Natural Hazards (paper 1) Flashcards
what are the four categories of hazards
- atmospheric
- geomorphological
- tectonic
- biological
what are atmospheric hazards
weather and climate related (hurricane, drought)
what are geomorphological hazards
land surface hazards (sinkhole, landslide)
what are tectonic hazards
linked to movements in the earth’s curst (earthquake, volcano)
what are biological hazards
relating to plants and animals (forest fires)
define natural hazard
a natural event that causes loss of life and/or damage to property
what is the difference between a natural event or hazard
an event just happens and there is no loss of life, a hazard kills and damages
what two categories of hazards are geological
tectonic and geomorphological
what two categories of hazards are meterological
atmospheric and biological
define geological hazard
caused by land and tectonic processes
define meteorological hazards
caused by weather and climate
what name is given to a colour key map of the world
choropleth map
are earthquake loactions associated with plate boundaries
yes highly
are volcano locations associated with plate boundaries
yes extremely
are tropical storms associated with plate boundaries
no - they only occur close to the equators
what factors affect hazard risk
- more densely populated areas and countries
- buliding on hazardous lands (flood plains / volcano surroundings)
- relief of the land
- climate change (warmer = more intense storms)
- poverty (forces people to live in hazardous areas)
- topography of land
- magnitude and frequency of an event
- location (on tectonic plate)
define hazard risk
the chance or probability of being affected by a natural hazard
what are the two different types of effects
- primary
- secondary
what are primary effects
an impact or effect of a hazard that occurs as a direct consequence of that hazard (roof tiles falling off / death)
what are secondary effects
hazards that result from an initial event but happen at a later date (diseases / mudslides / ash clouds)
why do people live in hazardous areas
- geothermal energy sources (volanic areas) - iceland & italy
- desired climate
- soil fertility (volcanic areas) - tomatoes in iceland
- resources underground (diamonds) - america
-tourism - blue lagoon Iceland - earthquakes are coastal - helps for fishing
what is the radius (distance from the centre) of earth
6300 km
how many large tectonic plates are there
7
describe the mantle of the earth
- widest & thickest layer
- high viscosity on outside
- low viscosity closer to middle
what are the three plate theories
- convection currents
- ridge push
- slab pull
explain convection currents
- magma near the core is heated up and rises
- magma reaches the crust and cools as spreads sideways
- sinks towards the core dragging the crust above it
- cycle continues
explain the ridge push theory
at constructive boundary
- magma rises
- magma cools to form new oceanic plate material
- forms mountain ridge
- it is very dense and slides down away from the ridge
- this causes tectonic plate to move away from each other
the weight of the ridge pushes the rest of oceanic plate in front of it
explain the slab pull theory
at destructive plate boundary
- denser oceanic plate sinks back into the mantle under gravity
- pulls on the rest of oceanic plate behind it & speeds up
what are the three peices of evidence to continental drift
- study of fossils
- pattern of rocks
- shape of continents fit
what are the two different types of crust
- oceanic
- continental
what are the characteristics of oceanic crust
- younger
- thinner
- heavier (dense)
- temporary = constantly being destoryed and replayed
what are the characteristics of continental curst
- older
- lighter
- pernament = cannot be destroyed
when was Pangaea
250M years ago
explain how the study of fossils is evidence for continental drift
- dinosaus found in Antartica, India & Africa
- land mammel and cannot swim
= no other explaination
explain how the patterns of rocks is evidence for continental drift
- same rocks of same age found in East Canada & West Scotland
- rocks were once very close or joined
explain how the shapes of continents fitting is evidence for continental drift
- south America and Africa
- they were once together
what are the four types of plate boundaries
- conservative
- destructive (convergent)
- constructive (divergent)
- collision
describe a conservative plate boundary
- when two plate boundaries move past each other = strike-slip fault = built up friction released
- San Andreas faults, California
- violent earthquakes
- NO VOLCANOES
describe a destructive plate boundary
- oceanic plate boundary is subducted by continental as it is denser
- Japan
- composite volcanoes (rare violent & steep)
- fold mountains
- earthquakes
describe a constructive plate boundary
- 2 oceanic plates move away from each other = rising magma forms new crust
- mid-Atlantic ridge
- sheild volcanoes (frequent gentle & flat)
- gentle earthquakes (due to less energy)
describe a collision plate boundary
- 2 continental plates collide & cannot sink into mantle
- Himalayas mountain-range
- earthquakes
- fold mountains
what are the two types of volcanoes
- sheild volcanoes
- composite volcanoes
explain and describe sheild volcanoes
- found at constructive plate boundaries
- made up of layers of cooling lava
- fast flowing
- frequent but gentle eruptions
- gas escapes easily
- wide and gentle sloping
- eg Mauna Loa, Hawaii
explain and describe composite volcanoes
- found at desstructive plate boundaries
- made up of layers of ash and lava
- slow flowing, sticky lava
- gas builds up = violent
- steep sides
- melting oceanic plate
- secondary vents
- eg Mount Etna, Italy
describe how volcanoes are distributed globally
- most commonly found overall on plate boundaries
- Pacific Ring of Fire
- mid-Atlantiic ridge
- anamolie = Hawaii ~ hotspot
- anamolie = not all plate boundaries = conservative X!
