From Biologic to Geologic Evolution Lets look at the Earth!
With Your Group: How does our new knowledge of refraction through different densities give us information about the earth?
Evidence From Earthquakes: P&S waves P (primary) waves= Compression (push/pull waves) S (secondary) waves= Transverse (up/down waves)
Mohorovicic (Moho) Discontinuity
Plate Tectonics Plate Boundaries and Interactions
The Theory of Plate Tectonics The Earth’s surface is divided into plates that move and interact with one another.
Overview of Plate Boundary Interactions
Divergent Plate Boundaries Plates are moving apart. New crust and lithosphere is “created” Associated with ocean ridges, rift valleys, volcanism, earthquakes and high heat flow.
Examples found on Earth: Mid-Atlantic Ridge, African Rift Valley, Iceland
Plates are moving towards each other. Old crust and lithosphere is “recycled”. Associated with ocean trenches, island arcs and mountain ranges. Earthquakes and volcanism are common. Convergent Plate Boundaries
Examples found on Earth: Himalayas, Pacific Ring of Fire, Andes Mountains, Marianas Trench
Plates slide past each other, oftentimes connecting two ridges or trenches. Crust is deformed or fractured; Lithosphere is neither created nor recycled. Long faults and earthquakes common. Examples found on Earth: San Andreas Fault Transform Plate Boundaries
Plate Boundaries, Earthquakes and Volcanic Activity
Continental Drift: Pangea
Matching Fossils
Matching Mountain Ranges
Glacial Evidence
Magnetism
Earthquake Patterns
Age of Rock
Hot Spots