Plate Tectonics

Question 1

PLATE TECTONICS

Answer 1

• The theory explains the Earth’s crustal features
which result from the interaction of large rigid, moving crustal plates and other smaller plates.

Question 2

How did this theory come to be?

Answer 2

• In 1912, Alfred Wegener proposed that all the Earth’s continents were joined as a single landmass.
• In 1912, Alfred Wegener proposed that all the Earth’s continents were joined as a single landmass.
• He called this supercontinent PANGAEA
ALL LANDS
• Wegener proposed his idea as the Theory of Continental Drift.
• In this theory, he hypothesized that the continents have drifted apart and are still moving.

Question 3

What was his evidence for the theory?

Answer 3

• Wegener saw that the continents
shapes fit together like puzzle pieces.
What was his evidence for the theory?
• There was also matching fossils, continental rocks,
and crustal features across multiple continents.

Question 4

What do scientists of today know?

Answer 4

• Tectonic plates have been mapped by using
global markings of earthquakes and volcanoes.

Tectonic plates move due to
convection currents that occur in the asthenosphere!

Oceanic plates are thin and more dense.

Continental plates are thick and less dense.

Each plate moves at the rate that fingernails grow!

The average thickness of a plate is 100 km.

The plates are made up of the lithosphere.

The tectonic plates slowly move on top of the asthenosphere. This is a part of the mantle which is very hot, partially melted, and flows like thick putty.

Remember how the Earth
is made of many layers? Just look at the image to the left!
• Where the crust and mantle meet is where a lot of the action happens!

Question 5

In knowing the mechanism that moves the continents (convection), we now have the:

Answer 5

THEORY OF PLATE TECTONICS

Question 6

What happens where plates meet?

Answer 6

• A plate boundary is where plates
meet.
• How the plates move decide the
landforms that are made.

Question 7

There are THREE types of boundaries:

Answer 7

CONVERGENT DIVERGENT TRANSFORM

Question 8

At a CONVERGENT boundary, plates will:

Answer 8

COLLIDE

Question 9

Crustal Features made by
CONVERGENT boundaries include:

Answer 9

MOUNTAINS (FOLDED and VOLCANIC)
ISLAND ARCS OCEAN TRENCHES

Question 10

At a DIVERGENT boundary, plates will:

Answer 10

DIVIDE

Question 11

Crustal Features made by
DIVERGENT boundaries include:

Answer 11

MID-OCEAN RIDGES RIFT VALLEYS
 VOLCANOES

Question 12

At a TRANSFORM boundary, plates will:

Answer 12

SLIDE

Question 13

Crustal Features made by
TRANSFORM boundaries include:

Answer 13

FAULT LINES