descirbe how earthquakes are distributed globally
- all plate bounaries
- human activity + risk ~ mining
- Pacific Ring of Fire
- anamolie = Hawaii ~ volcanic hotspot activity
what is actuall meant by the term earthquake
the seismic waves felt during plate movement at plate boundaries
define focus of an earthquake
the exact point in the Earth’s crust where the earthquake started ~ deeper focus = lower magnitude
define the epicenter of an earthquake
the exact point directly above the focus on the Earth’s surface ~ closer to epicenter = higher magnitude felt
why do earthquakes occur
- friction at plate boundaries
- built up pressure released quickly
- huge pulses of energy let out
- Earth’s surface moves violently
what are the 2 scales for measuring an earthquake
- the Richter Scale
- the Mercalli Scale
what is the Ritcher Scale
- scale from 0-10
- a logorithmic scale on energy & movement (increased massively per number)
- measured using seismograph
what are your 2 named examples of an earthquake
- HIC = Chile 2010 ~ 500 dead
- LIC = Nepal 2015 ~ 9000 dead
compare the GDP of Chile and Nepal
- Chile = 38th / 193
- Nepal = 109th / 193
give context to the Chile 2010 earthquake
- 8.8 magnitude
- off coast of central Chile
- desructive plate margine = deep benioff zone
- Tsunami warnings
- 500 dead
- $30Billion
give context to the Nepal 2015 earthquake
- 7.9 magnitude
- epicenter 60km NW from capital Kathmandu
- focus only 8km deep
- collision plate boundary
- $5Billion
- caused avalanches on Everest
give the primary effects of Nepal’s 2015 earthquake
- over 8M affected
- 3M homeless
- 7,000 schools destroyed
- 50% shops destroyed
give the secondary effects of Nepal’s 2015 earthquake
- Avalanches & landsides
- 19 dead on Mt Everest
- River blocked = floods
- tourism declined
- farmers could not harvest rice for over a year
what was worse for Nepal? the primary or secondary effects & why
primary - more deaths and caused social & economic longerm effects - very poor QoL for long time
give the primary effects of Chile’s 2010 earthquake
- over 800,000 affected
- 220,000 homeless
- 4500 schools destroyed
- travel severly impacted
give the secondary effects of Chile’s 2010 earthquake
- tsunami waves devastated several towns
- fire at chamical plant
- landslifde destroyed 1500km of roads
what was worse for Chile? the primary or secondary effects & why
primary - infrastructure destroyed = social impact, schools destroyed = cannot function as usual, caused deaths ~ secondary = no deaths
give the immediate response of Chile’s 2010 earthquake
- emergnecy services responded quickly
- international support = field hospitals, floating bridges
- route 5 temporarily repaired in under a day
- in 10 days 90% homes had power & water
- country raised $60M for emegency shelters
give the long term responses of Chile’s 2010 earthquake
housing reconstruction plan helped 200,000 families
what was better in Chile? the immediate or long term responses? why?
the immediate - helped most citizens at the time, immediately back on feet, long term good too but not as good
give the immediate responses of Nepal’s 2015 earthquake
- India & Chine provided $1Billion
- three helicopters given
- UK pprovided over 100 rescue responders
- temporary housing = ‘tent city’
- Facebook launed a saftey feature
give the long term responses of Nepal’s 2015 earthquake
- stricter building codes introduced
- thousands rehoused
- over 7000 schools rebuilt
- repairs in Everest camps
- many countries donated millions
- lakes were damed
- landslides cleared
what was better in nepal? the immediate or long term responses? why?
