unit 3 vocab

123456789101112
Across
  1. 2. Boundary created when plates move away from each other
  2. 3. a seamount whose top has been eroded flat by wave action, and then subsides
  3. 5. Boundary created when plates move towards each other
  4. 7. Slope the steep decline from the continental shelf to the ocean floor
  5. 8. Boundary created when plates slide past each other
  6. 9. a long, narrow, deep depression on the ocean floor
  7. 11. the solid upper layer of the Earth's mantle, that is so hot that it behaves plastically and can flow. Convection currents occur here and move the lithospheric plates above.
  8. 12. an underwater mountain, usually volcanic
Down
  1. 1. Ridge a long underwater mountain chain, produced by seafloor spreading at divergent plate boundaries
  2. 4. top-most layer of the Earth, composed of both the crust and the portion of the upper mantle that behaves as a brittle, rigid solid
  3. 5. Shelf the gently sloping part of the continent that is underwater
  4. 6. Valley an undersea valley, located along the center of the mid-ocean ridge, from which lava seeps out and creates new ocean floor.
  5. 9. Current an underwater mudslide of sediments
  6. 10. Rise a mound of sediments at the base of the continental slope