Natural Hazards Flashcards
define a natural hazard
a natural process which could cause death, destruction or disruption to humans or destroy property.
give three factors affecting a hazard risk
- vulnerability
- capacity to cope
- nature of natural hazards
name the type of plate boundary where two plates are moving towards each other
destructive plate boundary
name the type of plate boundary where two plates are moving sideways against each other
conservative plate boundary
why do volcanoes form at destructive plate boundaries
- denser oceanic plate forced down when they collide
- plate melts making magma
- magma rises, cracking the folded continental plate
- magma rises into the hole in plate and volcano is formed
at which type of plate boundaries can earthquakes occur at
all boundaries:
- destructive
- conservative
- contructive
give an example of an earthquake in a RICHER part of the world (location, date, magnitude)
- l’aquila, italy
- 6th april 2009
- 6.3 richter scale
describe three primary effects of an earthquake in a RICHER part of the world
- 300 people died (families without income/emotional trauma)
- landmarks collapsed (tourism rate reduced, less income)
- hospitals evacuated (injured couldnt be treated/worsens injuries- infections/further disease?)
give an example of an earthquake in a POORER part of the world (location, date, magnitude)
- nepal
- 25th april 2015
- 7.9 richter scale
describe three primary effects of an earthquake in a POORER part of the world
- 9000 died (families without income/emotional trauma)
- 50% schools destroyed (lack of education/ unqualified for jobs)
- reduced supply of food, work and electricity (quality of life reduced/cant support families)
why do people live in places prone to tectonic hazards
- moving large numbers of people would be impractical
- jobs are plentiful near volcanoes
- tourism attracts thousands of people (eg mount Etna)
- volcanic soil is fertile (mt Vesuvius grows olive trees)
describe global atmospheric circulation
- warm air rises at equator
-similar air mass on other side of equator forces other air mass to move north creating low pressure zone
cools & sinks at 30*N then travels south back to equator and along replacing air that rose previously
describe the distribution of tropical storms
- 5-25 north and south of equator
- mainly found over oceans
what conditions are required for a tropical storm to develop
- 27*C sea
- 5* - 25* north and south of equator
- 60-70m deep sea
- summer and autumn
in what direction does a tropical storm develop? which way does it move?
- because of the coriolis effect, tropical storms spin anticlockwise in the northern hemisphere
- in the southern hemisphere they spin clockwise
what can cause a tropical storm to lose strength
- land (no energy from the sea)
- if sea cools down (not 27’C anymore)
describe three characteristics of the eye of tropical storm
- 50km across & caused by descending air
- low pressure, high temp
- no clouds or rain
how might climate change effect tropical storms
warmer temp causes sea temp to rise
- more areas of oceans above 27’C, more places experience tropical storms
- oceans 27’C more often, no. of storms increase
- higher temp = more energy for storm, stronger storm = more damage
using an example, describe three PRIMARY effects of tropical storms
- 6000 people killed
- 400mm of rain (widespread flooding)
- Airport was badly damaged (no money from tourism)
using an example, describe three SECONDARY effects of tropical storms
- Shortages of food and water (outbreaks of disease)
- Jobs, schools and hospitals damaged (disrupting livelihood)
- Flooding caused landslides (cut off aid)
using an example, describe the IMMEDIATE responses to a tropical storm
- Temporary shelters provided by governments
- Philippines Red Cross delivered food aid
- 1200 evacuation centres set up for homeless
using an example, describe the LONG-TERM responses to a tropical storm
- Thousands of homes built away from areas at risk of flooding
- Rice farming and fishing industry re-established
- Cyclone shelters built to accommodate evacuated people
list the types of extreme weather that can be experienced in the UK and 2 effects of each
- heavy rain (floods damage homes/force businesses to close)
- strong winds (disrupts transport/ flying debris can injure people)
- hailstorms (destroy crops/damage property)
- heavy snow & ice (slipping causes injuries/ airports close = major economic impacts)
- drought (crop failures/conserving water ie ban on hosepipes)
- thunderstorms (rare deaths/fires that damage property)
- heat waves (pollution builds up in air = death from breathing difficulties/ tourism may beneifit)
give 3 pieces of evidence of weather becoming more extreme in the UK
- extreme temps (dec 2010 coldest winter in 100 years; april 2011 warmest april on record)
- more rain (2013 wettest year recorded; dec 2015 wettest month on record)
- major floods more often (cumbria had serious flood in 2005, 2009, 2015-16)
give an example of one extreme UK weather event and explain what caused it
somerset floods, december 2013/14
- v. flat part of land
- depression across atlantic brought 350mm of rain
- rivers not dredged for 20 years (clogged sediment)
what is the quaternary period
most recent geological time period from 2.6 mill years ago to now
before this time, earths climate was warm & stable
shifted from cold glacial periods (10,000years) to warmer interglacial periods (100,000years)
