Tectonics EQ1 Flashcards by NEVE BRADLEY

why are some locations more at risk from tectonic hazards

-live on a plate boundary
-population density
-level of development
-unstable government
-lack of preparation
-low infrastructure quality
-poor AID/ management
-secondary hazards

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why do tectonic plates move

-mantle convection
-slab pull
-subduction zone movement
-sea floor spreading

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Describe the crust

oceanic 6-10 km thick, continental <70km thick
up to 400°C. Solid state

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Describe the mantle

700-2890 km thick.
870°C.
upper part is solid and lower part is semi molten

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Describe the outer core

2890-5150 km thick
4400-6100°C
liquid iron and nickle

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Describe the inner core

5150-center km thick
7000°C (radioactive decay)
solid

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Describe divergent (constructive) plate boundaries (iceland)

two plates that move away from each other. They are most commonly found at mid oceanic ridges which causes sea floor spreading. when the plate separates new oceanic plate is formed because magma rises through the rift valley then hardens to form new crust. At this boundary you get shallow focus earthquakes submarine (under the sea) but these arent very powerful as less friction. Also get shield volcanoes here but they arent very explosive

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Describe convergent plate boundaries (oceanic-continental)

plates move towards each other then the denser plate (oceanic) slides below the other (continental). This happens in the subduction zone. here huge friction is generated between the two plate and deep ocean trenches appear. in the subduction zone, the lithosphere then melts and erupts out a composite volcano. Also when the energy.

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define the terms “basalt” and “andesite” and explain where they are typically found

basalt and andesite are both types of lava.
Basaltic lava: is typically found at shield volcanoes and ocean hot spots. it is thin and runny as it has a low viscosity and it has a low gas content. it is the hottest type of lava at 1000-1200°C.
Andesitic lava: is typically found at composite volcanoes. It is thicker than basaltic as it has a intermediate viscosity. It is less hot than basaltic lava at 800-1000°C but more explosive

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what is a Benioff zone and how does it relate to earthquakes

The Benioff zone is the area of seismic activity in the subduction zone. It is where pressure builds up between plates as they are moving due to friction then it gets released here causing an earthquake.

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what is pyroclastic flow

it is a primary hazard of a volcanic eruption. It is a mixture of ash lava and gases that runs quickly down the side of a composite volcano.

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what is lava flows

It is a primary hazard of a volcanic eruption. Lava travels down the side of a shield volcano and moves slowly

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what is tephra and ash cloud

it is a primary hazard of a volcanic eruption. tephra is fragmented material expelled during an eruption varying is size. Ash cloud is formed when the tephra is expelled and it can travel and surround building

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what are gas eruptions

it is a primary hazard of a volcanic eruption. Gases get emitted into the air. This can kill livestock and can be harmful to breath in. It can also cause the secondary hazard of acid rain

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what are lahars

It is a secondary hazard of a volcanic eruption. It is when ash and lava combines with water from lakes or rivers causing flooding

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what are jokulhlaups

It is a secondary hazard of a volcanic eruption. it is when lava meets a glacier causing it to melt resulting in flooding

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how many people died in the 2004 boxing day tsunami

300,000 deaths

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what was the cost of damages for the 2004 boxing day tsunami

$5.5 billion

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how many people lost jobs in the 2004 boxing day tsunami

2 million

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how much was given in aid in the 2004 boxing day tsunami

$700 million

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Factors affecting hazard risk for the 2004 boxing day tsunami

-no warning systems / unprepared
-9.0 magnitude
-poor infrastructure
-political insibility
-remote areas
-low level land
-series of waves with large wavelength
-low levels of development
-lack of education

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what was the magnitude of the 2004 boxing day tsunami

9.0

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what was the magnitude of the 2011 tsunami in japan

9.0

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how many people died in the japan 2011 tsunami

16,000

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what was the cost of damages for the japan 2011 tsunami

