Week 3: Plate tectonics

Question 1

Layer of earth that consists of plate tectonics

Answer 1

Lithosphere

Question 2

The scientific method

Answer 2

1. Observe
2. Hypothesise
3. Predict
4. Test predictions
5. Repeat, repeat, repeat

Question 3

A scientific hypothesis is only credible if it is

Answer 3

Capable of being tested and proven wrong

Question 4

Sea floor spreading hypothesis

Answer 4

1. Ocean floor sediment thickens away from mid-ocean ridges
2. New crust moves away from ridges and gathers sediment
3. Earthquakes and high heat flow at mid-ocean ridges > seafloor spreading forms new crust at mid ocean ridges
4. At trenches, sea-floor dives back into the mantle
5. Mechanism for continental drift

Question 5

Primary waves travel fast through what temperature material

Answer 5

Cold

Question 6

Do primary or secondary waves travel liquid

Answer 6

Primary liquid

Question 7

Earths interior strength layers

Answer 7

Lithosphere = strong, cool, rigid
Asthenosphere = high temperature, weak, easily deformed, solid
Mesosphere = high temperature and pressure, strong solid

Question 8

Mantle is made of

Answer 8

Solid rock that deforms in a ductile (plastic) way when at high pressures and temperatures

Question 9

How heat is transferred from earths interior towards the surface

Answer 9

Convection

Question 10

Heat is transferred from the convecting asthenosphere to the non-convecting lithosphere by

Answer 10

Conduction

Question 11

Plate boundaries where plates move apart and have shallow earthquakes

Answer 11

Divergent

Question 12

Examples of divergent plates

Answer 12

1. Mid ocean ridges
2. Continental rifts

Question 13

Mid ocean ridge formation

Answer 13

1. Plates pull apart
2. Asthenosphere wells up to fill gap, melting to produce magma
3. Magma cools, creating new oceanic crust (basalt/gabbro)
4. Normal fault scarps

Question 14

Types of faults

Answer 14

1. Normal fault (block above fault moves down)
2. Reverse fault (block above the fault moves up)
3. Strike-slip fault (blocks move side by side, no vertical movement)
4. Oblique fault (mix between normal and strike slip)

Question 15

Plate boundaries where plates move together resulting in reverse faults

Answer 15

Convergent

Question 16

Examples of convergent plates

Answer 16

1. Subduction zones
2. Continental collision zones

Question 17

Plate boundaries where plates slide against each other

Answer 17

Transform

Question 18

Examples of transform faults

Answer 18

Alpine fault

Question 19

Two types of continental margins

Answer 19

1. Active margins (coincide with plate boundaries)
2. Passive margins (far from plate boundaries

Question 20

Do passive or active continental margins have wider continental shelves

Answer 20

Passive margins

Question 21

Continental margins migrate with

Answer 21

Sea level