Natural hazards and climate change Flashcards
Why does it rain?
air rises because it’s hot, there is an obstacle in the way (mountain) or because cold air forces it upwards. It then cools in the atmosphere. This creates condensation and clouds. Eventually, the clouds are too dense and rain falls
What does low pressure systems bring?
Clouds and rainfall, as hot air rises and cools
What does high pressure systems bring?
Dry, dense air as cold air sinks. This either creates very hot days or very cold days, with no clouds and dry conditions.
Wind blows out of high pressure systems
Why is it hot and wet in the rainforests?
Around the equator, the sun is the most concentrated, so the solar heat makes the sea hotter. The oceans evaporate, creating a low pressure system and creating lots of rain.
What is the Coriolis effect?
The wind moves in spirals as the earth is constantly spinning
What are the pressure systems called across the globe?
Polar highs - 90*
Sub polar low - 60*
Sub tropical high - 30*
Equatorial low - 0*
What are the wind cells across the globe?
0* - 30* = Hadley cell
30* - 60* = Ferrel cell
60* - 90* = Polar cell
What way are the winds deflected in the north and south?
The anti-clockwise rotation in the northern hemisphere deflects winds to the right
The clockwise rotation in the Southern Hemisphere deflects the winds to the left.
What temperature does the ocean need to be at to create a storm?
27 degrees Celsius
When does water vapour condense?
1 degree Celsius per 100m
What’s the scale to measure tropical storms?
The saffir-Simpson scale
Where did tropical storm Haiyan hit?
The Philippines, coming into south east Asia
How many people did Haiyan kill?
6,340
Why was the storm in Haiyan so devastating?
The Philippines are LICs and they didn’t predict the storm surge, so people were caught off guard when they hid in basements.
What is the other names for High and low pressure systems?
High pressure - anticyclone
Low pressure - depression
How did the beast from the east form?
Snowstorm from Russia met storm Emma from Ireland over Britain
What were the weather stats of the beast of the east?
20 inch snow 160mph winds in Europe (top speed) -12 degrees Celsius (lowest temp) Blizzards Floods 40cm higher than expected in Cornwall
How are storms formed?
The sun heats up the ocean to over 27 degrees
This causes moist air to rise, creating low pressure at the centre of the storm
This air cools as it rises, at 1 degree per 100m, this causes condensation and clouds to form
Some cooled air sinks back down
Air rushes from high pressure areas outside of the storm to lower pressure areas at the centre of the storm, creating winds
It spins because of the earths rotation
When it reaches land, the source of power fades so it dies
When was Beast from the east?
22nd Feb 2018 - 4th March
Primary effects of beast from the east?
Blizzards
20 inch snow
Floods of 40cm higher in Cornwall
160mph wind in Europe
-12 degrees as the lowest temperature
14 deaths in U.K.
Short term responses of beast from the beast?
Red alert issued
Transport stopped
Firefighters come to help
People stocked up on food
4x4 drivers brought supplies around
When was Haiyan?
8th November 2013
How many homeless people in Haiyan?
Over 4,000,000 homes destroyed
How much money lost in Haiyan?
$20 billion cost
$5. 8 billion for rebuilding
Immediate responses in Haiyan?
1,600 evac centres set up
Makeshift rafts (out of mattresses) were made to get across the storm surge
In first 10 days England delivered 2,000 tonnes of aid
Primary effects in Haiyan?
95% of trees uprooted
Flood water 20ft deep
Boats were destroyed - leaving them stranded
Secondary effects in Haiyan?
Looting - aid was really slow
Stagnant water attracted mosquitos, spreading malaria
Phone coverage was lost
Shocked into birth- lots of pregnancies
Roads were blocked by debris
6 million lost their jobs
Long term responses in Haiyan?
Fish and trees were destroyed, leading to decrease in money
Oxfam says ‘3-5 years recovery’
What caused the earthquake in Japan?
It was a megathrust so the pacific and Eurasian plate collided in the ocean at a shallow focus and a plate was pushed up, sending a tsunami.
When did the earthquake in Japan happen?
11th March 2011
What was the Japan earthquake on the Richter scale?
A 9
How many people dead in the Japan earthquake?
15,853
What were the primary effects of the earthquake in Japan?
Some shuddering and 4 trains were derailed but protections mostly held and everybody was generally okay
What caused the most damage in Japan?
The tsunami
How much damage did it cost Japan?
$300 billion
How many homeless in Japan’s earthquake?
Over 300,000
What happens to the reactor in Fukushima?
Water seeped in, damaging the electrics and it had a meltdown. They shut the nuclear power stations off to prevent explosion, but that caused major blackouts
How many countries came to japan’s aid?
116
How many were evacuated due to Fukushima’s nuclear plant?
140,000
How many reactors were taken offline in Fukushima?
55
What were some long term responses in Japan’s earthquake?
Companies left Japan for economical reasons Took a month to reopen ports 6 months for railways to be rebuilt A year for homes to be rebuilt Redesigning sea defences
Why didn’t the sea defences work in Japan?
The Waves was too high
What is a natural hazard and a natural disaster?
Natural hazard is a natural process that could cause death or destruction to humans
A natural disaster is a hazard that has actually happened
What are geological hazards and meteorological hazards?
Geological - caused by land and tectonics (earthquakes and volcanoes
Meteorological - caused by weather events (hurricanes)
Why would HIC’s be less affected by natural disasters?
They can afford to repair or have defences, limiting the damage made or quickly building them back.
They can afford to predict when one is coming and evacuate
What’s the difference between oceanic and continental plates?