longterm - socailly ~ schooling, travel back, economically ~ tourism back, future ~ prevention methods put in place, government helped very little
what are the four ways to reduce risk from tectonic hazards
- monitoring
- prediction
- planning
- protection
explain how monitoring is used to reduce tectonic hazard risk
- measure gas emitions (sulfure dioxide) from volcanoes
- GPS measure falling & rising land
- ground deformation = changes in shape
- seismographs
- not availiable globally
explain how prediction is used to reduce tectonic hazard risk
- using hisotrical evidence
- earthquake chains along fault lines
- radon gas emitted before eruptions
- seismonitor = fore-shocks
- earthquakes harder to predict
explain how planning is used to reduce tectonic hazard risk
- identifying and avoiding high risk areas
- volcanic hazard maps
- procedures practiced ~ under tables etc
- survival plans
- specific architecture to withstand hazards
- not availiable globally = expensive
explain how protection is used to reduce tectonic hazard risk
- building embankments to diver lava flow
- rubber shock absorbers in foundations
- concrete ring ties on walls
- latice work frames on building walls
- more earthquake based ~ expensive
what is the global atmospheric circulation model
the movement of air along the earth’s surface
why is the equator hot
the suns energy is concertrated on a small area
there is less atmosphere to travel through
= hotter
what is the thermal equator
the belt encircling the earth which shifts slightly north and south - creating the seasons
what are the three cells of earth
- Hadley cell
- Ferrel cell
- Polar cell
describe the Hadley cell
- between 0°-30°
- low pressure at 0° and high pressure at 30°
- warm, moist air rises at equator
- air sinks = high pressure causing a desert environment
describe what happens at the hadley cell
- warm moist air rises at the equator
- warm air cools and condenses = clouds and rain = tropics
- cool, dry air sinks at around 30° N and S
- The sinking dry air warms and evapourated any available water = deset
- warming dry air returns back to equator along the surface of the earth
describe the Ferrel cell
- between 30°-60°
- highpressure = 30°, lowpressure = 60°
- creates the polar front as some air blows towards the poles
- warm and cold air collide and froces upwards
describe the polar cell
- between 60°-90°
- air is cooled and sinks = cold desert
- 60° = lowpressure, 90° = highpressure
- no precipitation
what is the coliolis effect
when winds curve due to the earth’s rotation
what are horse latitudes
windless strip of hot, dry air at 30°
what are doldrums
a band of hot, dry air around the equator - no wind
why do we have seasons
because the thermal equator moves die to the Earth’s 23.5° tilt throughout the year
where are the westerlies
surface winds between 30° and 60° north and south
where is the polar front
surface winds between 60° and 90° north and south
where are the southeast trade winds
between 0° and 30° south
where are the northeast trade winds
between 0° and 30° north
which direction do westeries go
right
which direction do trade winds go
left
which way do polar fronts go
right
what drives extreme weather events like tropical storms
trade winds drive them as the thermal equator moves over more oceans
what is used to measure wind speeds
anometers
is a storm surge a primary or secondary effect
secondary
what is a storm surge
when the sea is pushed onto land by incredibly stron winds
what is the difference between a tropical storm, hurrican, cyclone and typhoon
location
where do tropical storms happen
5° - 30° - mostly america - form on the atlantic ocean
where do typhoons happen
mostly Japan and philipeans - form on the pacific ocean
where do cyclones happen
India, Sri Lanka, East Africa - form on the Indian Ocean
what is the difference between a tropical storm and a tornado
tornadoes are on land - tropical storms are water bases and then make land therefore losing engery
why can tropical storms not form on the equator
due to the coriolis effect = low pressure = air rises = no surface wind
what is the name of the scale which measures tropical storms
Saffir-Simpson scale
what is the Saffir-Simpson scale base on
wind speeds
catergory 5 = 157+ mph
what is the name of the centre of a tropical storm
the eye
what is the name of the windy part of the tropcial storm
the eye wall
is the eye of the storm calm or eratic
calm
what conditions are needed for a tropical storm to form
- sea temperature about 26°C at 50m deep
- thunderstorm cluster
- light wind shear
how has and how will distribution of tropical storms change
- sea temps have increased by 0.5°C
- will move further north and south
- eg Hurrican Caterina (2004) Brazil’s first catergory 2
how has and how will the frequency and magnitude of tropical storms change
