Geography

Question 1

What is the Greenhouse Effect?

Answer 1

Greenhouse effect is a natural process by which the world keeps warm enough to be inhabitable. The different gas layers that cover the Earth keep a balance in the atmosphere which allows for life to thrive.

Question 2

List 3 Greenhouse gasses.

Answer 2

• Carbon dioxide (CO2)
• Methane (CH4)
• Chloroflourocarbons (CFC’s)
• Nitrous Oxide
• Flourinated Gasses

Question 3

What is the ozone layer?

Answer 3

The fine ozone layer which is only about 3 millimetres thin is situated in the atmosphere at a height of between 20 and 30 kilometres. This layer absorbs most of the ultraviolet rays of the sun which are very harmful to our health.

Question 4

How did climate change effect the ozone layer?

Answer 4

● This layer was slowly deteriorated through the use of CFC’s
● Due to this the risk of skin and eye diseases increased.
● We call the deteriorated area the Ozone Hole.

Question 5

The way forward to heal the ozone layer.

Answer 5

● In 1987 all countries banned CFC’s
● Thanks to this the damage to the ozone layer will repair itself in around 50 years.

Question 6

How did the increase in Global temperatures affect the
* Tourism Industry and Economy
* Biodiversity and Loss of Species

Answer 6

• Tourism Industry and Economy:
  1. Mountains with ice will melt and this stops tourism in those areas.
  2. Sea level is rising due to ice melt and this will force people living in low lying islands to leave.
• Biodiversity and Loss of Species
  1. A lot of species will end up becoming extinct due to losing their habitat and food
  sources.
  2. Ice is melting resulting in a sea level rise of 1-2 mm per year.

Question 7

How did the increase in Global temperatures affect Malta?

Answer 7

Agriculture :
* More droughts and lack of water resulting in a lot of plants dying.
* More farmers having to quit their jobs due to high expenses.
* Lack of water and food resources resulting in more livestock dying.

Lack of water and long periods of Drought
* Lack of water means more dependence on desalination plants resulting in more money that has to be used.

Question 8

Name the 3 main sources of energy.

Answer 8

• Petroleum (oil)
• Natural gas
• Coal

All of these are fossil fuels

Question 9

From where do fossil fuels come from?

Answer 9

● All these energy sources come from the remains of plants and creatures which lived hundreds of millions of years ago. Oil and gas were formed more than 300 million years ago from microscopic organisms which lived in seawater.
● On the other hand the remains of trees and plants which lived on land brought about the formation of many layers of coal. These sources of energy are non-renewable since their reserves are being used much faster than they are
being formed.

Question 10

Name a few negative impacts of coal, oil and gas.

Answer 10

● These cause the emission of large quantities of smoke with greenhouse gases and other substances which pollute the air and cause climate change and acid rain.
● The toxic smoke emitted from the chimneys of power stations damages natural ecosystems and is harmful to our health.
● Electrical generation by means of coal fired power stations causes air pollution by means of carbon dioxide CO2, (which leads to climate change), and sulphur dioxide SO2, (which is the main agent of acid rain).
● Coal is heavy and bulky to transport and the ash which is left over must be dumped somewhere.
● During the whole process of oil production involving drilling, extraction and transportation, serious accidents may happen, which cause pollution of the air, land or sea.
● Sometimes large amounts of oil were spilled on land or sea while it was being transported from one country to another by huge pipes or tankers. Such accidents cause a deep and negative impact on the environment for a number of years.
● Moreover the price of oil and gas varies greatly in international markets since it is affected by the current economic, political and military conditions.

Question 11

Name the positive impacts of coal, oil and gas.

Answer 11

• As a means of electriacal generation, oil and gas are more effiecient than coal. More importantly they are easier to transport from one place to another by means of pipes and large tankers.
  ● These Fossil Fuels are cheaper when compared to other energy sources, but they pollute the environment around us.

