The Structure Of The Earth and plate boundaries

Question 1

Name the lithosphere

Answer 1

👉🏻Oceanic crust and continental crust
👉🏻Crust
👉🏻Uppermost mantle - cooled mantle 
👉🏻Asthenosphere - slightly cooler than the mantle; found above the mantle
👉🏻Mantle - hot, molten rock

Question 2

What are convection currents?

Answer 2

Convection currents are the currents or movement of the mantle. The mantle is heat and rises upwards then cools when it reaches the crust. When it is cooler it sinks back down to be heated again by the core. The process continues; round and round.

Question 3

Name 2 effects that convection currents have on the earth:

Answer 3

They push plates together (create fold mountains ⛰); pull plates apart (create volcanoes 🌋); cause earthquakes etc.

Question 4

Name three features of continental crusts and oceanic crust:

Answer 4

Continental:
• less dense than oceanic
• does not sink
• between 25 - 100km thick 
• very old (between 3 - 4 billion years old) 
• cannot be destroyed

Oceanic crust:
• 5 - 10km thick
• dense
• sinks into the mantle where the oceanic and continental plates meet.
• newer than the continental crust (not as old)
• Is constantly forming at constructive margins
• It can be destroyed and created

Question 5

Name the different plate boundaries:

Answer 5

Destructive
Collision
Constructive
Conservative

Question 6

What is a destructive plate boundary?

Answer 6

This is where the convection currents push the plates together and the oceanic plate is forced underneath the continental and melts. Friction builds between the two plates and can cause sever earthquakes.

Question 7

What is a constructive plate boundary?

Answer 7

This is where convection currents pull the plates apart leaving a gap. Magma rises up through this gap (a volcano) and builds new land. This usually happens under the ocean.

Question 8

What is a conservative plate boundary?

Answer 8

This is where two plates slide against each other. They move in the same direction alongside each other however one moves faster than the other. Sometimes these plates can get stuck consequently causing friction and pressure to build. This build of pressure is eventually released when the two plates slip. Often this release of pressure can lead to earthquakes.

Question 9

What is a collision plate boundary?

Answer 9

A collision plate boundary is where two plates are pushed into each other by convection currents. When these plates meet they are pushed up and create what are know as mountains.