Moving plates, and the clues that they move

Grade 6 Science Worksheet

Circle the best answer.

1. 1.

   Iceland sits on the Mid-Atlantic Ridge, where the land is slowly splitting apart. Which kind of boundary is Bo reading about?

   • Divergent
   • Transform
   • No boundary; Iceland is fixed
   • Convergent
2. 2.

   The Himalayas formed as India pushed into the rest of Asia. Which kind of boundary made them, in Esme's notes?

   • Divergent: plates pulling apart from each other
   • Convergent: two plates colliding
   • Transform: plates sliding past
   • A lava ocean pushing them up
3. 3.

   Map of California with the San Andreas Fault drawn and arrows on each side pointing in opposite directions along it. The San Andreas Fault in California is one of the few transform boundaries on land. What do its two plates do, by Jun's reading?

   • Pull apart to make a ridge
   • Push together into a trench
   • Sit still, since faults don't move
   • Slide past each other

4. Read this first

   Use this

   Map of an ocean floor colored in matching bands on both sides of a ridge in the middle; the color key runs from youngest to oldest.

5. 4.

   Kira's map of the ocean floor is colored by rock age, with a ridge down the middle. Where is the youngest seafloor rock?

   • Spread evenly everywhere
   • In the deepest trenches
   • At the ridge in the middle of the ocean
   • Near the coasts on each side of the ocean
6. 5.

   Cross-section, not to scale: a ridge with age labels increasing in both directions away from it. Seafloor rock gets older the farther it is from a mid-ocean ridge, on both sides. What does this show, according to Luz?

   • New seafloor forms at the ridge and spreads outward
   • The coasts make new seafloor
   • Old seafloor forms at the ridge
   • The seafloor stays put
7. 6.

   Map view of a ridge with matching light and dark stripes on each side, mirror images of each other. Magnetic stripes in the seafloor make the same pattern on both sides of a ridge, like a mirror. What does Milo conclude?

   • Each side formed at a different coast
   • Ocean currents painted the stripes
   • The seafloor formed at the ridge and spread both ways
   • The plates crashed together there
8. 7.

   2.5 cm each year; about 200,000,000 years; 100,000 cm = 1 km. Pangaea began to break up about 200 million years ago. Could 2.5 cm a year open an ocean thousands of kilometers wide in that time? Ren checks.

   • Yes, but just if plates move meters a year
   • No; the Atlantic has stayed this wide
   • No; centimeters are too small to add up
   • Yes: that adds up to about 5,000 km
9. 8.

   World map with earthquake and volcano dots crowded in lines around the Pacific Ocean. On a world map of earthquakes and volcanoes, the dots form lines around the edge of the Pacific Ocean. Why, by Tala's reasoning?

   • They mark the hottest places on the surface
   • They mark where the mantle is liquid lava
   • They mark where plates stand still
   • They mark plate boundaries
10. 9.

    Zee compares an earthquake map with a plate map. Where do most earthquakes happen?

    • In the middle of plates, far from the edges
    • Along plate boundaries, where plates grind and push
    • Evenly everywhere on Earth
    • Where plates float on liquid rock
11. 10.

    The Andes mountains have many volcanoes where an ocean plate sinks under South America. Which kind of boundary is Ari looking at?

    • Divergent
    • Convergent
    • Transform
    • A mid-ocean ridge