P1 Section C (Hazards) Flashcards
What is a hazard
A hazard is a natural event when it occurs in the presence of a human
What is Automatic Disaster Analysis and Mapping System (ADAM)
Automatic Disaster Analysis and Mapping System (ADAM) is a way to see the scale of a disaster by collating data from US Geological Survey, World Bank and World Food Programme
How to predict hazards
Can predict hazards by remote sensing and seismic monitoring
Parts of hazard management cycle
Hazard management cycle parts include preparedness, response, recovery and mitigation
What is preparedness part of hazard management cycle
preparedness part of hazard management cycle includes education and public awareness which gives people knowledge to speed up response process
What is response part of hazard management cycle
response part of hazard management cycle is emergency plans put in place to give medical assistance and assessing damage to help plan recovery
What is recovery part of hazard management cycle
recovery part of hazard management cycle is restoration to the pre-event level infrastructure and services
What is mitigation part of hazard management cycle
mitigation part of hazard management cycle is strategies to lessen effects of another hazard (like warning signals created or long-term coral reeves being developed)
What is fatalism
Fatalism is the view that hazards are uncontrollable and losses should be accepted since nothing can be done about them
What are the three major types of geographical hazards
three major types of geographical hazards are geophysical, atmospheric and hydrological
Type of geophysical hazard
Geophysical hazard is volcano
Type of atmospheric hazard
Atmospheric hazard is wildfire as caused by certain weather conditions
Type of hydrological hazards
Hydrological hazard is floods
Where is Sichuan
Sichuan is in a mountainous region of western China
When was Sichuan Earthquake
Sichuan earthquake was in 2008
What magnitude was Sichuan EQ
Sichuan EQ was 7.9 magnitude
What was depth of Sichuan EQ
Depth of Sichuan was 19km
What caused Sichuan EQ
Sichuan EQ caused by destructive plate boundary between two continental crusts
Social impacts of Sichuan EQ
Social impacts of Sichuan EQ include 70,000 deaths and 4.6 million homeless and protests due to poor infrastructure and lack of earthquake-proofing particularly in schools
Environmental impacts of Sichuan EQ
Environmental impacts of Sichuan EQ include lost panda habitats and quake lakes causing excessive flooding which also altered water flow so some areas were starved of water
Economic impacts of Sichuan EQ
Economic impacts of Sichuan EQ include losses of $150 billion and 14,000 industrial companies were damaged ( which make up 45% of its GDP) and grain price increased for 2 years
Residents local response to Sichuan EQ
Residents local response to Sichuan EQ was to protest in anger of lack of preparation which was successful as government now set up action plans, survival kits, shelters and EQ proof buildings
National response to Sichuan EQ
National response to Sichuan EQ was Chinese leaders promise £5 billion to rebuild the area
International response to Sichuan EQ
International response to Sichuan EQ was habitat for humanity worked on housing projects to help 1,000 families and it was completed in 2010 and Germany were biggest monetary aid donator with $31 million
What is liquefaction
Liquefaction is when saturated or partially saturated soil is shaken by an earthquake causing water to rise and soil loses strength so buildings sink or tip over
What are the layers of the earth
Layers of the earth are crust, mantle, outer core and inner core
What is crust
Crust is 5-70km thick rock either oceanic or continental
What is oceanic crust
Oceanic crust is an occasionally broken layer of basaltic rock known as sima
What is continental crust
Continental crust is bodies mainly made of granitic rock known as sial
What is lithosphere
Lithosphere is a zone made up of crust and upper mantle where tectonic plates form
What is asthenosphere
Asthenosphere is a softer rock which the solid upper mantle sits on and the asthenosphere can move
What is the mantle
The mantle is a 2900km thick layer made of silicate materials and is semi-molten due to convection currents
What is the core
The core is the centre of the earth reaching over 6000 degrees Celsius and is made of iron and nickel and is four times the density of the crust
How do tectonic plates move
