Tectonics Flashcards

1
Q

Pangea

A

All of the continents were previously connected as one super continent

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2
Q

How are fossils evidence of the theory of plate tectonics?

A

Fossils of the freshwater mesosaurus are found in both south Africa and south America

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3
Q

How is coal evidence of the theory of plate tectonics?

A

Coal can be found in antarctica, it couldn’t have formed there at its current latitude, it needs tropical conditions.

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4
Q

How are maps evidence of the theory of plate tectonics?

A

Maps of the ocean floor show the 11km marianas trench in the phillipines.

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5
Q

Who created the continental drift theory and what is it?

A

1) Alfred Wegner
2)Continents move around the earth like rafts

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6
Q

Where are earthquakes and volcanic activity?

A

Plate boundaries

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7
Q

Why do tectonic plates move?

A

Convection currents from earth’s core

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8
Q

Convection currents definition

A

Hot liquid magma currents that move in circles in the asthenosphere causing plates to move

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9
Q

Seafloor spreading definition

A

Mid ocean ridges/underwater mountains form when hot magma is forced up from the asthenosphere. New crust created splits plates

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10
Q

Subduction definition

A

As new crust is created in one place its destroyed in another. As 2 oceanic plates move to eachother one slides under the other into the mantle.

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11
Q

Convergent plate boundaries + example

A

The denser oceanic plate subducts under the other plate. The oceanic plate melts in the Benioff zone. Magma forces itself up to the surface. Eg Mt St Helens Washington state USA.

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12
Q

Divergent plate boundaries + example

A

Rift volcanoes. Less explosive. Non viscous lava. Basaltic lava. Eg mid Atlantic ridge.

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13
Q

Describe Mt Kilauea Hawaii.

A

-Hawaii islands created by pacific plate moving NW over hot mantle plane.
-High heat + low pressure at the base of lithosphere melts the rock
-Magma rises through fissures forming volcanos.
-Plate moves over hotspot. Existing active volcanos moved from hotspot
-New volcanos formed
-Old volcanos cool and subside

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14
Q

Effusive volcanos

A

High temp, low viscosity, high dissolved gas content, divergent margins, low silica, narrow base

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15
Q

Explosive volcanos

A

Low temp, high viscosity, low dissolved gas content, subduction zone, high silica, wide base

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16
Q

Paleomagnetism

A

Result of the zone of magma striking the Earth’s magnetic polarity when it cools. Used to determine historic periods of tectonic activity by remaking plate boundaries.

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17
Q

Hypocentre

A

The point within the Earth where an Earthquake rupture starts

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18
Q

Liquefaction

A

Where water saturated material temporarily loses normal strength and behaves like a liquid due to the pressure of strong shaking. Occurs in saturated soils.

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19
Q

Primary waves

A

-Type of body waves
-Compression wave/longitudinal
-Moves through solid/liquid/gas

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20
Q

Secondary waves

A

-Type of body waves
-Transverse/ move up and down/side to side
-Sheering waves

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21
Q

Love wave

A

-Type of surface wave
-Moves side to side
-High amplitude

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22
Q

Rayleigh wave

A

-Type of surface wave
-Move in an elliptical motion
-Further reach
-

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23
Q

Surface waves

A

slower
large
more destructive

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24
Q

Why are Earthquakes dangerous?

A

Soil liquefaction
buildings collapsing
landslides
tsunamis

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25
Q

How do buildings collapse

A

S and L waves shake the ground violently and can cause buildings to collapse especially if weak foundations

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26
Q

How do tsunamis happen?

A

-An Earthquake, volcanic eruption or landslide happens underwater
-Water is displaced. Rises due to tectonic energy
-Gravity pulls the water down as a wave

(One side of crack goes up forcing water above that piece with in)

Water is dragged to back to sea first (drawback)

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27
Q

Human factors( Tsunamis)

A

-Power infrastructure
-Population
-Education/preparation
-Warning system
-Coastal development
-urban/rural

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28
Q

Physical factors(Tsunamis)

A

-Magnitude of earthquake/size of landslide
-Distance from epicentre
-Coastal inlet- higher wave
-Relief (flat land is worse, easier for wave)
-Timing
-Gradient of shore
-Ecosystem
-Amplitude, water column displacement,

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29
Q

Example of a tsunami:

A

Asian tsunami 2004 was caused by destructive plate boundary east of thai coastline

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30
Q
A
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31
Q

Hazard definition

A

A perceived natural event that has the potential to threaten both life an property

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32
Q

Disaster definition

A

The realisation of a hazard that causes significant impact on a vulnerable population. Over 100 affected

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33
Q

What makes a population vulnerable (Deggs disaster model)

A

Poor infrastructure
Clean water
Healthcare
Education
Warning systems
Politics
Population density

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34
Q

Root causes (pressure and release model)

