READ: Important Vocabulary Terms

These are the most important vocabulary terms to learn this week. Please make sure you understand these terms. 

• Continental Drift: the gradual movement of the continents across the earth's surface through geological time.
  
• Bathymetry: the study of the ocean floor.
  
• Mid-ocean ridges: A long chain of mountains that rises up high above the deep seafloor. rift zones: In the middle of the mid-ocean ridges is a rift zone. The rift cuts the ridge into pieces. It is lower in elevation than the mountains of the mid-ocean ridge.
  
• Deep sea trenches: Trenches are found in the sea. Some are near the edges of continents. 
  
• Abyssal plains: Flat areas that may be dotted with volcanic mountains. 
  
• Guyots: Flat topped mountains that appear to have been eroded. Yet these mountains are thousands of feet below sea level.
  
• Continental margin: The transition from the land to the deep sea. The continental margin is made of continental crust. 
  
• Polar Reversals: When Earth’s magnetic pole switches positions. 
  
• Seafloor spreading is when hot magma rises up into the rift valley at the mid-ocean ridges. The lava cools to form new seafloor. Later more lava erupts at the ridge. The new lava pushes the seafloor horizontally away from the ridge. The seafloor moves! Seafloor spreading is what causes continents to move.
  
• Plate tectonics is the movement of the plates over Earth's surface.
  
• Plate boundaries are the edges where two plates meet. 
  
• Divergent plate boundaries: the two plates move away from each other.
  
• Convergent plate boundaries: the two plates move towards each other.
  
• Transform plate boundaries: the two plates slip past each other.
  
• Epicenter: the point on Earth’s surface directly above the place where an earthquake occurs.