Tectonic plates move by convection currents in asthenosphere which pull and push plates in different directions
What occurs at destructive plate margins
At destructive plate margins plates move towards each other
What happens when continental and oceanic plates meet at destructive margin
when continental and oceanic plates meet at destructive margin the denser oceanic plate subducts and leaves a deep ocean trench and the plate melts away which increases magma and so increases pressure which forces through weak areas in the continental plates as composite volcanoes
What happens when oceanic and oceanic plates meet at destructive margin
when oceanic and oceanic plates meet at destructive margin the heavier plate subducts leaving an ocean trench and built up pressure leads to underwater volcanoes and lava cools and creates island arcs
What happens when continental and continental plates meet at destructive margin
when continental and continental plates meet at destructive margin the continental crust piles up on top of the lithosphere due to pressure and fold mountains form
What occurs at constructive plate margins
At constructive plate margins, plates move away from each other
What happens when oceanic and oceanic plates separate at constructive margin
When oceanic and oceanic plates separate at constructive margin magma rise in the gap left by separation which forms new land which is called sea floor spreading as the floor gets wider and underwater volcanoes form due to rising magma
What happens when continental and continental plates separate at constructive margin
when continental and continental plates separate at constructive margin, rift valleys form as land in the middle of the separation is forced apart and water will often fill the valley and volcanoes may form as magma rises
What is ridge push
Ridge push is when magma from mantle pushes out the plates surrounding a ridge on a constructive margin
What is slab pull
Slab pull is when a plate subducts and the rock sinking into the mantle pulls the rest of the slab with it, causing further subduction
What is gravitational sliding
Gravitation sliding is the accumulation of slab pull and ridge push
What occurs at conservative plate margin
At conservative plate margin, parallel plates move in different directions at different speeds and no plates are destroyed so there’s no landforms created
What happens when oceanic crusts are at conservative margin
when oceanic crusts are at conservative margin pressure builds up and water can be displaced by earthquakes
What happens when continental crusts are at conservative margin
when continental crusts are at conservative margin, fault lines can occur where the ground is cracked by movement
What is the Benioff zone
The Benioff zone is the area of a destructive plate margin where melting of the less dense oceanic crust
Example of fold mountains at destructive margin
Example of fold mountains at destructive margin are the Andes and the Himalayas
What is the Mariana Trench and Mariana Islands
The Mariana Trench and Islands are an example of subduction where the oceanic plate sinks below the continental crust and then crescents of submarine volcanoes to form islands
Example of sea floor spreading
Example of sea floor spreading is either side the Mid-Atlantic ridge
Example of rift valley
Example of rift valley is the Great African Rift Valley
What are hotspots
Hotspots are areas of volcanic activity unrelated to plate boundaries where hot magma plumes from the mantle rise and burn through weaker parts of the crust to form shield volcanoes and islands
How do magma plumes create chain islands
magma plumes create chain islands as they remain in the same place whilst the plates move so volcanoes can dot around like in Hawaii
All hazards of volcanoes
All hazards of volcanoes are lava flows, lahars, glacial floods, tephra, toxic gases and pyroclastic flow
What is viscosity
Viscosity is a fluid’s resistance to flowing and silica makes lava viscous and slow which is common in explosive eruptions
What are mudflows
Mudflows are when ice and snow are melted by magma heat which causes quick discharge of water typically at high altitudes where there is substantial supply of ice and snow and the lahar will flow down a valley slope into a river
What is tephra
Tephra is all pieces of all fragments of rock ejected into the air by an erupting volcano. Most tephra falls back onto the slopes of the volcano, enlarging it.