give three pieces of evidence for climate changing in the quaternary period
- ice cores - longterm(scientist drilled into ice cores & analysed gases trapped showing temp each year - increased rapidly)
- tree rings - longterm(counted tree rings -new ring each year - ring is thicker in warm temp so tells us the climate)
- temp records - shortterm(since 1850s temp recorded using thermometers)
what are the natural factors that can cause climate change
- orbital changes (earth’s orbit around sun changes from perfect circle to ellipse every 96000 years)affects the amount of solar radiation earth gets
- volcanic activity(when eruption occurs, particles reflect sun rays to space so earth cools)
- solar output(suns energy output varies over periods of 11 years. reduced solar output may cause earth to cool in some areas)
what is the greenhouse effect
- when greenhouse gases ie co2/methane absorb outgoing heat so less is lost to space
- too much g.h. gases in atmosphere means too much trapped energy and plant warms up
how can human activities increase the concentration of greenhouse gases in the atmosphere
- burning fossil fuels (when burnt ie through petrol and coal, co2 is released)
- farming (cows produce large amounts of methane when ridding gases from their bodies)
- deforestation (trees remove co2 from atmosphere. when chopped down, stop taking in co2 & also release it when burned)
give three effects of climate change on the environment
- ice caps melt causing habitat loss and rising sea levels
- coral reefs are bleached bc of rising sea temp
- quantity of species (habitats are being destroyed by climate change & species adapted to cetrtain areas with certain climates which are now changing could become extinct)
how might alternative energy production reduce the causes of climate change
- less greenhouse gases produced by burning fossil fuels
define a GEOLOGICAL hazard and give three examples
caused by land and tectonic processes
- volcanoes
- earthquakes
- avalanches
define a METEORLOGICAL hazard and give three examples
caused by weather and climate
- tropical storms
- heatwaves
- climate change
describe the differences between continental and oceanic crust
OCEANIC CRUST - thinner (5-10km) - more dense CONTINENTAL CRUST - thicker (30-50km) - less dense
label the inner structure of the world
inner core, outer core, mantle, crust
how are destructive plate boundaries formed
- plates are moving bc of convection currents
- oceanic crust moves towards continental plate
- oceanic is more dense so subducts under mantle & destroyed
- creates volcanoes & ocean trenches
- two continental plates can collide and be forced upwards & fold creating mountain ranges
how are conservative plate boundaries formed
- plates are moving bc of convection currents
- two plates move sideways past each other (diff direction)/ same direction diff speeds
- causes earthquakes
what are the nature of natural hazards and how do they affect the hazard risk
- type. higher hazard risk for more sudden hazards ie earthquakes - hard to predict
- freq. some occur more than others increasing hazard risk
- magnitude. more severe hazards cause greater effects than less severe ie 9.0 earthquake - 15000 dead; 6.3 earthquake 300 dead
name all four management techniques
monitoring, prediction, protection, planning
describe how tectonic hazards can be monitored
- VCNO. seisometers monitor earth’s movements used as an early warning system
- VCNO. scientists monitor signs that come before volcanic eruption ie escaping gas and tiny earthquakes
describe how tectonic hazards can be predicted
- ERQK. movement of tectonic plates monitored forecasting which areas should prep for earthquake
- VCNO. if well monitored, predicting when it occurs gives ppl time to evactuate and reduces no. of deaths
describe how tectonic hazards can be protected against
ERQK
- buildings designed to withstand earthquakes ie reinforced concrete absorbs earthquakes energy
- buildings strengthened ie pillars wrapped in steel frames so less likely to collapse bc of shaking from earthquake
- automatic gas & electricity shut off switches fitted to prevent fires if earthquake is detected
describe how tectonic hazards can be planned for
- emergency services train for disasters, reducing no. of ppl killed ie practice saving ppl from collapsed building
- emergency supplies ie blankets & food stockpiled so ppl have enough to survive if trapped
- government plan evac. routes getting ppl out of dangerous areas quick preventing injuries from fires/ mudflows
name and describe the features of a tropical storm
- eye of storm has no wind/rain, low pressure
- rain bands surround the eye
describe how tropical storms can be predicted
- data from satellites used to monitor storms. computer models can predict the path of the storm
- prediction give ppl time to protect their homes ie by boarding up windows
describe how tropical storms can be planned for
- emergency services prepare by practicing saving ppl from flooded areas reducing no. of ppl killed
- governments plan evac. routes to get ppl away from storms quickly
describe how tropical storms can be protected against
- buildings designed to withstand tropical storms ie putting building on stilt away from floodwater
- flood defences built along rivers and coats ie sea walls, reducing buildings detroyed and no. of ppl killed, injured & homeless
describe how extreme weather in the UK can be predicted
