seismic hazards Flashcards

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1
Q

wht are the 5 ways you can predict seisimic hazards

A

-animal behaviour
-radon gas
-water level
-foreshocks
-seisometers

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2
Q

animal behaviour

A

animals have certain sensory perception that is denied to humans, the stanford research institute have a project called project earthquake watch in which 70 species of animals are studied to look for changes in behaviour.

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3
Q

advantages of using animal behaviour

A

-cheap
-animals can show signs up to several days before the earthquake
-high responses near epicentral regions

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4
Q

disadvantages of using animal behaviour

A

-time consuming
usually only show signs in very high category earthquakes

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5
Q

water level

A

changes in water level can indicate an earthquake, the rise and lowering of water is measured in deep wells 410-670 metres. around 3-10 days beforehand the water level will begin to change

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6
Q

advantages of using water level

A

-easy to measure
-large amount of time to allow people to evacuate

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7
Q

disadvantages of using water level

A

-only happens in certain regions

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8
Q

radon gas

A

radon gas is a radioactive has released prior to an earthquake, stations can measure radon levels up to hundreds of kilometres from the epicentre

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9
Q

advantages of using radon gas

A

-can be measured very far away from the epicentre
-can be measured days before the event

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10
Q

disadvantages of using radon gas

A

–equipment used to measure gas is very expensive
-can cause radiation sickness in some cases

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11
Q

what is the epicentre

A

the first point affected on land

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12
Q

what is the focus

A

the point inside the crust where pressure is released

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13
Q

how do seisometers work

A

Seismometers allow us to detect and measure earthquakes by converting vibrations due to seismic waves into electrical signals,

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14
Q

what is a wave

A

a vibration that transfers energy from one place to another

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15
Q

what is a p-wave

A

the first wave to arrive from an earthquake,they are the fastest and travel in longitudinal direction

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16
Q

what is an s-wave

A

a transverse wave that arrives second after a p-wave.

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17
Q

what is a love wave

A

a seismic wave that occurs at the surface

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18
Q

what is the first wave to arrive from an earthquake

A

a p-wave

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19
Q

what is the second wave to arrive froman earthquake

A

an s-wave

20
Q

what wave occurs on the surface

A

a love wave

21
Q

what is the point inside the crust where pressure is released

A

the focus

22
Q

what scales measures the size of an earthquake

A

the richter scale, the mercalli scale and moment magnitude scale

23
Q

what is the richter scale

A

a numerical scale for expressing the magnitude of an earthquake on the basis of seismograph oscillations.

24
Q

what does the richter scale go up to

A

9

25
Q

how do the numbers on a richter scale work

A

each number increases magnitude by 10x

26
Q

what is the mercalli scale

A

a scale that measures how much damage is caused by the earthquake based on observations

27
Q

what is the measurements on the mercalli scale

A

i to xii

28
Q

what is the moment magnitude scale

A

a scale that measures the total moment release of the earthquake

29
Q

what factors affect how much a place is impacted by an earthquake

A

-population density
-distance from epicenter
-time of day
-magnitude of earthquake
-ability to response
-income

30
Q

how does the time of day have different impacts on a place

A

during the day people are more aware and will have more time to react,so the impacts will be lessened during the day.

31
Q

how does the distance from epicentre have different impacts on a place

A

the shaking is greatest near the epicentre, so areas in closest proximity will experience the greatest damage

32
Q

what is soil liquefaction

A

where saturated soil is shaken, creating damaging mudflows

33
Q

where saturated soil is shaken, creating damaging mudflows

A

soil liquefaction

34
Q

what are the primary impacts of an earthquake

A

-ground shaking (shockwaves travel from epicentre)
-ground rupture
-collapsing buildings
-death

35
Q

what are secondary impacts of an earthquake

A

-landslides
-soil liquefaction
-tsunamis
-contaminated water
-unemployment

36
Q

how does a tsunami form due to an earthquake

A

The sudden vertical displacements over such large areas, disturb the ocean’s surface, displace water, and generate destructive tsunami waves

37
Q

what can ground shaking lead to

A

-damaged roads which will restrict access
-landslides
-collapsing of buildings

38
Q

example of an LIC earthquake

A

Haiti earthquake

39
Q

what year did the haiti earthquake take place

A

2010

40
Q

where is haiti

A

Haiti is located in the Caribbean about 700 miles away from Miami, Florida

41
Q

how many people were effected by the haiti earthquake

A

3.5 million

42
Q

how many people were estimated to have died in the haiti earthquake

A

230,000

43
Q

how many schools were destroyed in the haiti earthquake

A

400

44
Q

how much was the cost of recovery in haiti

A

11.5 billion

45
Q

what was the total cost of the earthquake in haiti

A

8 billion, 120% of haitis economy

46
Q

what were the secondary impacts of the haiti earthquake

A

-diseases spread around camps due to deterioration of sanitation
-port was damaged so aid could not be transported there
-50,000 people ended up in camps, crime in these camps was severe

47
Q

what are the primary impacts of the haiti earthquake

A

230,000 deaths
Over 1 million left homeless