- will be less frequent but much higher magnitude
- from warmer water over ocean
- can only have one at a time so they will merge and me bigger
what are the physical things which impact a tropical storm
- repeated events
- warmer air
- relief of land
- track of strom (over land lots = weak)
- sea levels rise
- latitiude
- urbanisation
how can you manage tropical storms through monitoring
- NASA satellites monitor cloud patterns
- global Hawk drones monitor weather patterns
how can you manage tropical storms through prediction
- supercomputers can give 5 day warning
- track forecast cone can plot the predicted path
- early warnings issues by national hurrican centre
how can you manage tropical storms through protection
- windows, doors and roofs reinforced to stregthen buildings to withstand strong winds
- storm drains constucted in ubran areas to take away excess rainfall
- storm shelters created
- sea walls to weaken storm surge
how can you manage tropical storms through planning
- community awareness of how to respond
- families have plans of action
- planned evacuation routes
what is the tropical storm case study (give details)
- Typhoon Haiyan
- In the Philippines
- in November 2013
- 4th most intense ever recorded
which effects were more significant in Typhoon Haiyan primary or secondary
primary
give the primary effects of Typhoon Haiyan
- more than 10,000 dead
- 90% of Tacloban completely destroyed
- 30,000 fishing boats destroyed
- no power, medicine
give the secondary effects of Typhoon Haiyan
- storm surge 15m high
- 4.1M left homeless
- flooding resulted in landslides
which responses were more significant in Typhoon Haiyan immediate or longterm
longterm
give the longterm responses to Typhoon Haiyan in the Philippines
- rebuilding roads, bridges and airports
- UN donated finacial aid & medical support
- rice farming & fishing = quickly reestablished
- more cyclone shelters made
- thousands of homes rebuilt away from areas at risk from flooding
give the immediate responses to Typhoon Haiyan in the Philippines
- UK government sent shelter kits
- over 1200 evacutation centres
- US aircraft carrier and helicopters
- field hospitals
since when has the quaternary period been
the last 2.6 million years
what are the two types of periods we have flucuated between over the last millions of years
- inter-glacials
- glacials
what are glacials and inter-glacials
- glacials = cold = ice ages
- inter-glacials = warm
how much has the avergae global temperature rises and since when
since the 1800s it has riased by 0.85°C
what are the three greenhouse gases
- water vapour
- methane
- carbon dioxide
what usually lasts longer: inter-glacials or glacials
glacials
what are the three peices of evidence for climate change
- proxies / indirect data (ice cores)
- shrinking glaciers and melting ice
- rising sea levels
how are proxies / indirect data (ice cores) evidence for climate change
- as snow falls it preserves gases in it
- scientists can study the oxygen in ocean sediments
- and they can be accurated dated
how are shrinking glaciers and melting ice evidence for climate change
- glaciers are retreating
- estimated some may disappear by 2035
- Artic sea ice has thinned by 65% since 1975
how is rising sea level evidence for climate change
- average global sea level has risen 10-20cm in the past 100years
- tempertures increases = water melts = more water flows into sea
- ocean water warms - expands in volume ~ thermal expansion
- temperatures rise = rather than snow falling rain is on glacier
what are the natural causes of climate change
- volcanic activity
- solar activity
- Milankovitch’s orbital cycles
what have humans caused to happen in the atmosphere which ahs resulted in more heat and radiation inside the atomosphere
- thicker layer of greenhouse gases
- = a lot of sun radiation re-absorbed and reflected to earth
what are the human causes of climate change
- burning fossil fuels
- agriculture
- deforestations
describe how volcanic activity causes climate change
- super volcano erupts
- volcanic ash blocks out the sun = less radiation
- sulfur dioxide becomes sulfric acid in the air
- dropletes reflect radiation from sun for a long time
- leads to a volcanic winter
- eg 1815 Mount Tambora in Indonesia caused 0.5°C decrease, year without a summer, 200000 dead from loss of crops
describe how burning fossil fuels causes climate change
- accounts for 50% of our greenhouse gas emissions
- coal, oil and gas burnt for electricity, energy, industry
- releases carbon dioxide = less radiation re-radiated
- eg 1750 = 30% increase of CO2
describe how solar activity causes climate change
- there is an 11 year sun spot cycle
- sun spots are dark patches on the sun which is maximum radiation
- more sunspots = warmer from more radiation
