Transcript Tropical Cyclones - Western Springs College .::. Welcome

Tropical Cyclones
Heta and Katrina
Focus Statements.





natural and cultural characteristics (features) of the
environments that make them vulnerable to the extreme
natural event(s)
natural processes that operate to produce the extreme
natural event(s)
effects of the extreme natural event(s) on the natural
environments
effects of the extreme natural event(s) on the cultural
environments
how different groups of people have responded to the
effects of the extreme natural event(s).
Weather Map reading and air pressure
(n)





Air pressure always moves from high to low
pressure.
When an area has low pressure in the middle and
close isobars it shows that it is extremely windy.
When an area has high pressure and the isobars
are far apart it means that it is probably warm and
still.
Low pressure systems have rising air that is being
heated therefore it is light.
High pressure systems have sinking air that is
cooling therefore is more dense.
Weather

processes\Weather maps presentation.pptx
Tropical Cyclones!!!





Tropical Cyclones are areas of extreme low
pressure.
This low pressure creates violent storms that are
characterised by winds over 100km/h and heavy
rainfall.
They have caused the loss of life on a number of
occasions due to there intensity.
In parts of Australia they are called Willy Willies,
Asia they are called Typhoons, Northern
Hemisphere they are called Hurricanes.
So lets look at what creates them.
Climatic Processes




Heating of the sun at the equator causes air to rise creating
an area of extreme low pressure near the earths surface.
The air that is heated by the sun rises into the upper
atmosphere, where it cools and condenses (becomes
heavier), descends at latitudes 25 degrees n+s. (Remember
sinking air is low pressure)
As high pressure always moves towards low winds are
created. These are known as the trade winds.
These winds converge 5 degrees North and south in a area
known as the ITCZ.
Climatic Conditions (c) Hadley cell.
The Trade winds: Where the trade winds meet
rainstorms occur (frontal rainfall) They meet at the
Inter Tropical Convergence Zone (ITCZ)
How a TC forms



5 Step diagram
Copy in Processes above and on earth
diagram pg 109.
Summarise into 3 step diagram (exam)
Tropical Cyclones





TC’s in the Southern Hemisphere move in a south-easterly
due to the trade winds and the spinning effect of the tropical
cyclone.
Once the cyclone has reached the eye there is a period of
calm followed by winds in the opposite direction these repeat
the process of the earlier winds.
When a cyclone cannot produce enough latent heat to feed
itself or it reaches a large land mass it looses strength and
becomes a depression again.
Questions: Pg 108.
processes\CYCLONE PROCESSES cloze.docx
Physical Changes






How do tropical cyclones affect the land?
Violent waves
Storm Surges
Storm Waves
Heavy rainfall.
Read pages 114,118 answers questions.
Physical Changes




Brainstorm what are the earth altering affects of
cyclones? Brainstorm how these conditions alter
the land. (Think if somehow a cyclone formed
over Dunedin.
I.e. wind can break off branches.
Notes
natural environment\Tropical Cyclones effect on
natural environment brief notes.doc
Anatomy of a tropical cyclone
Birds eye view
High Islands

Tropical cyclones affect high Islands in a
different way to low Islands. High Islands
are usually volcanic mountainous Islands
like those of Hawaii. Due to their altitude
they are more prone to the effects of wind,
and erosion often in the form of landslides.
High Island
Low Island

Low Islands are also called coral atolls and
they literally are very low to the ocean.
Some don’t get more than 5 metres above
sea level. These islands are more prone to
flooding, either from rain, storm surges or
high seas.
Low Island
Drawing the islands

Draw each island and the effects it feels
from page 112. Each island should be
drawn ½ page in size.
Cultural Environment





Tropical Cyclones affect the social environment in
a large number of ways.
These affects are either economic or Social.
Economic is referring to how the affect the flow of
money in the area they strike.
Social is how the affect the way people move and
interact in their daily life.
The affects of Tropical Cyclones are usually
Negative i.e. loss of life however there are also
times when they have benefits for people.
Activity




Using the template write the following effects of
TC’s into the top boxes.
High seas, storm surges, heavy rain, Strong
winds.
In the second row of boxes explain what problems
these things could create.
In the 3rd column explain how these problems
could affect the economy. Do it Neatly!!!!!!
Activity




Using these words create another diagram:
High seas, Storm surge, heavy rain, strong
winds.
Explain what these conditions lead to.’
Explain how these affect people’s day to day
living.
Preparing for before, during and after
a TC.



For the people who live in areas where
cyclones form (Pacific Islands) TC’s are
inevitable.
People in these areas have made and are
making adjustments to their lives so TC’s
don’t affect them as much in the future.
These adjustments can occur either before
during or after the TC has struck.
Before during and after.



Groups of 3-4 diagram: How could we
prepare for a tropical cyclone.
Create notes using pages 120-123 put
each paragraph into your own words. This
is also homework.
Do activities page 123.
NIUE
NIUE







Title Niue and Tropical Cyclone Heta!
Read through Pasifika book answer the following
question including Question within Answer:
What kind of Island is Niue?
How high are the cliffs around the ocean?
What height does Niue dip to in the middle?
Why would this potentially be hazardous for
cyclones?
What is the rock that makes up the Island of
Niue?
Cyclone Heta


Cyclone Heta was a powerful category 5
cyclone that caused massive damages to
Tonga, Niue, and American Samoa in late
December 2003.
Heta ended up causing 207 million dollars
worth of damage to the pacific Islands it
came in contact with.
Heta: (Formation)





Ocean in the pacific was heated to 27 degrees C.
Heta formed January 1 2004 over a deserted part
of pacific ocean just south of Tokelau. This is the
cyclone season due to suns position.
Heta formed at 10 degrees south of the equator
where trade winds are strong.
Heta air pressure = 915hpa
Winds of over 250 km/h
Heta
Heta Hits Niue


Cyclone Heta travelled south east towards
the small atoll of Niue which would feel the
full force.
Using pages 111-113 construct a timeline of
the events for Cyclone Heta.
Heta hits the natural environment (n)



Niue is a small coral atoll of only 250 square km
located 19 degrees south of the equator.
Niue’s highest point if only 68 metres above sea
level.
These factors combined with the 7 metre storm
surge and the 10 metre waves and 300km/h gusts
of wind meant the damage that was done to Niue
and its capital Alofi was extensive.
The damage







Mass flooding
Buildings and buildings roofs being ripped clean
off.
Coral Deposition from reefs 200m below sea level
Salinisation of fresh water supply
Eroding of banks in the north
Mass vegetation stripping from wind and..
Vegetation being stripped from salt spray.
Dimitry Viliamu’s home
Hotel Niue
Coastal township
Fuel Tank
Claytons bar
Hotel Niue
Huanaki culture centre
Hotel Niue
Niue’s Telecom Dish
Niue adventure and Alofi Rentals
Dive Niue
Carmen Fuinui’s home.
Heta affects the natural landscape






Small coral atoll of only 256 square km.
Heta flooded Niue with 4-7m storm surges and 10 metre
waves that washed 100m inland
Coral was removed from the reef and deposited onto
the beach front by the storm surge.
Storm surge eroded the beach front and created steep
banks. It also demolished substantial amounts of
vegetation on its way.
Coral reef was removed from 200m below sea level.
Salt water contaminated fresh water.
Continued





Wind gusts up to 300 km/h caused severe
damage
80% of the trees had their foliage ripped off.
Coconut trees were uprooted.
Some of the foliage that remained was killed by
the salt spray that was whipped up by the wind
and killed vegetation
The huge period of drought after the cyclone
provided the island with a large fire risk
Social effects of Cyclone Heta








One life lost.
Hundreds of homes destroyed.
200 residents made homeless – 10% of
population.
The hospital was basically destroyed.
Fresh water supplies contaminated with salt water
Sewage pumps no longer worked.
No running water available.
People traumatised and needing counselling.
Economic Effects






Clean-up costs $20 million (emergency response and start of
recovery)
Estimated cost of rebuilding is over $25 million. Hotel Niue
destroyed.
$240,000 loss of crops, i.e. coconut and fruit plantations.
Loss of tourism income from expected 2700 tourists (based
on 2003 statistics)
Satellite dishes and phone systems knocked out.
Bulk fuel storage facility ruined and all fuel leaked into the
sea.
Activity


cultural environment\economic social
effects heta.doc
Match them into the correct category:
Social or Economic.
Preparing for a Tropical Cyclone


If a TC was going to hit NZ.. Especially
Dunedin what kind of things would you do
to prepare?
Answer this as a think pair share activity…
Preparing for Tropical Cyclones





Boats were secured to the wharfs and some were
taken off the ocean and put inland.
Families began watching the Ocean.
Important clothes were packed away in case
people were homeless for an extended period of
time.
Wooden shutters were put over windows to try
and minimise the effects of strong winds.
Cars were filled with petrol and parked away so
people didn’t steal gas.
Preparing for




Television aerials were removed and loose
items were secured.
Emergency meeting places were agreed in
carmen’s case it was the High Commission
building.
Every available water container was filled.
First aid kits were gathered
Response to Heta


Read pasifika book (Carmens story)
Document how people responded
Response to Heta












Land use Zoning and Buffering zones
Growing mainly root crops such as taro and Yams
Build on elevated areas of the island
Build reliable communications networks that are secure.
Strict building codes which can withstand strong winds and rains.
Good meteorological services which leave people with adequate
time to prepare.
Educating public on how to prepare for a Cyclone.
Insurance policies in place
Identification of flood prone areas
Build flood proof structures such as stop banks
Have an emergency plan set-up
Grow crops that can be harvested before the cyclone season.
How other Countries Responded




NZ and Aussie military aid workers arrived and
assisted in urgent relief, such as dist of food and
medicines. Evacuation centres were set up to assist
hundreds of people whose homes were destroyed.
NZ Gave 5 million and the EU gave over 700,000. NZ
sent two airforce hercules plus ships with supplies to
help rebuild.
A donor team comprising representatives from seven
countries worked with NZ authorities to help with relief
efforts.
Seventy eight people were airlifted to NZ four of them
required medical treatment.
Cont


Re-establishment of agriculture and tourism
began.
Nzers and Niueans learnt a lesson and
rebuilt in more protected areas. It was
decided that the capital Alofi be relocated in
the centre of the island.
Hurricane Katrina!!!!



Katrina was a category 5 hurricane
(northern hemisphere) That hammered the
southern coast of the USA.
It caused the most extensive damage to the
state of Louisiana.
Katrina struck August 29th 2005.
Where did Katrina hit?



USA STATE MAP hand out.
Katrina hit the following states locate and
label them on your map.
Louisiana, Florida, Texas, Georgia,
Alabama, (Ohio,Kentucky floods)
The force of Katrina





2500mm of Rainfall fell over Louisiana.
8.5 metre storm surge
300 km/h winds
10 m storm waves.
Winds were sustained at 285 km/h for over
one minute!
Processes




Using pg 122 geog on edge:
Where did Katrina Form?
When did Katrina form?
When did Katrina make landfall with the
gulf Coast?
Processes



Hurricane Katrina occurred in 2005 and was the costliest
natural disaster in the USA’s history. 1836 people died, and it
caused $81 billion worth of damage.
Katrina formed over the Bahamas August 23rd and flew over
Florida as a category one hurricane. The storm then moved
into the gulf of Mexico where it strengthened into a category
5 hurricane and did most of its damage.
This Natural disaster caused substantial damage to the
natural environment in the USA but it was the social problems
which were the most well documented.
Processes






Katrina’s eye was 46.3 kilometres in diameter
Barometric pressure of 902 hpa
Wind speeds of over 280 kp/h
Hurricane Katrina formed over the Bahamas
The ocean was 27 degrees prior to the hurricane
forming
katrina
info\Hurricane_KATRINA_aweson_formation.wmv
Why was Katrina such a disaster…


Katrina bought with it floods, rain, wind and
storm surges just the normal stuff that a
cyclone brings…Absolutely!
So why was Katrina such a shocker?
Lousiana
Cultural Environment




Use Geography on the edge to explain the effects
of Katrina on the Cultural Environment.
http://www.youtube.com/watch?v=3RVHDlPqZWE
http://www.youtube.com/watch?v=IblL_rXpdu8&fe
ature=related
http://www.youtube.com/watch?v=2pD1aVJaRsM
&feature=fvsr
Cultural Environment.











Hurricane Katrina cost 81 billion US dollars (rebuilding)
Much of Louisiana lies below sea-level, Lake Ponchartrian and Mississippi river.
80% of the 1.3 million residents evacuated.
Louisiana Superdome provided shelter for over 26,000 people and provided food
and water for several days as the storm struck.
Three million people left without electricity.
The Airport was closed therefore people could not evacuate
One Murder and one suicide occurred at the Superdome
Dead bodies were seen floating around the streets of New Orleans
Many of the rich were able to evacuate while the poorer largely black community
were not able to evacuate.
Looters took what they could from stores.
The relocated evacuee’s caused massive crime spikes in neighbouring states who
took them in. Murders, robberies etc all increased with the influx of people from New
Orleans.
Natural Landscape


Katrina had massive effects on the Natural
Landscape…
Use Geography on the Edge to explain the
effects of Katrina on the Natural
Environment
The effects on the Landscape





As part of the clean-up effort the flooded land was pumped
into lake Pontchartrian. This water contained contaminants
such as raw sewage and has sparked scientific concern for
the community.
An area of 560 km2 was completely transformed into water
by Katrina
The storm surge also completely obliterated the Chandeleur
Islands.
Katrina caused substantial beach erosion and in some areas
completely destroyed coastal areas.
The land that was lost was breeding grounds for a number of
marine mammals, birds and fish.
Responding to…








62.3 billion in aid was given for the victims.
Housing assistance was provided for more than 700,000 applicants.
FEMA also paid for the hotel costs of 12,000 individuals.
100,000 people live in FEMA provided trailors.
Two weeks after the storm, more than half of the states were
involved in providing shelter for evacuees.
Kuwait donated $500 million, Qatar and The U.A.E each gave 100
million.
Other nations to give aid were South Korea (30 million), Australia
(10 million), India, China (5 million), NZ (2 million), Pakistan (1.5
million), and Bangladesh (1 million).
Many other nations provided aid in the form of tarps, medikits and
other aid.