Tectonic Plates 🗺️

Question 1

What is a tectonic plate?

Answer 1

The earth’s crust divided into slabs that float in the mantle

Question 2

What are the 2 crusts plates are made of?

Answer 2

Continental - thick, less dense (30-50km)

Oceanic - thinner, more dense (5–10km)

Question 3

What are the 3 types of plate margin?

Answer 3

• destructive ➡️⬅️
• constructive ⬅️➡️
• conservative ⬇️⬆️

Question 4

What happens at a destructive plate boundary?

Answer 4

• plates move towards each other
• oceanic plate meets a continental plate, denser oceanic plate is sub-ducted and destroyed, creating magma
• volcanoes and oceanic trench occur here
• when 2 continental plates collide, fold mountains form

Question 5

What happens at constructive plate boundary?

Answer 5

• two plates move away from each other
• magma rises from mantle to fill gap and cools, creating new crust
• volcanoes

Question 6

What happens at conservative plate boundary?

Answer 6

• plates move sideways past each other, or are moving in same direction at different speeds
• crust isn’t created or destroyed
• earthquakes

Question 7

What is the place where plates meet called?

Answer 7

Plate margins/boundaries

Question 8

Where do volcanoes occur?

Answer 8

Destructive and constructive boundaries

Question 9

How are volcanoes formed at destructive boundaries?

Answer 9

Denser oceanic plate moves down into the mantle, where it melts
Pool of magma forms, rises through cracks in crust
Magma erupts, forming a volcano

Question 10

How are volcanoes formed at constructive boundaries?

Answer 10

Magma rises up into gap created by plates moving apart, forming a volcano

Question 11

Where do earthquakes occur?

Answer 11

All three plate margins

Question 12

How are earthquakes formed at destructive boundaries?

Answer 12

Tension builds when one plate gets stuck as it moves past each other

Question 13

How are earthquakes formed at constructive boundaries?

Answer 13

Tension builds along cracks in the plates as they move away from each other

Question 14

How are earthquakes formed at conservative boundaries?

Answer 14

Tension builds up when plates that are grinding past each other get stuck

Question 15

What happens to create an earthquake after tension?

Answer 15

• plates jerk past each other, sending shock waves - vibrations are the earthquake
• shock waves spread out from focus - where quake starts
• waves are strong near the focus and cause more damage
• epicentre is right above the focus, very dangerous

Question 16

How are earthquakes measured?

Answer 16

Richter scale - scale from 1 (nothing) — 12 (dangerous)
Logarithmic - each number is increasing by 10 times as much ground shaking