Tectonic Hazards

what is an intra plate earthquake?

don't happen at plate boundaries linked with hotspot theory and fault lines

% of earthquakes that occur at a plate boundary

95% of earthquakes

% of volcanoes around the ring of fire

75% of volcanoes

what ocean does the ring of fire surround

the pacific ocean

what is a convergent plate boundary also known as?

known as a destructive plate boundary

% of tsunamis that occur in the Pacific ocean?

70% of tsunamis

what is a transform boundary also known as?

known as a conservative boundary

what is a divergent plate boundary also known as?

known as a constructive plate boundary

why are intraplate earthquakes not fully understood?

plates moving over a spherical surface causes weak spots and stresses on plates can cause old faultlines to reactivate

what are examples of intraplate eathquakes?

2011 Mineral, Virginia and 1812 New Madrid

where do hotspot volcanoes occur?

over magma plumes in the asthenosphere eg Hawaii and Iceland

properties of an oceanic plate?

thinner and denser than continental mainly made of basalt

how thick is an oceanic plate?

6-10km

how thick is a continential plate?

45-50km

properties of a continental plate?

thicker, less dense, mainly made of granite

what is mantle convection?

Mantle convection is the slow creeping motion of Earth's solid silicate mantle caused by convection currents carrying heat from the interior of the Earth to the surface.

how is the sea floor spreading theory supported

Palaeomagnetism provides evidence

what is Palaeomagnetism?

the study of the Earth's magnetic field shown in the magnetic orientation in rocks

what is the benioff zone?

The narrow area where earthquakes tend to occur in the subduction is known as?

example of a constructive plate boundary?

Mid-Atlantic Ridge is an example of?

what are long, narrow depressions in the ocean floor with depths of over 6km and up to 11km

Deep sea trenches

example of a deep sea trench

Marina trench

what plates formed the Himalayas?

Eurasian and Indian plates

Example of a collision plate boundary?

Himalayas

what margin do strike slip faults occur?

along conservative / transform plate boundaries

example of a transform boundary

The San Andreas Fault is an example of what?

characteristics of P waves

Body wave, Fastest, Reach the surface first, Travel through liquids and solids, Cause backwards and forwards shaking, Least damaging

characteristics of S waves

Body wave, Slower than P waves, Only travel through solids, Cause a sideways motion, More damaging

Characteristics of Love waves

Surface wave, Slowest, Cause a side to side motion, Larger and energy is focussed on the surface, Most damaging

primary hazards in an earthquake

Ground shaking & crustal fracturing

what is crustal fracturing?

when the movement causes the Earth's crust to crack

secondary hazards in earthquakes

landslides and avalanches, Liquefaction and flooding

primary hazards in an eruption

Pyroclastic flow, Lava flow, Ash falls, Gas eruptions

Secondary hazards of an eruption

Lahars, Jökulhlaups

what is a Jökulhlaups

name of floods caused by a sudden release of water and rocks when glacial ice is melted by the eruption

Heights of tsunamis

they frequently reach 5-10 meters, but can reach 30 meters

what happens to the shore when the tsunami wave reaches it?

when is a vacuum is created and the water recedes rapidly out to sea leaving the sea bed exposed?

Causes of tsunamis

earthquake, landslides, underwater eruption, (rarely) meteor strike

what is a basic definition of a hazard

event which has the potential to cause harm to the environment, people or the economy

what is a basic definition of a disaster

harm actually occurs to the environment, people or the economy, Deggs model where hazard intersects with people

What is the hazard risk equation?

(Hazard x Vulnerability) // capacity to cope

what is vulnerability in a narutal hazard?

how susceptible an area or population is to damage from a particular hazard event

what effects vulnerability?

Level of development, Population density, Size of hazard, Preparation and planning

what is a basic definition of resilience of a natural hazard?

capacity to withstand or recover quickly from an event

Factors affecting resilience

Bulding construction (are they up to code or were corners cut?), Population density, level of urbanisation, corruption, education, emergancy services and infrastructure, wealth and healthcare

Main sectors in the Pressure model of the PAR model

Root causes - (resources, decision making and governance), Dynamic pressures -(education, urbanisation and population change) causing Unsafe conditions - poor quality housing and infrastructure, poverty

Themes in the Release model of the PAR model

Safety, Reducing the pressures, Addressing the root causes, Hazard mitigation

what does VEI stand for?

Volcanic Explosivity Index

Mini HIC volcano case study location

Eyjafjallajökull, Iceland (2010)

Eyjafjallajökull, Iceland (2010) VEI?

VEI 4 case study

Impact of Eyjafjallajökull eruption

No injuries or deaths, 700 people evacuated, Disruption of around 100,000 flights - costing airlines an estimated £130million a day (total cost €2.2 billion), (perishable goods ruined due to delay of flights contributing to unemployment in kenya) Flooding, contaminated local water supply with flouride, 110million^3 in tephra

Cost of flights delayed due to Eyjafjallajökull eruption

estimated £130million a day (total cost €2.2 billion)

Background info about Iceland

700,000 seasonal visitors, population of 360,000, flat land (glacial flooding), few roads, constructive/divergent plate boundary, cheap geothermal power

Mini NEE/LIC Volcano case study

Merapi, Indonesia (2010)

Merapi, Indonesia (2010) VEI?

VEI 4 case study?