A

Limited access to power, structures, resources

Political/economic systems

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35
Q

Dynamic pressures (Pressure and release model)

A

Lack of training/investment/press freedom

Rapid population change
Rapid urbanisation
Deforestation

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36
Q

Moment magnitude scale

A

Measure of the energy released by an earthquake based on the “seismic moment” of an earthquake on a logarithmic scale

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37
Q

Richter scale

A

A measurement of the height of waves produced by earthquakes on a logarithmic scale

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38
Q

Mercalli scale

A

A measurement of the impacts of an earthquake based on people’s experiences

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39
Q

Volcanic explosivity index

A

A measurement of the volume of material ejected from a volcano, height of cloud and other observations. Logarithmic scale

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40
Q

Limitations of hazard event profiles

A

Don’t show human factors like capacity to cope

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41
Q

Limitation of mercalli scale

A

Can be generalised or exaggerated

42
Q

Limitation of richer scale

A

Doesn’t look at duration/physical environment/context

43
Q

Resilience definition

A

The ability of a community/government/society to prepare for, deal with and recover from hazard

44
Q

Risks in San Francisco

A

-San Andreas fault
-dense population
-Flat land - - > liquefaction
-Tsunami risk

45
Q

San fransicso resilience

A

-Quake proof buildings
-Higher income–> repair costs
-Response plans
-Education / training
-Stable gob

46
Q

Haiti port au Prince risk

A

-Make shift slums not reinforced
-Steep land so buildings will collapse
-No preparation / education
-Unstable corrupt gov
-2/3 below poverty line

47
Q

2015 Nepal earthquake impacts

A

-9000 killed
-800000 houses destroyed
-$8 billion damages
-Loss of tourism
-500000 homeless

48
Q

2010 Chile earthquake impacts

A

-214 killed
-Electric/water/phone lined cut
-Flights diverted
-Infrastructure damaged

49
Q

Haiti 2010 earthquake impacts

A

-7 magnitude
-220 000 killed
-Poorest in W hemisphere
-Cholera outbreak 216000 caught it
-360000+ injured

50
Q

Nyiragongo eruption tectonic setting

A

-Most destructive effusive eruption
-Steep sloped volcano
- layers of hardened lava, ash and rocks
-Congo–> Goma
-lava lake in summit
-faults and plates stretched as they move apart
-Divergent boundary nubian and somali plate
-low viscosity basaltic lava
37kmh lava flows

51
Q

Nyiragongo social impacts

A

125000 homes destroyed by lava
200+ killed by c02 poisoning + lava
40000 evacuated
Hygenine problems+water shortage
Looting in Goma
120000 homeless
Cholera

52
Q

Nyiragongo economic impacts

A

80% of AIRPORT airstrips covered in lava
Business + shops destroyed

53
Q

Nyiragongo environmental impacts

A

Crops and livestock destroyed by laba

Volcanic gases caused acid rain damaging land

54
Q

Nyiragongo short time management

A

-Regugee camps set up
-Oxfam 33 tonnes water + cleansing equipment
-$35 million aid
-shelters made from scrap metal
Emergency vaccines WHO
UN 260 tonnes food a week

55
Q

Long term management nyiragongo

A

-Officials retrained with evacuation plans and communities to target
-evacuation drills
Leaflets info
Lava lake monitored

56
Q

Hazard event profile factors

A

Magnitude
Speed of onset
Duration
Areal extenr
Spatial predictability
Frequency

57
Q

Physical factors of 2004 Indian ocean tsunami

A

Low lying coastlines
Epicentre close to communities
Large tsunami

58
Q

Human factors of 2004 Indian ocean tsunami

A

Densely populated coastlines
Mangrove forests cut down so less natural protection
LICs didn’t have resources for protection

59
Q

Social impacts of 2004 Indian ocean tsunami

A

120 000 Thai workers lost jobs
60% of Sri Lankan industrial infrastructure gone
70% of some villages killed
1500 villages in sumatra destroyed

60
Q

Economic impacts of 2004 Indian ocean tsunami

A

Us10 billion dollars
Thai tourism lost 25 million in a month
Fishing tourism farming industries
Jetties washes away

61
Q

Environmental impacts of 2004 Indian ocean tsunami

A

Vegetation and top soil remobed
Agricultural soil contaminated
Ecosystems like wetlands damaged
Freshwater supplies contaminated

62
Q

Management of 2004 Indian ocean tsunami

A

Warning systems electronic sensors
Education
Disasters emergency comitee spent over 40 million dollars in Sri Lanka and indonesia
Evacuation shelters

63
Q

Social impacts of 2011 Japan tsunami

A

-6000 injured
-16000 killed
-50000 missing
-46000 buildings destroyed
-300 hospitals damaged
-fukushima nuclear meltdown

64
Q

Economic impacts of Japan 2011 tsunami

A

Airports famaged
Fukushima
Railways damaged
360 billion dollars

65
Q

Environmental impacts of 2011 Japan tsunami

A

Ecosystems
Groundwater contamination
Gases stored in insulation released

66
Q

Cause of Japan 2011

A

Eurasian, pacific and phillipine plates
7.2 on richter scale
Pacific plate went under
Eurasian plate lifted 9m
Epicentre underwater causing tsunami
Water 500mph

67
Q

Why aren’t all statistics trustworthy?