- eg 1645-1715 = very few sunspots = ‘The Little Ice Age’
describe how agriculture causes climate change
- accounts for 20% of our gas emissions
- gas’s are emitted from farming and cooking
- larger population = higher demand for meat
- as wealth increases so does diet = more meat
- therefore more methane produced and more CO2 sinks lost from farming crops
describe how deforestation causes climate change
- logging and clearing land for agriculture means deforestation
- trees are carbon sinks = store CO2
- trees remove CO2
- cutting them = less CO2 removed and the CO2 they store is released
- = more radiation absorbed back by the greenhouse gas layer
what are Milankovitch’s orbital cycles
- eccentricity
- axial tilt
- precession (complex dont refer to in a 6/9 marker)
what is the eccentricity orbital cycle and how does it cause climate change
- it is the shape of earth’s orbit around the earth
- circular orbits = colder, eliptical orbits = warmer
- because the earth passes closer to the sun on eliptical orbits
what is axial tilt and how does it cause climate change
- there is a 42,000 year cycle of tilts
- the earth is currently at 23.5°
- 21° tilt = cold periods
- 24.5° tilt = warm periods
how does climate change effect the environment
- more forest fires
- warmer rivers = change ecosystems
- islands will be flooded = kill animals
- warmer temps = glaciers shrink = loss of habitat
- increased drought
- coral reefs bleeching from rising ocean temps
how climate change effects the people
- water scarcity
- more extreme weather = destruction & death = more insurance claims
- environmental refugees = people forced to migrate = overpopulated elsewhere
- skiing industry decline ~ less snow
- some farmers will grow more and some less depedning on location = malnutrition
what are the two types of ways of managing climate change
- mitigation
- adaption
give the mitigation ways of managing climate change
- planting trees (afforestation)
- carbon capture and storage
- alternative energy production
- international agreements
how does afforestation manage climate change
- trees act as carbon sinks and remove CO2
- they take a long time to grow
how does carbon capture and storage manage climate change
- technology on chimneys of power stations captures 90% of CO2 and stores underground
- expensive, complicated and only stops CO2
how does using an alternative energy production method manage climate change
- uses renewable energy resources rather than the ones which produce greenhouse gases
- nuclear, wind, solar…
- everything is built for fossil fuels and renewable resources are not reliable
how do international agreements help manage climate change
- countries come together to discuss climate change in a common goal
- lots of dispute and LICs feel as if they cannot develop
give some examples of international agreements to manage climate change
- 2005 kyoto agreement = 170 countries
- 2015 paris agreement = 195 countries to keep global temps less than 2°C rise - largest producers not involved (russia, USA)
give the adaptation ways of managing climate change
- reducing risk
- changing agriculture
- managing water supply
how does reducing risk manage climate change
- by relocating people and building sea walls, houses on stilts… people are less effected by the results of climate change
- fresh water supplies will be contaminated by sea water
- expensive
how does changing agriculture manage climate change
- by using different crops types and farming methods plants can be modified to resist impacts of climate change
- eg drought resistant GM crops
- expensive and doesnt solve the initial problem
how does managing the water supply manage climate change
- by using less water and transporting it to places in deficit then less water is needed
- use water meters
what is the UK weather hazard
The Beast from the East, 2018
what causes the Beast from the East
- a change to the northern polar jet stream:
- temps rised in artic and air sinks through the atomsphere
- cold air brings a chill and picks up moisture resulting in snow
give some primary effects of the beast from the east
- 10 killed across country
- trains cancelled = no business
- crop & livestock died
- thousands of schools closed
- gas deficit warning
give some secondary effects of the beast from the east
- hundreds of people trapped in vehicles due to traffic
- british airways cancelled hundreds of flights
- rush of supermarket customers
- many lorries crashed or jack knifed
define extreme weather
weather that is especially sever / beyond usual weather patterns
give the responses to manage the beast from the east
- stranded drivers were given foil blankets
- gritters and snow ploughs sent out]
- greggs gave out free food to stranded drivers
- ‘red warnings’ issuedd by met office
- army called to help