Continental is thicker and less dense
Oceanic is thinner and more dense
What happens when two continental plates meet each other?
They create fold mountains
What happens when two plates are moving away from each other?
This is a constructive plate boundary, causing magma to rise from the gap to cool and fill it creating new crust. This can cause many underwater volcanoes as them magma rises to make a volcano from the gap.
What happens in a destructive plate margin?
The oceanic crust subducts under the continental and gets destroyed by the magma. Pressure is built up due to the plate friction and the magma rises, creating a vent up into a volcano. When the pressure releases, the volcano erupts.
What are conservative plate margins?
When two plates are moving side by side. Crust isn’t created or destroyed.
This could cause an earthquake though, as the rubbing past each other creates friction and then releases
What are features of a volcano erupting?
Lava
Gases (sulphur and co2)
Some volcanoes emit ash - can form pyroclastic flows
Magma boulders
What is the epicentre of an earthquake?
The point on the earth’s surface straight above the focus
What’s the focus of an earthquake?
The point of origin
Why do people live near volcanoes?
They might not be able to afford to move Fertile soil Low chance it will erupt in their lifetime Tourists Feel safe with defences and planning
What can prevent or help plan for earthquakes?
Seismometers and laser monitors can be used as early warning systems
They can predict an earthquake by measuring the tectonic plates
Buildings can have reinforced concrete that absorb shock or have steel frames. Automatic shut off switches turn of gas and electricity to stop fires
Evacuation routes are planned
What can prevent or help plan for volcanoes?
Volcanoes can monitor tell tale signs that one will erupt (escaping gas, changes in shape)
Trenches used to divert lava, buildings can be reinforced to not collapse against the ash
Practice evacuation
How does air move in global wind cells?
The sun warms the equator, making hot air rise. This creates a low pressure belt
As the air rises it cools and moves away from the equator
30 degrees north and south, it sinks and cools creating a high pressure belt
At the ground surface it either goes back to the equator (as the trade winds) or towards the poles (as westerlies)
What were the most affected places in Haiyan’s storm?
Tacloban and Cebu in the centre of the Philippines with up to 280mm of rain and winds reaching a maximum of 314km/hour
What may climate change affect about tropical storms?
The distribution- forming more north and south
The frequency
The intensity
Why would the frequency of storms change due to climate change?
The oceans will stay at 27 degrees and higher for longer as the earth is hotter
Why would the distribution of storms change due to climate change?
As the earth is hotter, more of the oceans would be at 27 degrees, meaning there will be more storms in various places
Why would the intensity of a storm change due to climate change?
Hotter seas mean more evaporation and increased cloud formation so more energy is released. This could mean storms become more powerful
What are ways to prepare for a storm, limiting its effects?
Monitored using radar or satellite
Predicting where it will travel and evacuating
Drills and evacuations practiced as well as emergency services rehearsed
Buildings put on stilts and reinforced to defend against flooding and wind
Flood defences in the rivers and oceans
What management strategies are used to reduce flood risk?
Warning systems
Using sandbags and floor boards
Building tidal barrages
Widening channels and rivers
What is ‘climate change’?
Any significant change in the earth’s climate over a long period
What are natural factors of global warming?
Orbital changes such as the tilt and wobble, making the earth take in more energy
Volcanic activity as the ash acts a greenhouse gas
Solar output, as the sun gets hotter and cooler
What are human factors of global warming?
Burning fossil fuels
Cement production as carbon is produced
Farming as cows produce methane
Deforestation as it removes carbon traps
What effects do climate change have on the environment?
Warmer temperatures cause glaciers and ice to melt, this causes sea levels to rise and polar animals to die out
Low lying coastal areas will be flooded
Coral reefs are being bleached due to the rising temperature of the ocean, making algae die
Precipitation patterns
What effects do climate change have on humans?
Death due to heat has increased
Flooding of coastal areas kills, leading to overpopulation in other places
Droughts
Change in rainfall patterns lead to a lack of water
Crops that die, but also crops in higher latitudes do well in the warmth
Crops dying could increase malnutrition and death
More extreme weathers resulting in natural disasters
What does mitigation mean?
A way to prevent something from happening
What does adaptation mean?
A way to adjust to what has happened
What mitigation strategies have taken place to stop climate change?
Capturing CO2 and storing it underground
Replacing fossil fuels with renewable energy
The Paris Agreement reduces greenhouse gases production by 40% for each country
What adaptation strategies have done to adapt to climate change?
Planting new crops that will thrive in new conditions or using biotechnology to grow plants indoors
Water meters and storage of water to conserve water used due to rainfall patterns
Better flood warnings and flood defences
What are the layers of the earth?
Crust
Mantle
Outer core
Inner core
What causes the tectonic plates to move?
Heat and magma from the core create currents that make the plates above move very slowly
What is the crust made from?
Solid rock from 5 to 50 km deep
What is the mantle made from?
Molten magma, behaving like a liquid with slow moving currents
What is the outer core made from?
Liquid magma
What is the inner core made from?
Solid molten magma and iron
How often do tectonic plates move?
Around 2.5cm a year
What are the four main plates
South American
Eurasian
Australian
Cocos
What was the supercontinent called?
Pangea
What was Wegner’s two pieces of evidence?
The continents fit together
There were the same dinosaur fossils on different continents
What are the three types of plate movements?
Destructive
Constructive
Conservative
What does natural increase mean?
Where there are more births than deaths, resulting in population growth
What does net migration mean?
When more people are moving in than moving out. Some migration is forced and LICs mostly move rural to urban
How to read contour or isoline lines on a map
If the place you’re interested in is on a line, read the line
If it’s between two lines, estimate the value
