Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Geography- Hazards > Seismic Hazards > Flashcards

Seismic Hazards Flashcards

You may prefer our related Brainscape-certified flashcards:
U.S. Geography flashcards World Geography flashcards
1
Q

Seismicity

A

Earth shaking

Can be human induced through fracking, mining and reservoir construction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Earthquake Formation

A

Friction along margins = stress in lithosphere
Stress suddenly overcome
Plates fracture along faults
Sends a series of shock waves to the surface
Tremors can be followed be several weeks of after shocks whilst crust settles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What factors make the damage done by an earthquake worse?

A 
Time of day
Depth of focus
Population density 
Level of development 
Building quality
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

P Waves

A

Fast moving, first to reach the surface
Travel through solids and liquids (crust, mantle, core)
High frequency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

S Waves

A

Second waves to reach the surface
Travel through liquids (mantle)
Sideways movement, shaking earth at 90° to direction of travel
Do more damage than P waves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Love Waves

A

Slowest moving

Do most damage because of sideways movement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Rayleigh Waves

A

Radiate from epicentre in complicated, low frequency rolling motions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Tsunami

A

Large sea wave generated by earthquakes on the ocean floor, large landslides and submarine volcanic eruptions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Tsunami Formation

A

Pressure between 2 plates suddenly released
Large waves of energy displace water
Water train created, spreads in concentric circles to shore
Upon reaching shore, wave shoaling occurs (friction = highly destructive wave)
Wave retreats taking debris, forming the next wave

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What factors make the damage done by a tsunami worse?

A 
Distance travelled
Focus depth (shallower = larger)
Population density 
Level of development 
Warning given
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Landslide

A

Movement of rock, debris or earth down a slope

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Landslide Formation

A

Ground shaking due to earthquake destablishes cliffs and steep slopes
Causes material to quickly move down slope

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What factors make landslides worse?

A

Steep gradient
High relief rainfall (saturates ground = unstable)
Shallow soil
Unstable rock

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Liquefaction

A

Jelly like state of silts and clays resulting from intense ground shaking

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Liquefaction Formation

A

Sand or soil mixes with ground water

Becomes very soft, causing subsidence and building collapse

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What factors make liquefaction worse?

A

High ground water
Reclaimed soil
Sandy soil (loosely packed grain = more pore spaces to fill with water)

17
Q

Richter Scale

A

Logarithmic
1 to 10+
Easy comparison between disasters
Quantitative

18
Q

Modified Mercalli Scale

A

Qualitative
0 to XII
Different levels for different areas
Only useful with buildings around

19
Q

Preparedness: Name some of the events that occur in the minutes before an earthquake

A

Microquakes before main tremor
Magnetic changes in local rock
Unusual animal behaviour

20
Q

Prevention: Although almost impossible to prevent, what have some scientists suggested?

A

Putting water and oil in margins
Lubricates movement
Plates will slide not stick

21
Q

Adaptation: What form does protection mainly take?

A

Preparation by modifying the human and built environments to decrease vulnerability and reduce loss

22
Q

Adaptation: 2 features of hazard resistant structures

A

Concrete weight on roof- moves in opposite direction to force of earthquake, counteracting stress
Rubber shock absorbers in foundations- allows some movement

23
Q

Adaptation: What can people in old buildings do?

A

Retrofit them to make them more aseismic

24
Q

Mitigation: How does education help?

A

Minimises loss of life, through earthquake drills

25
Q

Adaptation: 2 ways fires can be prevented

A

Smart meters- cut off gas in an earthquake over a certain magnitude
Tokyo gas companies- switch off pipelines, reducing the number of fires

26
Q

Adaptation: 2 ways of protecting against tsunamis

A

Tsunami warning systems

Build 12m high tsunami walls (ineffective)

27
Q

Protection: How can the emergency services be ready?

A

Heavy lifting gear available
Carefully organised and planned response
People in communities given first aid training to treat injured before help arrives

28
Q

Mitigation: Why are people urged to take out insurance in richer countries?

A

To cover their losses- expensive

29
Q

Adaptation: Land use planning

A

Schools and hospitals built in low risk areas

Green space put into high risk areas, forming a safe area away from fires and aftershock debris + distribution areas

30
Q

Prevention: How can any impacts from liquefaction be prevented?

A

Authorities preventing building on land prone to liquefaction

31
Q

Mitigation: How to earthquake and tsunami warning systems reduce damage caused?

A

Detect weak shockwaves
TV / SMS warnings given
Aids evacuation

Geography- Hazards (13 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions