Transcript Y7 U2A Hurricanes PP Sept 21 - fhouses

This is the next unit
Unit 2
Weather and its effects
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The next 5 weeks
• Week 1: What is a hurricane? What is it
like for people in an MEDC?
• Week 2: What was cyclone? What is like
for people in an LEDC?
• Week 3: British weather systems: What is
an anticyclone like?
• Week 4: Why was our summer so wet?
• Week 5: Why is El Nino so important?
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What is a hurricane?
• It is a weather system that forms out over the
ocean, and develops into a whirling, very windy
storm with heavy rain
How are they different from typhoons and
cyclones?
• They aren’t – it depends where you are in the
world. If you are in the Atlantic, they are called
hurricanes, if you are in the Pacific Ocean they are
called typhoons and if you are in the Indian Ocean
they are called Cyclones.
• Did you know that in Australia they are called willywillies?
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Here is a hurricane
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Now shut your eyes
Try and draw a picture in your head
Because when I have finished I want
you to make an annotated sketch or
several of them if you like about how
the hurricane forms
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• Hurricanes all start over the sea where, for reasons that we
do not fully understand, a patch of ocean has a surface
temperature of more than 260C. The hot air rises taking a lot
of water vapour with it. As the water vapour rises up it cools
to form big cumulus clouds. This creates low pressure at
sea level. Wherever you have low pressure, air with higher
pressure tends to move in to replace it.
• The winds that travel around the Earth (called the Trade
Winds) at this point are pulled in to fill the gap left by the
rising air. But due to the turning effect of the earth, air does
not move straight into a low pressure zone but whirls in
around and towards it – just like the water going down the
plug hole – for the same reason. Remember the world is
turning at about 1700 km an hour!
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• We have the hot air rising, the air coming in from outside
and coming under the cloud in a spin, picking up more
water vapour and spiralling upwards as it warms. This has 2
effects; the first is that the storm clouds begin to be pulled
into a spin by the incoming wind. The second effect is that
the spinning storm is pulled outward – leaving a low
pressure funnel at the centre. Now way up high there is cold
air which is under higher pressure so this is sinks down into
the centre – at the bottom this begins to warm and gets
pulled in to the warm spinning stormy mass, and so more
cold air follows in after it. As everything is spinning faster
and faster the storm begins to drift sideways because of the
trade winds.
• Not only that but this huge bundle of energy depresses the
sea level under it, so there is a backup ridge of water all
around it – this gives rise to surges both before and after
the hurricane has passed.
• So the hurricane brings surges and high winds and heavy
rain all together! This why they cause so many problems to
the countries they cross.
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This gives a really neat intro
See if this is like your picture
http://www.curriculumbits.com/
prodimages/details/geography/
geo0008.html
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And this was Gustav that did less damage
than feared!
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Hard Times for ‘The Big Easy’
(a nick name for New Orleans)
Just eight months after the Asian tsunami, the world is
again humbled by the power of nature. This event,
however, makes us ask new questions ……. about
human nature and American society.
VV ’05
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The Location of New Orleans
New Orleans is in the state of Louisiana. It is located on the delta of the
Mississippi River about 170km from its mouth on the Gulf of Mexico
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Lake
Pontchartrin
Mississippi
River
Gulf of
Mexico
Mississippi Delta
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Mississippi River
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New Orleans : some facts
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A city of 470,000 people (67% Afro American)
Founded by the French in 1718
Expanded by the Spaniards
Bought by the USA for $15 million in 1803
A lively port and industrial city
Home of jazz and cajun and creole cooking
Hosts an annual mardi gras carnival
Attracts hundreds of thousands of tourists
every year
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But in the aftermath of Hurricane Katrina which swept by on
29 August 2005, the levées broke and the city was
flooded………
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Two days before, the people of New Orleans had watched
and waited as Hurricane Katrina approached…….
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People who
had transport
fled the city
Shop keepers
boarded up
their windows
Volunteers helped
to fill sandbags
And those
without the
means to
drive out had
to stay
behind
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Downtown
New Orleans
at the height
of the storm
on 29 August
The eye of the
hurricane
passed to the
east of the city
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After the
storm…..
It seemed New Orleans had got off
more lightly than expected…
until the levées broke and water
flooded into the city…………
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Within 24 hours 80% of the city was under water
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Affluent housing sinking beneath the rising tide
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Public transport is out of action
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Many people drown – Government
estimates warn of several thousand dead
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One hundred
thousand people
who were not able to
leave the city….
…are trapped in
their homes.
Most of these had simply
been too poor to flee
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The water is
polluted with
sewage and oil
….but people are
forced into it in
order to survive
Food and drinking water becomes scarce within
hours and is only flown in two days later
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Hospitals evacuate patients by boat
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As the story unfolds on TV screens
across the globe, the American
government seems slow to
respond to the scale of the disaster
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The police struggle to contain a rising tide of lawlessness
A slow evacuation
begins
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Some emergency relief
begins to arrive in the
city
But with no means
of evacuation,
conditions
continue to
deteriorate for
most of those still
trapped in the city
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23,000 people take refuge in the New Orleans Superbowl
without running water and adequate sanitation. Reports
likened conditions to ‘a Third World refugee camp’
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Four days after the storm US President George
Bush flies over the city to view the catastrophe
first hand …….
“The enormity of the task requires more resources”
“In America we do not abandon our fellow citizens in
their hour of need”
“Where our response is not working we will make it right.
Where our response is working, we will duplicate it”
“The main priority is to restore and maintain law and
order and assist in recovery and evacuation.”
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More helicopters
are drafted in to
help with the
evacuation of the
city
Convoys of
buses evacuate
people from the
Convention
centre in New
Orleans
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Six days after the
storm, the city is
almost empty
The waters are
slowly receding…
And the grim task
of searching
buildings must
begin.
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“The first few days were a
natural disaster, the last four
days were a man-made
disaster”
Phillip Holt, 51
New Orleans evacuee
Photograph credits – ‘Der Spiegel’
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A couple of words
• Impacts are forceful consequences or
strong effects of something
– These impacts may economic (about money)
or human (about people)
• Responses are reactions ,what people do
as a result of a situation
– The responses may be short term (actions
that taken within days of the event) or long
term (taken over months or years afterwards)
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Impacts – human, economic, both or
neither?
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1,500 deaths occurred in the states of Louisiana, Mississippi and Florida
The impacts of Katrina is thought to have cost about $300 billion
Thousands of homes and businesses were destroyed
Thousands of jobs have been lost and millions of dollars in lost tax incomes
to the affected states and USA federal government.
Agricultural production was damaged by tornadoes and flooding. Cotton and
sugar-cane crops were flattened.
Three million people were left without electricity for over a week after the
Hurricane struck.
Tourism centres were badly affected, probably reducing income for several
years.
There have been adverse impacts on the oil and gas industry. A significant
part of the USA oil refining capacity was disrupted after the storm due to
flooded refineries and broken pipelines, and several oil rigs in the Gulf were
damaged.
Evacuees have not returned to the affected areas, producing a shortage of
workers for businesses that reopened months after the hurricane struck.
Major highways were disrupted and some major road bridges were
destroyed.
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Responses- long term, short term or
neither?
• Many of those who left, went to other towns and the migration has
become permanent as people have settled in other parts of the USA, for
instance when peoples’ houses and businesses were permanently
destroyed.
• Around 20,000 people in New Orleans sheltered in the Superdome
football stadium when warned the hurricane was about to strike.
• However, the living conditions in the Superdome soon deteriorated. It
became hot and stuffy, toilets were broken and there were no washing
facilities.
• Eventually a convoy of 475 buses transported many of these people to
the Astrodome stadium in nearby Houston, Texas.
• Lawlessness broke out and emergency services could not operate
properly.
• Criminal gangs roamed the streets, looting homes and businesses and
committing other crimes. Army and police had to try with difficulty to
maintain order when living conditions became intolerable and there was
competition for food and drink.
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Responses- long term, short term or
neither?
• Unfortunately, bodies of people who died in the August
2005 were still being discovered late into 2005.
• One of the first challenges in the aftermath of the flooding
was to repair the broken levees. Vast quantities of
materials, such as sandbags, were airlifted in by the army
and air force and the levees were eventually repaired and
strengthened.
• But the water took many months to dry out and much
rebuilding had to wait.
• Although the USA is one of the wealthiest developed
countries in the world, it highlighted that when a disaster is
large enough, even very developed countries struggle to
cope with natural disasters, particularly the poorest people.
• But many Americans felt their government could have done
a whole lot better – and certainly much more quickly.
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