3.1.1:Tectonic processes+hazards

Question 1

Asthenosphere

Answer 1

The top solid top of layer of the mantle

Question 2

Lithosphere

Answer 2

The uppermost mantle

Question 3

Mantel

Answer 3

Composed mainly of silicate rocks in a semi-molten state. Between the core and the lithosphere.

Question 4

Core

Answer 4

The centre of the earth consisting of iron and nickel.

Question 5

Oceanic crust

Aka sima

Answer 5

A later consisting of mainly basalt which is in the sea and denser (than the continental crust)

Question 6

Continental crust

Aka sial

Answer 6

Above sea composed largely of granite.

Question 7

Convection currents

Answer 7

Heat rises in the core then cools and falls

Question 8

Moho discontinuity

Answer 8

Area between the crust and the mantel

Question 9

Converging current

Answer 9

Pushes plates together

Question 10

Diverging current

Answer 10

Pulls plates apart

Question 11

Ridge push

Answer 11

At a mid-ocean ridge molten magma rises, cools= more dense, old ridge slides away (repeat)

Question 12

Slab Pull

Answer 12

Force the edge of a subducting plate exerts on the rest of the plate causing it to sink with it

Question 13

Constructive plate margin

2 types

Answer 13

• 2 plates oceanic crust, diverge
  or
• 2 plates continental crust, diverge

Question 14

Destructive plate margin

Answer 14

-2 plates oceanic crust, subduction occurs
or
-oceanic to continental, subduction occur for oceanic plate

Question 15

Collision plate margin

Answer 15

2 continental plates

former ocean sediments forced upwards = mountains

Question 16

Conservative (transform) margin

Answer 16

2 plates move laterally past each other = transform movement

Question 17

4 types of plate margin?

Answer 17

• constructive
• destructive
• collision
• conservative/transform

Question 18

Hotspots

Answer 18

Small areas with unusually high heat flow

(found away from plate boundaries)

Question 19

Oceanic hotspots

Answer 19

Plumes of magma rise from the astenosphere and rise to the surface as a volcanic eruption if crust is weak or thin

Question 20

Sea mounts

Answer 20

extinct underwater volcanoes

Question 21

Intra-plate earthquakes

Answer 21

Caused by stresses in crustal rock, usually movement along ancient fault lines

Question 22

Earthquakes caused by human activities

2

Answer 22

• Fracking

- Weight of water held back by a dam caused earthquake in India, 1993

Question 23

Fracking

Answer 23

Extraction of shale gas by pumping high pressure water into the ground can cause earthquakes

Question 24

Fracking example?

Answer 24

Fracking in Lancashire, UK halted in 2015 due to large earthquakes in Blackpool

Question 25

Types of lava

2

Answer 25

Depending on crust type:
Balsaltic lava
Rhyolitic (acidic) lava

Question 26

Balsaltic lava

Answer 26

Oceanic crust melts to form balsaltic lava

Question 27

Rhyolitic (acidic) lava

Answer 27

Continental crust melts to form rhyolitic lavas with a high silica content

Question 28

High silica content in lava?

Answer 28

thick, high viscosity

Question 29

Low viscosity?

Answer 29

Runs easily

Question 30

Effusive?

Answer 30

When lava gently flows out of a volcano

Question 31

Explosive?

Answer 31

When lava violently erupts from a volcano