- prediction (warning systems ie Met office give ppl time to prepare)
describe how extreme weather in the UK can be protected against
-protection (local authorities prepare before it happens ie stock up on grit/salt supplies)
describe how extreme weather in the UK can be planned for
- planning (local councils know how to prepare ie close schools when weather is too dangerous)
give three effects of climate change on people
- deaths due to heat increased
- low crop yields could increase malnutrition & death from starvation in hotter countries
- some places struggle supplying enough water to residents leading to political tensions
define mitigation
taking action to reduce the causes of climate change
trying to prevent the problem from happening
define adaptation
adjusting/ responding to the effects of climate change
coping with the negative effects of the problem
describe three mitigation strategies
- carbon capture (capturing CO2 & transporting it deep underground - reduces emissions from fossil fuels)
- planting trees (increases the amount of CO2 absorbed through photosynthesis)
- international agreements (countries set targets for the reduction of CO2 emissions in their country ie Kyoto protocol UK agreed 12.5% reduction)
describe three adaptation strategies
- agricultural change(change crop type grown suitable for new climate/create new crop varieties resistant to extreme weather ie S.A drought resistant millet)
- managing water supply (water meters installed-ppl dont use as much water/ rainwater collected)
- coping with rising sea levels (physical defences ie flood barrier in london/ houses built on earth embankments in bangladesh)
describe how a place’s capacity to cope with natural hazards affect the hazard risk
if a place has enough money to protect themselves ie flood defences and repair costs) they can cope with natural hazard and the hazard risk is lower
describe how a place’s vulnerability to natural hazards affect the hazard risk
the more people in areas exposed to natural hazards, the greater the probability they will be affected by it, the higher the hazard risk
describe three secondary effects of an earthquake in a POORER part of the world
- avalanche on mt everest killed 19 people
- houses destroyed causing food shortages/no income
- earthquake happened before monsoon season = more destruction
describe three secondary effects of an earthquake in a RICHER part of the world
- aftershocks caused landslides which damaged housing
- central businesses cordoned off (bad for local economy)
- decreased umber of uni students
describe three short term responses to an earthquake in a POORER part of the world
- $130 million raised by UK DEC (emergency aid)
- temp shelters set up for 200,000 homeless
describe three short term responses to an earthquake in a RICHER part of the world
- 40,000 tents for the homeless
- italian red cross searching for survivors within hours
- mortgages and bills for gas/ electricity suspended
describe three long term responses to an earthquake in a RICHER part of the world
- residents didnt have to pay taxes in 2010
- students exempt from uni fees for 3 years/ given free transport
- procession took place remembering those who died
describe three long term responses to an earthquake in a POORER part of the world
- heritage sites reopened to encourage more tourism
- 8 months after a reported $270 million of aid was donated
- 23 areas need rebuilding after a post disaster needs assessment was carried out
give an example of a tropical storm (location, date)
typhoon haiyan
Tacloban, Philippines
2nd october 2013
using an example, give the primary effects of an extreme weather event in UK (4)
- 600 houses flood, in polluted water for 6 weeks
- cost £10 million
- 14,000 ha of farmland underwater for 4 weeks
using an example, give immediate responses of an extreme weather event in UK (3)
- local volunteers gave their support
- villagers used boats to travel instead of cars
- debris cleared
using an example, give long term responses of an extreme weather event in UK (3)
- 8km of river tone & river parratt dredged (increased capacity of river)
- road level raised to maintain communication
- vulnerable communities have flood defences
using an example, give the secondary effects of an extreme weather event in UK
- 1000 livestock had to be evacuated from 16 farms
- power cut off
- residents in temp accommodation for months
how are constructive plate boundaries formed
- plates are moving bc of convection currents
- two plates move away from each other
- magma rises from mantle to fill gap & cools creating new crust
- creates volcanoes
what is magma
molten rock
what is lava
molten rock that reaches earths surface
how does global atmospheric circulation lead to high and low pressure belts
- warm air rises (air rises at the equator)
- at areas of low pressure, winds on the ground move towards the low pressure areas
- this fills the space left by the rising air
how does a tropical storm develop
- sun warms sea to 27* causing evaporation
- the moist warm air rises causing low pressure conditions
- as air rises, cools & condenses & draws in more moisture from sea causing strong winds
- Coriolis effect causes air to spin upwards. some cooled air sinks down creating a calm central eye
- as air rises & condenses forms large cumulonimbus clouds causing heavy rainfall
- air rushes in from high pressure areas outside storm to lower pressure areas at centre of storm creating winds