$230 billion

what was the hazard risk for the japan 2011 tsunami

-high population density near costlines -ageing population -such high magnitude -defenses failed -land subsided -vunerable infrastructure like a nuclear powerplant on the coast

what are P-waves

"primary waves" are a type of seismic wave generated by earthquakes

What is the difference between a hazard and a disaster

Hazard is the potential threat and disaster is the outcome. Not all hazards turn into disasters

Name some human factors that increase risk of a hazard becoming a disaster

-population density -government stability -level of development -location -preparedness -strength of infrastructure

What is vulnerability

The ability to anticipate, cope with, resist and recover from a natural hazard

What is resistance (capacity to cope)

The ability of a community or society exposed to hazards to resist, absorb and recover from the effects of a hazard

Describe the deggs model

Shows that’s when a vulnerable population and a hazardous event overlaps it can result in a disaster

What are the 5 key factors to explain why the relationship between risk hazards and people is so complex

Unpredictability Lack of alternatives Dynamic hazards Cost-benefit of staying put Russian-Roulette reaction

How does an aging population increase a countries risk

Affects a communities resilience. They may lack education as they have been out of school for so long. Less mobile so slower evacuation. May lack access to internet for alerts. Retired people do less to help economy and can’t afford repairs as much

What does that PAR model stand for

Pressure and release

What is the PAR model

Pressure from people and they’re vulnerability and release is ways to reduce pressure and vulnerability

What magnitude was the Haiti 2010 earthquake

7.0

How many people died in the Haiti 2010 earthquake

300,000

How many schools where damaged or destroyed in the Haiti 2010 earthquake

4000

What was the root causes of vulnerability in the Haiti 2010 earthquake

-heavily in debt to US, German and French banks -corrupt government -80% of population below poverty line

What was the dynamic pressures increasing vulnerability in the Haiti 2010 earthquake

Lack of: Urban planning Disaster preparedness Education systems Disaster management Also: Rapid urbanisation High population density Deforestation and soil degradation caused landslides

What was the unsafe conditions increasing vulnerability in the Haiti 2010 earthquake

-soft soil -illegal housing -low GDP -poor infrastructure -lack of access to safe water and sanitation

What city was the 2002 volcanic eruption in the DRC

Nyriagingo

What was the VEI of the eruption in Nyriagongo in 2002

What was the speed of onset in the Nyriagongo 2002 eruption

60kph

How many people were killed in the 2002 Nyriagongo eruption

250

How many people were made homeless in the 2002 Nyriagongo eruption

120,000

How many people have to evacuate to neighbouring countries in the Nyriagongo eruption

400,000

what are the social impacts of the Nyriagongo earthquake

deaths destroy 20% of homes forced to evacuate homelessness drinking acid rain

what are the economic impacts of the Nyriagongo earthquake

loss of income (farming) 2/4 hospitals destroyed tourism decline increased poverty agriculture loss

what was the magnitude of the 2008 Sichuan earthquake

7.9

how many people died in the 2008 Sichuan earthquake

87,000

how many people were displaced in the 2008 Sichuan earthquake

4.8 million

what was the reconstruction costs of the 2008 Sichuan earthquake

$147 million

what was the social impacts of the 2008 Sichuan earthquake

deaths displacement schools destroyed cultural loss- heritage sights

what was the economic impact of the 2008 Sichuan earthquake

infrastructure damage loss of agriculture reconstruction costs migration to urban areas

what was the magnitude of the 2001 japan tsunami

9.0

how many people were killed in the japan 2011 tsunami

20,000

how many people were made homeless after the 2011 japan tsunami

50,000

what was the cost of property damage in the 2011 tsunami

$360 billion

what are the social impacts of the japan 2011 tsunami

deaths homelessness psychological trauma education impact cultural loss health issues in temporary shelters

what are the economic impacts of the 2011 japan tsunami

infrastructure damage property damage disruption of industry e.g. manufacturing unemployment loss of tourism insurance claims

Tectonics EQ1 Flashcards

(63 cards)