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?

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

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

   • Transform: plates sliding past
   • Divergent: plates pulling apart from each other
   • Convergent: two plates colliding
   • 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?

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

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
   • Near the coasts on each side of the ocean
   • In the deepest trenches
   • At the ridge in the middle 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?

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

   2.5 cm each year; 100 years. The Mid-Atlantic Ridge spreads about 2.5 cm a year (USGS). How much wider does the Atlantic get in 100 years, by Noah's math?

   • About 250 km
   • About 2.5 cm
   • About 2.5 m
   • No wider
8. 7.

   2.5 cm each year; 1,000,000 years; 100,000 cm = 1 km. At about 2.5 cm a year, how far does the Atlantic widen in 1 million years? Pia works it out.

   • About 2.5 km
   • About 2,500 km
   • About 25 m
   • About 25 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 where plates stand still
   • They mark where the mantle is liquid lava
   • They mark plate boundaries
   • They mark the hottest places on the surface
10. 9.

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

    • Along plate boundaries, where plates grind and push
    • Evenly everywhere on Earth
    • In the middle of plates, far from the edges
    • 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?

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