Science Exam Term 3 2023

Question 1

What are the layers of the earth?

Answer 1

Crust, Mantle, Outer Core, Inner Core

Question 2

What is the composition of the crust?

Answer 2

It consists of oceanic and continental crust.

Question 3

What is the continental drift theory?

Answer 3

It is the theory that the continental landmasses are moving.

Question 4

Who created the continental drift theory?

Answer 4

Alfred Wegener.

Question 5

What is the shrinking earth theory?

Answer 5

It is the theory that mountain ranges, earthquakes and volcanoes are random.

Question 6

What was the evidence for continental drift?

Answer 6

Continents fit, Fossil correlation of africa and america, mountain correlation and climate data.

Question 7

What was evidence for plate tectonics?

Answer 7

Seafloor Spreading at mid ocean ridges.

Question 8

Explain the movement of plates in terms of convection currents.

Answer 8

The convection currents send hot magma upwards, and as it cools and descends, it drags the plates.

Question 9

Describe the features associated with the three types of plate boundaries and give examples of each.

Answer 9

Divergent, convergent and transform. Divergent is where two plates come apart, convergent is where two plates collide, transform is where they slide along each other. Divergent is constructive, convergent is destructive and transform is conservative.

Question 10

Describe and compare the processes of subduction and the formation of ocean ridges.

Answer 10

Subduction is where two plates collide at a convergent boundary and one is forced under the other.
Mid ocean ridges are formed from a divergent boundary.

Question 11

What is a hot spot? Example?

Answer 11

A hot spot is a denser and hotter part of the upper mantle where magma breaks through the surface and forms a volcano/mountain. Eg Hawaiian islands were formed from a hotspot.

Question 12

What is folding?

Answer 12

It is where pressure is exerted inwards from each side, occurs when earth is pliable.

Question 13

What is the difference between anticlines and synclines?

Answer 13

Anticlines: bending up
Synclines: bending down

Question 14

What is faulting?

Answer 14

It is displacement of once connected blocks of rock on a fault plane.

Question 15

What do the 3 types of faults mean?

Answer 15

Tension, NORMAL FAULT, where <- ->
Compression, REVERSE FAULT, where -> <-
Shearing, STRIKE SLIP FAULT, where ^ v

Question 16

Relate folding to the movement of tectonic plates and the formation of mountain ranges.

Answer 16

Mountains form where two continental plates collide. Since both plates have a similar thickness and weight, neither one will sink under the other. Instead, they crumple and fold until the rocks are forced up to form a mountain range.

Question 17

Explain the formation of faults in terms of the forces acting within the Earth’s crust and the movement of plates relative to each other

Answer 17

A fault is formed in the Earth’s crust as a brittle response to stress. Generally, the movement of the tectonic plates provides the stress, and rocks at the surface break in response to this.

Question 18

Relate the occurrence of major earthquakes and volcanoes to the movements along plate boundaries.

Answer 18

Most volcanoes and earthquakes happen along a convergent boundary between tectonic plates. Eg pacific ring of fire.

Question 19

What is the difference between lava and magma?

Answer 19

Magma is underground and lava is above ground.

Question 20

What do active, dormant and extinct volcanoes mean?

Answer 20

Active: erupting or recently erupted
Extinct: have not in 1000’s of years
Dormant: not erupted for 20+ years

Question 21

What is the difference between P-waves and S-waves?

Answer 21

P-waves travel through solid, liquid and gas, while S-waves only travel through solids.

Question 22

What is a surface wave?

Answer 22

These are slower than s-waves but are more destructive. Form when the earthquake occurs close to the surface.

Question 23

What is the difference between rayleigh and love waves?

Answer 23

Love waves are faster and cause shearing. Rayleigh waves travel as ripples and are slower.

Question 24

What is the difference between a seismograph and seismogram?

Answer 24

A seismogram is a record of the seismic waves from an earthquake, a seismograph is the measuring instrument that creates the seismogram.