hazards Flashcards
hydrometeorological vs geological hazards
hydro : caused by weather or water
geo : movement in crust
why might someone live in hazardous areas
they enjoy the area and take the risk
volcanoes provide geothermal power e.g in iceland 27% of electricity comes from geothermal power
tourism benefits e.g mount etna in italy
no knowledge
no other choice
fertile soil
4 factors that affect the risk of hazards
urbanisation
poverty
farming
climate change
how are earthquakes distributed
on plate boundaries
how do conservative plate boundaries cause earthquakes and an example
• friction causes consistent, minor earthquakes
• become “locked” by objects in ground
• pressure builds and convection currents continue to apply force
• pressure releases, seismic waves sent through crust
san andreas fault
how do constructive plate boundaries cause hazards with example
• magma rises to fill gap between plates as lava
• lava forms basalt
• shield volcanoes form, huges ridges
• magmas continues to crack through
mid atlantic ridge
how do destructive plate boundaries cause hazards with example
• cont and ocean plate converge
• ocean plate is denser and heavier so is subducted into oceanic trench
• friction melts plate to magma
• magma less dense than solid rock so rises through cont plate
nazca plate & south american plate
how can we predict earthquakes and disadvantage
seisometers to monitor tremors and find out where they will happen
difficult to find out when
three ways we improve buildings to keep safe from earthquakes
• rubber shock absorbers in foundation
• steel frames that sway
• open areas outside for evacuation
how do we prepare for earthquakes
earthquake drills to reduce affect and increase survival
stockpile supplies
what conditions are needed to form a tropical storm
sea at least 27°
coriolis effect
unstable conditions in equitorial regions
light wind shear
6 steps on how tropical storms form
ECEPL
• conditions required occur
• rapid rates of evaporation transfer huge quantities of warm water vapour rapidly into air
• cool and condenses into towering thunderstorm clouds. several join to form tropical storm
• eye develops where air descends rapidly. eye wall forms around and is where strongest winds and heaviest rain are felt
• prevailing winds carry storm across ocean and the storm gathers more strength
• land slows and weakens storm due to friction
where are tropical storms called hurricanes
usa and caribbean
where do they call tropical storms typhoons
japan and philippines
where do they call tropical storms cyclones
se asia, aus and africa
when was cyclone idai
14-15 march 2019
when was cyclone idai
14-15 march 2019
where did cyclone idai make landfall and what countries were affected
landfall: beira in mozambique
affected: mozam, zimb, malaw, madag
what was cylcone idai’s:
category
wind speed
storm surge
rainfall
catergory: 2
wind speed: 180 km/h
storm surge: 4m
rainfall: 600mm
brief description of cyclone idai’s track
formed: near west coast of madagascar in mozambique channel
travelled southwest
landfall in beira
turn north west into zimbabwe
6 primary impacts
initial deaths was 1300
90% beira destroyed
3 000 000 affected
17 hospitals destroyed
power lost and roads gone (flood)
agricultural fields destroyed in malawi
how can you track tropical storms
satellite photography
one proof of heat in uk becoming extreme
2003 in kent - record high. 2000+ died, railways buckled and roads melted
2019 in cambridge - record beaten
proof of extreme weather - flood
2013 - 14 , wettest winter in 250 years
4 methods of measuring climate change
ice cores
shrinking glaciers
rising sea level
seasonal changes
how can you use ice cores to measure temp change and how accurate
drill deep into ice, as it traps carbon molecules.
more molecules = warmer
very accurate
how do you measure temperature change with shrinking glaciers and how effective
satellite images to record changes in size. thinned by 65% since 1975
accurate
how can sea level show temp change and how accurate
melting glaciers and thermal expansion rises sea level
rose 3.2 mm per year 1993-2015
accurate
how can we use seasonal changes to measure temperature change and how accurate
track animal migration, blossoming and weather
advancing by 2 days per year
not as convincing, hard to track
5 natural causes of climate change
precession
axial tilt
eccentricity
solar activity / sun spots
volcanic activity
describe precession
natural wobble
complete cycle takes 26000 years
northern norway experiences long days and nights in parts of year
describe eccentricity
uneven path of earth rotation
not fixed, changes from circular to mildly elliptical
every 100 000 years
describe axial tilt
angle of tilt changes between two extremes, 21.5 and 24.5
every 41000 years
more angled toward the sun, nothern hemisphere warms, where most population is
describe how volcanic activity affects climate change
blasts huge quantities of ash, gas and liquids into atmosphere
blocks sun, short term reduction in surface temps, “volcanic winter”
what is the green house effect
co2 and methane absorb and trap heat
what is the enhanced greenhouse effect
acceleration of natural climate change by humans
how does deforestation cause climate change
accounts for 20% of emissions.
releases carbon stored during photosynthesis
three human factors of climate change
fossil fuels
deforestation
agriculture
how does agriculture contribute to greenhouse gases
• accounts for 30% emissions
livestock release methane as burps
• anaerobic decomposition in paddy rice cultivation accounts for up to 20% total methane human emissions
• 75% all nitrous oxide comes from manure and fertilisers
whats the word for when you want to say something was man made
anthropogenic
what is mitigation
stop climate change from happening
what is adaptation
adjustments to our lives and changes take place
three mitigation strategies
carbon capture
planting trees
international agreements
how does carbon capture work
• capture co2 from burning fossil fuels
• co2 is then compressed & piped
• then injected underground for long term storage in geological reservoirs
how does planting trees effective mitigation
carbon sink
• remove co2 through photosynthesis
• release moisture, cloud reduces incoming solar radiation
how do international agreements help mitigation
legally binding “paris agreement” 2016
limit temperature increase to 15° above pre industrial levels
how does alternative energy sources promote mitigation
hep, wind, solar, nuclear, tide
low carbon alternatives
by 2030, uk aims to get 65% energy from renewable energy stores
two ways we can adapt to climate change
change in agricultural systems
managing water supply
how can we change agricultural systems to adapt to climate change
• cope with extreme weathers
• storing and efficiently irrigating water
• drought resistant crops
