Download - Continental Drift. Key Terms Continental Drift Mid-ocean ridge Sea-floor spreading Paleomagnetism
Continental Drift
Key Terms
• Continental Drift• Mid-ocean ridge• Sea-floor spreading• Paleomagnetism
Wegener’s Hypothesis
• Hypothesized continents once formed part of a single landmass called a supercontinent.
Science Needs Evidence
How do each of these strengthen the argument of Continental Drift?• Fossil evidence• Evidence from Rock Formations• Climatic Evidence• Mechanisms that cause movement• Mid-ocean ridges• Sea-floor spreading
Growth of the Atlantic Ocean
• The Atlantic ocean is spreading at a rate of 1 to 2 cm per year. How many years will it take for the sea floor of the Atlantic Ocean to spread 1 km?
Paleomagnetism
• Research and Explain each of the following: Please use diagrams with your explainations.
• Magnetic Reversals• Magnetic Symmetry
Prediction
• If the plates of the world are moving at an average rate of 2 cm per year, how many kilometers will the plates move in 2.5 X 108 years?
• Produce a map of the Earth and what it will look like 2.5 X 108 years from present. Map should include BOTH present and future locations of the continents and oceans.
• Use page 5 of your ESRT to determine current directional movement for each plate.
Questions
• 1. Describe the observation that first led to Wegener’s hypothesis of continental
drift.• 2. Explain how scientists know that Earth’s
magnetic poles have reversed many times during Earth’s history.
• 3. Identify how magnetic symmetry can be used as evidence of sea-floor spreading.
• 4. Explain how scientists date sea-floor rocks.
Questions
• 5. How does evidence that rocks farther from a ridge are older than rocks closer to the
ridge support the idea of spreading?• 6. Use the following terms to create a
concept map: continental drift, paleomagnetism, fossils, climate, sea-floor spreading, geologic evidence, supercontinent, and mid-ocean ridge.