Hazards - types/factors/tectonic theory

Question 1

Define Natural Hazards

Answer 1

A natural event that threatens people and property that has the potential to cause damage, destruction and deaths.

Question 2

Define the different types of Natural hazards

Answer 2

• Chronic hazard - a hazard that;s long-term and persistent (ongoing) such as global warming and El Niño.
• Meterological Hazard (Atmospheric) - hazards causes by weather and climate such as tropical storms and droughts.
• Geological Hazard (Tectonic) - hazards caused by the movement of tectonic plates such as earthquake and volcanoes.

Question 3

Natural Hazards - Risk of disaster

How much is the risk of the disaster is of the natural hazards is based on the knowledge of potential ——————- and Chronic ——- event which include:
- Past reccurance intervals
- magnitude
- duration

Name three more.

Answer 3

How much is the risk of the disaster is of the natural hazards is based on the knowledge of potential catastrophic and Chronic physical event.

• Future probability
• speed of onset
• spatial extent

Question 4

Vulnerable system - Risk of disaster

The risk of diasaster is based on the exposure, sensititivy, and resilience of:
- population
- economy
- natural resources
Name three more.

Answer 4

• land use and development
• infrastructure and critical facilities
• cultural assests (as some believe is the game of God to test us)

Question 5

Vulnerable system - Risk of disaster

The risk of disaster is based on the ability, resources and willingness to:
- mitigate
- prepare
Name two more

Answer 5

• respond
• recover

Question 6

Define hazard risk

Answer 6

the probability that a natural hazard occurs

Question 7

Factors affecting hazard risk

Vulnerability

What affects vulnerability?

Answer 7

• The higher the population of an area (which is exposed to the natural hazard) the greater the probability they will be affected.
• Also tells how susceptible the area is to the impacts of the hazard depending on its wealth, infrastructure, technology and population.
• Population, wealth and technology, eduction, age , urban and rural

Question 8

Factors affecting hazard risk

Capacity to cope

Answer 8

The better prepared the country is for a natural hazard, the lower the threat and less damage they face. The HICs are better prepared for coastal flooding events.

Question 9

Factors affecting hazard risk

Nature of natural hazards

Answer 9

The hazard risk of some hazards are greater than others. This is dependent on:
* whether the hazard can be predicted
* the frequency in which it occurs
* the magnitude of the hazard

Question 10

Tectonic Theory

1) Who came up with the tectonic theory?
2) What name did they give to the single continent?
3) What did this person believe that caused the drifiting?
4) Who else supported this theory?
5) What did they say and how did they back it up?

Answer 10

• The theory was developed by Alfred Wegener in the early 20th century, who noticed that all the continents fit together like a jigsaw and stated that at once it was a one single ‘supercontinent’; the Pangaea.
• He believed that the continents started to drift apart 300 million years ago and it was due to the spin of the earth that caused the drifting away.
• Arther Holmes supported this theory and also stated that the plates moved apart because of the convection current in the earth’s mantle; he said as the substance is heated, it decreases the density which rises until it cools and sinks again.

Question 11

Tectonic theory

What evidence is there for the tectonic theory?

Answer 11

• Study of fossils: similar fossils are found on different continents, suggesting that once they were close or joined together.
• Shape of continents: they fit together like a jigsaw
• Pattern of rocks: similar pattern ofrocks layers are found on different continents, suggesting that the regions were once close or joined.

Question 12

Layers of Earth

1) Name the four layers of the Earth.
2) How thick is the crust?
3) What is the outer core made of?
4) Give 2 reasons of high temperature of the inner core?
5) What is magma?

Answer 12

• Crust:
  6-70km thick; broken in plates; oceanic and continental plate.
• Mantle:
  sem-molten rock called magma; has temperture around 1300-5000 degrees celcius.
• Outer core:
  a liquid layer made mainly from iron and nickel
• Inner core:
  a solid layer made from iron and nickel; temperature is almost to 5,500 degrees celcius due to high pressure and radioactive decay.

Question 13

Compare oceanic plate and continental plate

Answer 13

Oceanic plate is thin, new, dense and found under sea.

Continental plate is thick, less dense, older and is overland.