What are toxic gases
Toxic gases are gases like sulphur dioxide which can form acid rain in atmosphere
What is pyroclastic flow
Pyroclastic flow is the clouds of burning hot ash and gas that collapses down a volcano at high speeds typically 60mph but can reach 430mph
How is seismic activity measured to predict volcano
seismic activity is measured to predict volcanoes by seismometers which detect microquakes indicating magma fracturing and cracking overlying rocks
How is ground deformation measured to predict volcano
ground deformation is measured to predict volcano by using tilt meters to show inflation of the ground caused by rising magma
How is movement of iron-rich magma measured to predict volcano
movement of iron-rich magma is measured to predict volcano by magnetometers which show changing magnetism inside a volcano indicating rising magma
How is gas content measured to predict volcano
gas content is measured to predict volcano by thermal imaging and gas sampling to show increasing emissions like poisonous chlorine
How frequent are volcanoes
Volcanoes are very frequent, with around 50-60 eruptions every month and volcanoes are classed as active, dormant or extinct
What does frequency of volcano indicate
frequency of volcano indicates type of eruption: high frequency volcanoes are usually effusive where low frequency volcanoes are explosive
How regular are volcanoes
Volcanoes are regular in the sense that the same eruptions will occur on each type of boundary, like a volcanoes on a destructive margin will regularly be explosive
How predictable are volcanoes
Volcanoes are fairly predictable by following timelines of eruptions, looking at seismic activity, ground deformation, gas samples and movement of magma
Location of Eyjafjallajokull
Location of Eyjafjallajokull is a subglacial volcano in Southern Iceland caused by separating European and North American plates
When did Eyjafjallajokull erupt
Eyjafjallajokull erupted 2010
Primary impacts of Eyjafjallajokull
Primary impacts of Eyjafjallajokull were meltwater washed away a perimeter road and released 150,000 tonnes of CO2 every day
Secondary impacts of Eyjafjallajokull
Secondary impacts of Eyjafjallajokull were closed airspace for over a week losing airlines $1.7 billion in revenue, disrupted travel for 10 million people and Kenyan farmers were laid off as their fresh produce couldn’t travel to Europe by cargo or freight and also there was around 2 million tonnes of C02 saved due to cancelled air travel
How was Iceland prepared for the Eyjafjallajökull eruption
Iceland was prepared for the Eyjafjallajökull eruption as a team used GPS and satellite radar interferometry to find one flank was swollen 11 weeks prior implying magma had been rising
How did Iceland respond to Eyjafjallajokull
Iceland respond to Eyjafjallajokull by closing airspace and Icelandic Red Cross evacuated people and sheltered 200
Location of Montserrat volcano
Montserrat volcano is an island within the northern part of the lesser Antilles where the Caribbean plate subducts beneath the South American plate
When did Montserrat’s stratovolcano erupt
Montserrat’s stratovolcano erupted 1997
Death toll of Montserrat 1997
Death toll of Montserrat 1997 was 19 people
Primary impacts of Montserrat 1997
Primary impacts of Monsterrat 1997 was 5 million cubic metres of hot rock and ash and 3/4 of infrastructure destroyed and the airport was destroyed
Secondary impacts of Montserrat 1997
Secondary impacts of Montserrat 1997 are 11,000 evacuated to Antigua, UK and USA
How was Montserrat prepared for the 1997 eruption
Montserrat was prepared for the 1997 eruption as the Montserrat Volcano Observatory was set up in 1995 and predicted the eruption
Short-term responses to Montserrat 1997
Short-term responses to Montserrat 1997 were exclusion zones in 2/3rds of the island, troops from USA and British Navy aided in evacuation and £17 million in UK aid paid for temporary buildings and water purification
Long-term responses to Montserrat 1997
Long-term responses to Montserrat 1997 were 3 year redevelopment programme for houses, agriculture and medical services funded by UK, people of Montserrat were granted full residency rights in UK in 1998 and UK financial aid has exceeded £420 million since 1995
How has Montserrat 1997 changed demographic of island
Montserrat 1997 changed demographic of island as many young people seen no future on the island and migrated, resulting in a dependent population (many old people)
Location of Mount Etna
Location of Mount Etna is on the Italian island of Sicily and resulted from the collision between the African and Eurasian plate
How does Mount Etna support Sicily
Mount Etna supports Sicily as 25% population lives on the volcano’s slopes and its fertile volcanic soil supports agriculture like vineyards and orchards spread across the lower slopes
What type of volcano is Mount Etna
Mount Etna is a stratovolcano, a decade volcano and has Strombolian type eruptions with short lava flows near the summit
Impacts of Mount Etna
Impacts of Mount Etna are estimated 77 deaths, increased cardiovascular morbidity especially among the elderly, 3 million tourists in 2010, and eruptions in 2018 cost $115 million
Responses to Mount Etna
Responses to Mount Etna are in 2002 there was tax breaks for villagers due to damages to agriculture, in 2001 and 2014 Catania airport was closed, in 1992 US Army helicopters dropped concrete blocks into lava tubes and in 2013 the Italian government gave £5.6 million worth of aid
Mitigation strategies for mount Etna
Mitigation strategies for mount Etna include artificial lava channelling to direct lava flow safely, in 1990s earth barriers were constructed to divert lava and there is constant monitoring by etna observatory
