Plate Motions

Student Activities

Students will be modelling seafloor structures and continental plate motion using two landmasses separated by the sea. Specifically, they will:

• Use code to distribute organic and rock layers at equal elevations across two continents
• Use code to construct a sea floor ridge between the two continents
• Expand the ridge and add a fracture zone with magma.
• Dig a deep trench using simple code.

Fossil and Rock Distribution

Students are to use code to distribute coal (or the ore of their choice) and bone along the shore line of each continent at the same elevation to show that the continents were once connected. They will use the blocks replace with command to change sand into coal ore and gravel into bone.

This command will replace blocks relative to the player’s position. In the “from” sequence, the first number is the number of blocks left (+) or right(-) from the player. The second number is the player’s elevation, up (+) and down (-). The last number is the number of blocks forward (-) or back (+) from the player. For example . . .

• replace with coal ore
• when block is sand
• from 1 0 -1
• to -1 -1 1

. . . will replace sand with coal ore in a 3x3 square area.

Students should experiment with this and if errors are made, they just reverse the blocks and repeat the code.

Students are to replace some of the sand with coal ore (or ore of their choice) and some of the gravel with bone (fossils) at equal elevations on both continents.

Seafloor Ridge

Under the water, about half way between each continent students will find a trail of gold blocks. They are to use code to build a seafloor ridge ridge along the length of the trail using a shape command with a loop.

• sphere of (sand)
• center ~0 ~0 ~0
• radius 2
• [hollow]

If they wrap this with a repeat loop (10x) sand blocks will continue to fall behind them as they follow the path to the end. They can repeat this command until they have created a ridge.

Fracture Zone

Students should add a second ridge going in a different direction. As an added feature magma (lava) can be added to the top of the ridge.

Trenches

Use the blocks fill with command to create a long and deep trench on the ocean floor. Students should test it out on a small scale before attempting a larger trench. They should fill the trench with water.