Lecture on Tidal Ranges and Energy in the Bay of Fundy

Overview of Tidal Ranges

• Tidal Range: Difference between high and low tide.
• Units: Measured in meters.
• Local Tidal Range: 3 meters or approximately 9 feet.
• Bay of Fundy: Has the largest tidal range in the world, about 15 meters or 45-50 feet.

Bay of Fundy Specifics

• Location: Eastern coast of Canada, between New Brunswick and Nova Scotia.
• Length: 270 kilometers.
• Tidal Phenomenon:
  • Average global tidal difference: 1 meter.
  • Bay of Fundy tidal difference: 14 meters over 6 hours and 13 minutes.
  • Moves 160 billion metric tons of water.

Causes of Large Tidal Ranges

• Gravitational Pull: Mainly by the moon, less by the sun.
• Seishing: Natural oscillation of water in basins, influenced by size, shape, and timing.
  • Resonance: Bay's oscillation aligns with tidal cycle, amplifying the effect.
  • Funnel Shape: Bay narrows and shallows at northern end, increasing tidal impact.

Energy Harnessing

• Current Method: Tidal power plant with a barrage across an inlet.
  • Water stored and released to spin turbines.
  • Issues: Inefficient, harmful to marine life.
• Future Developments:
  • Tidal turbines on ocean floor.
  • Use water flow like wind turbines.
  • Concept termed as "lunar power."

Reversing Falls and Slack Tide

• Reversing Falls: Feature related to high tidal ranges.
• Slack Tide: Transition period between high and low tide, crucial for navigation.

Tidal Bores

• Definition: A wall of water moving up a river due to incoming tide.
• Examples:
  • Amazon River:
    • Waves up to 15 feet high.
    • Travel 500 miles inland, speeds of 15 miles per hour.
    • Known locally as Pororoca.
  • Brazilian Surfers:
    • Ride waves for extended periods.
    • Pororoca considered a national pride.

Conclusion

• Key Concept: Understand the factors that contribute to tidal ranges and how they can be harnessed for energy.
• Questions to Consider: What are slack tides? How do tidal bores form? How can we improve tidal energy systems?