Impact of Merapi, Indonesia (2010) eruption

353 deaths, 300,000 people evacuated, Crops destroyed - loss of £13 million, Food prices increased, Sulphur dioxide gas (from eruption) caused skin irritation and breathing problems, About 2,500 flights cancelled

Mount Merapi Indonesia plate boundary

destructive plate boundary

Other than being developed what are other reasons for different impacts in Mini eruption case studies

Population densities, There are a higher number of settlements around Mount Merapi, amounts of pyroclastic flow

what is pyroclastic flow?

term for really hot ash cloud that comes out of a volcano

what is tephra?

term for lumps of rocks falling from the sky because of the volcano

what is a lahar?

term for mud flow from a volcano (HOT

Mini earthquake EU case study

Amatrice, Italy (2016)

What are the impacts of the Amatrice, Italy (2016) earthquake?

296 deaths, 80% of buildings in the old town were affected, Over 50% of all buildings in were damaged and destroyed, school collapsed, landslides blocked roads, tourism negatively affected, hospital badly damaged, Cost of damage €23 billion, 400 were injured, and 4454 were homeless.

How many deaths, injuries due to Amatrice, Italy (2016) earthquake?

296 deaths, 400 were injured,

Magnitude of Amatrice, Italy (2016) earthquake

6.2 magnitude (rapid onset)

Depth of Amatrice, Italy (2016) earthquake

shallow depth of only 5.1 km (rapid onset only lasted 20s)

Population of Amatrice, Italy (2016)

Population of 2,500, however massive annual food festival so there were more people than usual in the area

Cost of damages in Amatrice, Italy (2016) earthquake

Cost of damage €23 billion,

HIC earthquake case study

Christchurch, New Zealand 2011

Background info about Christchurch

5 months before there was a earthquake so less likely for another one to happen, also created cracks and faults that the other one later exploited, Population 370,000, lots of old buildings

How many injured and killed in 2011 Christchurch?

6,000 injured and 185 deaths

depth and magnitude of 2011 Christchurch earthquake

5.1 km depth (shallow) and 6.3 magnitude

What was the cost of the Christchurch earthquake damages?

$30 billion

what is the boundary of the Christchurch earthquake?

Conservative plate boundary case study

Damages and impacts of Christchurch 2011 earthquake?

10,000 homes demolished, 40% of city "virtually unusable" 80% of water & sewage systems damaged, 10,000 people left the area, tourism fell by 30%, port destroyed, liquefaction of 15-20 m deep

% of city destroyed in 2011 Christchurch

40% "virtually unusable"

% of water and sewage infrastrucuture ruined in 2011 Christchurch?

80% damaged HIC case

LIC Earthquake case studies

Port au Prince Haiti or Gorkha Nepal

LIC 2015 earthquake case study magnitude

Gorkha nepal, 7.8

LIC 2010 eathquake case study magnitude

Port au Prince Haiti 7.0

Depth and time of Port-au-Prince Haiti 2010 earthquake?

13km deep 30 seconds rapid onset

Depth of 2015 Gorkha Nepal earthquake?

15 km deep

Deaths and injuries in the 2015 Gorkha Nepal earthquake?

Over 8,500 deaths, Over 20,000 people injured

What is the 2015 Gorkha plate boundary?

collision plate example

Other impacts of the 2015 Gorkha nepal earthquake?

Electricity and water supplies cut, 7,000 schools and 1,000 health facilities damaged or destroyed, Almost 3.5 million people displaced, Damages estimated at between US$7-10billion and about 35% of the GD

Reasons for the damages being so severe in the 2015 Nepal earthquake?

Monsoon season and deforestation weakened rock structure = mass movement and landslides. buildings not up to regulation, one of the poorest countries in the world - lacking funds and corruption delaying rebuilding and investing in infrastructure, rural areas not well educated

HIC tsunami case study

Japan 2011

Deaths and injuries in the 2011 Japan Tsunami

16,000 deaths, 6,000 people injured

Other impacts of the 2011 Japan tsunami

330,000 people homeless, Over 300,000 buildings destroyed, Economic cost estimated at US$235 billion, Damage to the Fukushima Nuclear power plant led to radiation leaks

LIC Tsunami case study

Indian Ocean (2004)

Deaths and injuries in the Indian Ocean (2004) tsunami

230,000 deaths, 650,000 people injured

Other impacts of the Indian ocean 2004 tsunami

1.7 million people homeless, 1500 villages in Sumatra destroyed, Tourism was negatively affected - in Thailand losses reached US$25 million a month, Total cost of economic damage estimated at US$9.4 billion

What is the difference between magnitude and intensity?

Magnitude is the amount of energy released. Whereas intensity is severity of ground shaking at a particular place based on the effects on humans, buildings and the environment.

How do you measure volcanic eruptions?

The Volcanic Explosivity Index (VEI), Measures - Height of material ejected into the atmosphere Volume of material, Duration of the eruption - Logarithmic scale from 0-8

What is a hazard profile?

measuring - Magnitude, Speed of onset, Areal extent, Duration, Frequency, Spatial predictability

Advantages of a hazard profile

Compare - Different hazards, Same hazards with different processes/boundaries, Same hazards with different human vulnerabilities - HIC vs LIC, OR to plan for future events

Disadvantages of a hazard profile

Other factors may have a greater influence on the impact, They focus on physical factors when human factors may be the most important, Multi-hazard events are not easily represented on a hazard profile, They are subjective

Haiti 2010 earthquake deaths and injuries

220,000 deaths, 300,000 injured

Haiti 2010 earthquake other impacts

1.5 million homeless, 70% of buildings collapsed, Disease spread Damages US$7.8 billion, Agriculture destroyed, Unemployment increased, Exports decreased

Define HDI and its purpose

Human development index is used to measure development in a country reflecting factors like - education, healthcare and income