A

Deaths may be from hazard itself or secondary effects or long term effects
Remote locations aren’t recorded eg myanmar in 2004
False claims to get more money
Thsiland downplayed consequence to protect tourism

68
Q

Drought in the Philippines

A

Can happen when wet season hasn’t brought enough rain to last dry szn. Decreased HEP

69
Q

Volcanic activity in the Philippines

A

Eg mt pinatubo 800 killed $700 million
25 volcanoes in the country
Deforestation reduced interception

70
Q

Flooding in the phillipines

A

Happens after typhoons
Happens after tdunamks
Damage to properrt
2010 450 000 displaced

71
Q

Governance definition

A

The process by which a country is run

72
Q

Example country with good governance

A

Iceland

73
Q

How did Iceland demonstrate good governance after te eyja volcano in 2011

A

700 locals evacuated
Seismic proof infrastructure
Planned evacuation routes
Gov promoted tourism
Education + informed population

74
Q

Example country of bad governance

A

Haiti

75
Q

How does Haiti demonstrate bad governance

A

Corruption and political volatility
Weak government
25 % in extreme poverty
Relies on other countries for help
Military take over

76
Q

Mitigation definition

A

Strategies to avoid, delay or predict hazard events through preparing for the hazard

77
Q

Economic governance

A

Decision making that impacts economic activities like jobs business trade. Impaxts equity poverty and quality of life

78
Q

Political governance

A

Decision making to create policies eg planning and reduction of natural disasters

79
Q

Administrative governance

A

System of policy implementation and needs good national and local governance. Functioning enforcement. Vulnerability monitoring. Safety standards

80
Q

Multi hazard zone example

A

Philippines

81
Q

What can be monitored for volcano prediction?

A

Earthquakes, ground movement, water chemistry, rock chemistry, volcanic gas

82
Q

How can you modify the loss of a disaster?

A

-Give aid to poor people/countries
-Give insurance to reach people/countries

83
Q

How can you modify vulnerability in a disaster?

A

-prediction/warning eg Indian ocean warning system
-preparedness
-Education
-Land use planning

84
Q

How can you modify the event? (earthquakes)

A

Can’t control Seismic activity to focus is on making earthquake proof buildings and retrofitting existing ones. Eg San Francisco

85
Q

How can you modify the event? (Volcanoes)

A

Lava can be diverted or chilled with water. Eg Heimay

86
Q

How can you modify the event? (Tsunamis)

A

Coastal defences like sea walls and mangroves.
Limited evidence on effectiveness

87
Q

Modify cause of event

A

Only possible for small scale hazards. Environmental control

88
Q

What were the problems with the aid response in Haiti?

A

-Public institutions sidelined by well meaning organisations that rushed in
-90% of funding went to non Haitan organisations
-International donors didn’t want to give money directly to Haitan organisations
-Little access to sanitation health education

89
Q

Parts of the hazard management cycle

A

Prevention and mitigation
Preparation
Response
Recovery

90
Q

Parts of the hazard management cycle

A

Prevention and mitigation
Preparation
Response
Recovery

91
Q

Key players

A

Local people, architects, local gov, insurers, national gov, NGOs, Educators, IGOs, Scientists, Constructors

92
Q

What do local people do as key players

A

Being prepared and following advice. They didn’t do this in Nyiragongo

93
Q

What do architects do as key players

A

Design earthquake proof buildings

94
Q

What do local government do as key players?

A

Try to enforce building restrictions eg in vesuvius Italy

95
Q

How are insurers key players

A

Paying out those with insurance eg after Japanese tsunami

96
Q

How are national government key players

A

Co ordinating response
Land use zoning

97
Q

How are NGOs key players

A

Help/hinder with response eg in Haiti they hindered

98
Q

How are educators key players

A

They teach what to do in a earthquake eg GreatShakeout

99
Q

How are IGOs key players

A

Bringing countries together to learn from mega disasters

100
Q

How are scientists key players

A

Predicting eruption. Tracking ask cloud eg Eyja Iceland

101
Q

Scientists as key players L’aquila example

A

-6.3mag 300 killed, Italy
-6 scientists + ex gov official arrested
-guilty of manslaughter due to failing to predict earthquake
-later released.
This shows misunderstanding of earthquake science which led to their conviction