Hazards resit

Question 1

Give give two characteristics of the crust?

Answer 1

It is split into two both continental and oceanic.

beneath the oceans it is only 6-10 km thick

Question 2

Give two differences between the oceanic and continental crust?

Answer 2

The continental is older, over 1,500 million years the oceanic is less than 200 million.
The continental is heavier than oceanic.

Question 3

Give two characteristics of the mantle?

Answer 3

The mantle is made up of semi molten roc.

It is made up of lighter element such as silicon and oxygen.

Question 4

Describe the core?

Answer 4

The core is made of two layers, the outer core and inner core.
Outer core composed of liquid iron and nickel.

Question 5

The crust is separated from the mantle by the….

Answer 5

Lithosphere the Moho

Question 6

Define the lithosphere and asthenosphere?

Answer 6

The lithosphere is the rigid outer part of the earth.

The asthenosphere is the upper layer of the earths mantle.

Question 7

What are two internal sources of energy?

Answer 7

Heat from gravity.

Nuclear decay.

Question 8

What was the supercontinent called 300 million years ago?

Answer 8

Pangaea

Question 9

What was Alfred Wegeners theory?

Answer 9

Continental drift.

Question 10

What evidence supported wegeners theory?

Answer 10

The same Fossil remains of a reptile were found in both South America and Southern Africa.
The fossilised remains of a plant which existed when coal was being formed have been located only in India and Africa.

Question 11

Why did some scientist reject the theory?

Answer 11

Because there wasn’t enough evidence to prove his theory.

Question 12

What occurs at a constructive plate margin and is also know as gravitational sliding?

Answer 12

Slab push

Question 13

What occurs at a subduction zone and is the force that the sinking edge of the plate exerts on the rest of the plate?

Answer 13

Slab pull

Question 14

What is the scale that is used to measure the magnitude of volcanic activity?

Answer 14

VEI

Question 15

Describe the distribution of volcanic activity?

Answer 15

Associated with plate tetontic processes.
Located along plate margins.
Along oceanic ridges where plates are moving apart.
On or near subduction zones
Hot spots.

Question 16

Name primary effects

Answer 16

Tephra
Pyrocastic flows
Lava flows
Volcanic gases

Question 17

Name secondary effects

Answer 17

Lahars
Flooding 
Tsunamis
Acid rain
Climate change

Question 18

Outline characteristics of a primary volcanic hazard ?

Answer 18

Tephra- solid material of varying grain size ranging from volcanic bombs to ash, all ejected into the atmosphere.

Question 19

Name the characteristics of a secondary volcanic hazard?

Answer 19

Acid rain- volcanoes emit gases which include sulphur. When this combines with atmospheric moisture, acid rain results.

Question 20

What is viscosity?

Answer 20

The state of being thick, sticky and semi fluid in consistency due to internal friction.

Question 21

What 3 factors can effect viscosity?

Answer 21

The silica content
Dissolved gases
Temperature

Question 22

Name 3 types of lava and order them from the lowest to Highest viscosity?

Answer 22

Balatic
Andesitic
Rhyoltic

Question 23

Explain one way in which we can monitor active and dominant volcanoes?

Answer 23

Measure the amount of gas being produced.

Question 24

Name the case study for a volcanic eruption and when did it occur?

Answer 24

Mt Nyriagono, Congo January 2002

Question 25

give 3 pieces of background information?

Answer 25

The main crater of the volcano is 250 m deep.
Since the nineteenth century the volcano has erupted over 30 times.
The death toll reached 147

Question 26

Give two reasons why the locals are at risk?

Answer 26

It’s is a fertile region so doesn’t put people off living their encouraged large number of people to live in the area.
34 eruptions since 1882 but not all involve lava flows.