Question 12

How does nuclear energy work?

Answer 12

● Nuclear power is created by the splitting up uranium atoms in nuclear reactors.
● By this process, called fission, a great energy is formed to heat water, turning it into steam.
● This steam turns the turbine which then produces electricity. Uranium is a non-renewable metal. However, since it can be found in large quantities, its reserves can serve us for many years to come.

Question 13

What happens to Uranium?

Answer 13

● The re-use of nuclear waste is also possible. This keeps our mind at rest that the reserves of this metal will serve for a long time.
● After its extraction from underground, uranium is shaped into rods according to the specifications needed by the nuclear reactor. One rod can serve for six years thus reducing the costs of transporting this metal.

Question 14

A benefit of Nuclear Energy

Answer 14

● While electricity is generated in a nuclear power station no pollutants are emitted.

Question 15

Disadvantages of Nuclear Energy.

Answer 15

• The fear of exploding these implants and the deadly radioactivity.
• One other problem is the disposal of used uranium rods. These are very dangerous since they remain radioactive for thousands of years.

Question 16

What are the 4 types of renewable energy?

Answer 16

• Solar Energy
• Wind Energy
• Hydroelectric Energy
• Geothermal Energy

Question 17

The outer crust of the world can be divided into 2 types:

Answer 17

• Continental Crust
• Oceanic Crust

Question 18

What divides the earth’s crust into tectonic plates?

Answer 18

The great heat from the earth’s core reaches the mantle, causing convectional currents in the magma. These circular currents divide the earth’s crust into large parts called tectonic plates.

Question 19

What are plate margins?

Answer 19

The plate margins are the places where most volcanoes are situated and where most earthquakes occur.

Question 20

In how many types of plate margins are there?

Answer 20

4 types

Question 21

What is a destructive margin?

Answer 21

When two plates move towards each other a destructive margin is formed and one of them is subducted and destroyed under the other. Earthquakes and destructive
volcanoes are very common in these margins.

Question 22

What is the collision margin?

Answer 22

When two plates move and push towards each other, the world’s crust may also bend and be crushed under the resultant great pressure. In such collision margins mountain ranges such as the Alps in Europe and the Himalayas in Asia are formed.

Question 23

What are constructive margins?

Answer 23

In other places the plate margins are moving away from each other. These are called constructive margins and are mostly found under the oceans. The empty space which is formed is taken by magma and lava. When these cool and solidify they build a narrow stretch of high land or ridge all along the plate margin.

Question 24

What is the conservative margin?

Answer 24

In conservative margins the tectonic plates are moving past each other. This type of movement causes strong earthquakes.

Question 25

A volcano is said to be ________ if it shows no sign of activity in two or three thousand years.

Answer 25

A volcano is said to be extinct if it shows no sign of activity in two or three thousand years.

Question 26

By the ________ ________ we would know the strength of the tremor and the seismic waves which travel underground during an earthquake. These tremors are measured by an instrument called ____________. This draws a seismic trace of the earthquake called ____________. The Richter scale measures from grade ____________. Generally an earthquake which marks grade 7 to 10 on the Richter scale will cause considerable damage.

Answer 26

By the Richter scale we would know the strength of the tremor and the seismic waves which travel underground during an earthquake. These tremors are measured by an instrument called seismograph. This draws a seismic trace of the earthquake called seismogram. The Richter scale measures from grade 1 to 10. Generally an earthquake which marks grade 7 to 10 on the Richter scale will cause considerable damage.

Question 27

Important terms of earthquakes:

Answer 27

Focus: This is generally 5 to 15 kilometres below the surface.

The epicentre: is the place where the earthquake reaches the surface, where it is most strongly felt and where most damage is done.

**Seismic waves: **are emanated from the focus in all directions and are measured by a seismograph which traces a seismogram. The further the seismic waves travel from the epicentre, the weaker the tremor will be and the lower the damage.