The area where two tectonic plates meet; examples include trenches and continental crust interactions.

• Which boundary makes new crust? Divergent (Sea Floor Spreading).

• What landforms are typical of divergent boundaries? Mid-ocean ridges, rift valleys, new oceanic crust.

Summary of Key Boundary Examples (as presented in slides)

• Convergent: Himalaya Range (Continental-Continental); Andes/Nazca subduction (Oceanic-Continental); Aleutian Islands (Oceanic-Oceanic).

• Divergent: Mid-Atlantic Ridge (Oceanic-Oceanic); Red Sea and East African Rift (Continental-Ocean/Continental-Continental contexts).

• Transform: California fault system (Pacific Plate vs North American Plate).

• Oceanic vs Continental: trenches and volcanic arcs (subduction zones).

• Oceanic vs Oceanic: island arcs and trenches (e.g., Aleutians).

Bible Verse and Marian Context (Interwoven with science content)

• Bible Verse of the Day: Psalm 95:4-5

  • "In his hand are the depths of the earth, and the mountain peaks belong to him. The sea is his, for he made it, and his hands formed the dry land."

• Closing and devotional elements:

  • Science Talks

  • Mary, Guide of the Way; Ignacian Marian Community advocates for: Excellence, Nationalism

  • Closing Prayer: Glory be to the Father, and to the Son, and to the Holy Spirit. Amen. Mary, Guide of the Way, Pray for us. Venerable Ignacia Del Espiritu Santos, Pray for us.

  • Final affirmation: All for GOD… to GOD.

Administrative and Support References in the Slides

• Parent Hotline prompt: "How can you help in conserving/preserving our natural resources such as landforms in our country?" (Encourages community involvement and stewardship.)

• Next meeting goal: To facilitate the discussion next meeting, look for Science Investigatory Projects made within 5 years and be inspired by how the introduction was made.

• Closing notes: All content emphasizes faith-based community values along with science education.

Quick Q&A (From the Slides)

• Plate boundary type for a given landform scenario (as depicted):

  • Convergent boundary commonly associated with mountain building and trenches.

  • Divergent boundary associated with sea-floor spreading and ridge formation.

  • Transform boundary associated with horizontal sliding and transform faults.

Key Equations and Notation (LaTeX)

• No explicit numerical equations were provided in the slides; the following helpful representations summarize concepts:

• Plate boundary concepts can be expressed as boundary types B ∈ {Convergent, Divergent, Transform} with associated processes P(B):

  • Convergent: subduction, uplift, mountain-building; associated with trenches and volcanic arcs.

  • Divergent: sea-floor spreading, ridge formation, crustal creation; rift valleys.

  • Transform: lateral sliding, faulting; seismic activity.

• For rubric scores (example):

  • Content Quality of Data: $10 \text{ pts}$

  • Validity of Data: $10 \text{ pts}$

  • Cooperation: $10 \text{ pts}$

End of Notes