Plate Tectonics

Question 1

What are the 6 layers of the earth?

Answer 1

-crust
-outer core
-inner core
-mantle
-lithosphere
-Asthenosphere

Question 2

What is the core?

Answer 2

-the centre of the earth
-split into an inner core and an outer core
-inner core is a solid call containing iron and nickel
-outer core is semi-molten and also contains iron and nickel

Question 3

What is the mantle?

Answer 3

-the bit around the core
-mostly made of silicate rocks
-part of the mantle nearest the core is quite rigid
-the layer above this is called the asthenosphere and is semi-molten
-the very top bit is quite rigid

Question 4

What is the crust?

Answer 4

The outer layer of the earth

Question 5

What is the lithosphere?

Answer 5

The rigid top part of the mantle and the crust together

Question 6

What are the 2 types of crust?

Answer 6

-continental
-oceanic

Question 7

What is continental crust?

Answer 7

-thick (30-70km)
-less dense than oceanic

Question 8

What is oceanic crust?

Answer 8

-thinner (6-10km)
-more dense

Question 9

What are plate margins/plate boundaries?

Answer 9

Places where the plates meet

Question 10

What are convection currents?

Answer 10

-lower parts of the asthenosphere heat up, become less dense and slowly rise
-as they move towards the top of the asthenosphere they cool down, become more dense and slowly sink
-these circular movements of semi-molten rock are called convection currents

Question 11

What is slab pull?

Answer 11

-at destructive plate margins
-denser crust is forced under less dense crust
-the sinking of the plate edge pulls the rest of the plate towards the boundary

Question 12

What is ridge push?

Answer 12

-constructive plate margins, magma rises to the surface and forms new crust, which is very hot. It heats the surrounding rocks, which expand and rise above the surface of the surrounding crust, forming slope
-the new crust and becomes denser, gravity causes the denser

Question 13

How does sea floor spreading occur?

Answer 13

-tectonic plates diverge, magma rises up to fill the gap created, then cools to form new crust
-over time, the new crust is dragged apart and even more new crust forms between it
-when this happens at a plate margin under the sea the sea floor gets wider

Question 14

What types of hazards occur at constructive plate margins?

Answer 14

Earthquakes
Volcanoes

Question 15

What types of hazards occur at destructive plate margins?

Answer 15

Earthquakes
Volcanoes

Question 16

What types of hazards occur at conservative plate margins?

Answer 16

Earthquakes

Question 17

What is a constructive plate margin?

Answer 17

-plates are diverging, creating land

Question 18

What is a destructive plate margin?

Answer 18

-plates are converging destroying the land

Question 19

What is a conservative plate margin?

Answer 19

-plates are moving past each other

Question 20

How do volcanoes occur at constructive plate margins?

Answer 20

-mantle is under pressure from the plates, the plates moving apart releases pressure at the margin
-release of pressure causes the mantle to melt, producing magma
-magma is less dense than the plate above so it rises and can erupt to form a volcano

Question 21

How do earthquakes occur at constructive plate margins?

Answer 21

-some plates move faster than others
-causes pressure to build up
-when the pressure becomes too much the plate cracks, making a fault line and causing an earthquake

Question 22

What types of landforms are formed at constructive plate margins?

Answer 22

Rift valleys
Ocean ridge