Chap 1 Gateway 2 Earthquakes and Volcanic eruptions Flashcards Preview

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Flashcards in Chap 1 Gateway 2 Earthquakes and Volcanic eruptions Deck (29)
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1

What is an earthquake?

It is a vibration in the earth's crust caused by a sudden release of energy stored in the rocks found along fault lines

2

Why does the earthquake occur?

When there is a plate movement along plate boundaries

3

What does plate movements cause?

A slow build-up of stress on the rocks found on either side of the fault

4

What happens the rocks can no longer withstand the stress in a plate movement

They suddenly slip many metres causing the the earthquake

5

What energy does earthquakes release

seismic waves

6

Seismic waves radiate out from a point of sudden energy called?

The focus

7

What is the epicentre?

It is point on the earth's surface directly above the focus

8

What follows after an earthquake event

Smaller earthquakes called aftershocks

9

What are different types of earthquakes

Deep-focus earthquakes
Shallow-focus earthquake

10

Where is the location of deep-focus earthquakes?

Between 70 and 700 km below the earth's surface

11

Where is the location of shallow-focus earthquakes?

In the upper 70 km of the earth's crust

12

What is the impact of the deep-focus earthquakes?

Smaller impact on the land as seismic waves take a longer time to reach the surface

13

What is the impact of the shallow-focus earthquakes?

Greater impact on the land as seismic waves reach land surface more quickly

14

What scale is used to measure the magnitude of earthquakes?

Richter Scale

15

What are factors aside from magnitude of earthquake to affect the extent of damage?

Population density
Level of preparedness
Distance from the epicentre
Time of occurance
Type of soil

16

Where does earthquakes occur?

At convergent, divergent and transform plate boundaries

17

Which plate boundary does earthquakes occur most and why?

Convergent, because more stress occurs builds uo when a plate subducts beneath another

18

What is the machine that records the seismic waves?

A seismograph

19

What are the risk associated with living in earthquake zones?

Tsunamis
Disruption of services
Landslides
Destruction of properties
Destruction of infrastructures
Loss of lives

20

What causes volcanic eruptions?

Tectonic activity that occurs on land and on sea

21

In regards to volcanic eruptions, how do we classify volcanoes?

Active
Dormant
Extinct

22

What are the risks of living near volcanic areas?

Massive destruction by volcanic materials
Pollution

23

What are the different types of destruction from volcanic eruptions?

Lava flows
volcanic bombs
landslides

24

What are the different types of pollution from volcanic eruptions?

Thick plumes of volcanic ash
Release of gases such as carbon dioxide, sulfur dioxide
Fine ash particles can travel afar and cause serious damage to aircraft engines

25

What are the benefits of living near volcanic areas?

Fertile soil
Precious stones and minerals
Tourism
Geothermal energy

26

What the types of crops that the fertile soil of Bali and Java support

Tea
coffee
rice

27

What are the types of precious stones that volcanic rocks contain?

Diamonds

28

What is an example of tourism that a volcanic area provides?

Pompei

29

How is Geothermal energy derived?

From the heat in the earth's crust. When groundwater comes into contact with the hot rocks, it heats up as hot water and steam. The steam can be harnessed to drive turbines and produce electricity.