91007 DEMONSTRATE GEOGRAPHIC UNDERSTANDING OF ENVIRONMENTS (NIUE) THAT HAVE BEEN SHAPED BY TROPICAL CYCLONE HETA 2004 You need “to fully explaining aspects of how extreme natural event(s) shape natural and cultural environments using geographic terminology and concepts, and showing insight, integrating detailed supporting evidence”. Geographic understanding refers to an understanding of how natural environments and people interact and the consequences of that interaction. Extreme natural event(s) refers to one type of naturally occurring hazard that has a major impact on people’s lives, such as: earthquakes, floods, tsunami, landslides, tropical cyclones. Supporting evidence refers to specific, relevant information from different environments. Environments refer to either different places that are affected by one type of extreme natural event or different places that are affected by a single extreme natural event. Integrating refers to relevant examples being woven throughout the evidence to support explanations.

91007 DEMONSTRATE GEOGRAPHIC UNDERSTANDING OF ENVIRONMENTS (NIUE) THAT HAVE BEEN SHAPED BY TROPICAL CYCLONE HETA 2004 Exam questions are selected from: N atural 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).

CYCLONE HETA: NIUE Cyclone Heta reached hurricane strength on New Year's Day 2004 in a deserted part of the Pacific Ocean. After travelling to the Tokelau Islands it retraced its track, heading for Western Samoa where it caused heavy damage. From 4-6 January it headed in a beeline for Niue, while increasing in strength to the most ferocious storm known to man, a class five hurricane with wind speeds of over 250km/h. Also accelerating its speed to over 30km/h, it turned its most devastating flank to Niue, destroying the capital village Alofi and killing a nurse who sacrificed her life to save her baby.

NIUE LOCATION Niue is a small independent state, located between Tonga on the west and the Cook Islands further east. Niue is only a small limestone island, measuring about 23 by 18 km with a total surface area of 250km2. It rises to only 68m above sea level, with most of the island no higher than 30m. Its population is estimated at , with around tourists enjoying the clear waters, caves and calving humpback whales in winter (Aug-Oct). However, most of the 20,000 Niueans live in Auckland, New Zealand and another 2000 in Australia. Located 19 degrees south of the Equator, Niue experiences regular trade winds from the south-east, which renders the coast of this part of the island inhospitable. Understandably, the NW side of the island is more sheltered, reason why most of its population and tourist activities reside here, and goods are landed here by ship. But this is also the side facing the path of cyclones and their most vicious winds. Niue does not have a protected harbour but a shallow quay, approached by boats along the line joining two navigational lights. Locally based boats and fishing vessels need to be lifted out of the water when storms rage.

CULTURAL FEATURES THAT MAKE NIUE VULNERABLE Main settlement on NW coast Eg capital Alofi, airport, main coast road. Most developments coastal eg hospital. Hotel Niue Huanaki culture centre Fuel tanks and telecom dish Niue adventure and Alofi Rentals, Dive Niue

NIUE ADVENTURE AND ALOFI RENTALS

HUANAKI CULTURE CENTRE

FUEL TANK

HOTEL NIUE

DIMITRY VILIAMU’S HOME

NATURAL FEATURES THAT MAKE NIUE VULNERABLE limestone island23 by 18 km 68m above sea level, with most of the island no higher than 30m. NW side of the island is more sheltered Niue does not have a protected harbour but a shallow quay Regular trade winds from the south-east, which makes the SE coast inhospitable

NATURAL PROCESSES THAT OPERATE TO PRODUCE THE TROPICAL CYCLONE Heta formed at 10 degrees south of the equator where trade winds are strong and The Pacific ocean was heated to 27 degrees C. The waves produced by the trailing winds are as a result much more powerful such that a hurricane's left flank (in the southern hemisphere) is the most damaging one. As cyclone Heta passed 70km west of Niue, it presented its most devastating flank to the island.

Tropical cyclones use warm, moist air as fuel. That is why they form only over warm ocean waters near the equator. The warm, moist air over the ocean rises rapidly upward from near the surface and becomes saturated with evaporated moisture. This means that there is less air left at the surface (i.e. low pressure). Air from surrounding areas with higher air pressure pushes in to the low pressure area to try to equalise the pressure. Then that “new” air becomes warm and moist and rises, too. As the warm air continues to rise, the surrounding air swirls in to take its place. Trade winds cause the moist air to spin inwards. As the warmed, moist air rises and cools off, the water in the air forms towering cumulonimbus thunderclouds (because there is a huge amount of condensation). The whole system of clouds and wind spins and grows, fed by the ocean’s heat and water evaporating from the surface. The diagram below shows a cross section through a tropical storm. As the storm system spins faster and faster, an eye forms in the centre. It is very calm and clear in the eye, with very low air pressure. BBC animation - the formation of a hurricane BBC animation - the formation of a hurricane ure/ stm

Latitudes 5-15 N and S of the equator Sea temperature C Warm, Moist air rises and Starts to condense as it cools Forming towering cumulo nimbus clouds Inter Tropical Convergence Zone Where NE and sE Trade winds meet Is an area of rising air Coriolis force, caused by the rotation of the earth, Starts to rotate the rising air in a clockwise direction (S Hemisphere) around an eye that is calm Once the tropical cyclone forms, it Moves in a SE direction over the warm ocean, Which provides energy,moisture and heat. As it moves to lower latitudes, the ocean becomes cooler, it loses energy And becomes a depression

How has TC Heta caused changes to the natural environment of Niue? 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. 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.

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

How has TC Heta caused changes to the cultural environment of Niue? One life lost. The capital city of Alofi, which took the brunt of the storm, was devastated as most of the commercial and financial areas were wiped out by the high winds. 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. Hotel Niue destroyed. Damage to communications and electronic infrastructure was also great as the storm damaged a satellite dish and disabled 75% of Niue's computer database. $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.

STORM SURGES AFFECT LOW ISLANDS

HOW DIFFERENT GROUPS OF PEOPLE HAVE HOW HAVE DIFFERENT GROUPS OF PEOPLE RESPONDED TO THE EFFECTS OF THE EXTREME NATURAL EVENT(S). 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.

Clean-up costs $20 million (emergency response and start of recovery) Estimated cost of rebuilding is over $25 million. 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. the capital Alofi be relocated in the centre of the island.

THE DAMAGE HETA CAUSED ON TONGA, NIUE, AND AMERICAN SAMOA WAS ESTIMATED AT $150 MILLION DOLLARS (2004 USD), WITH MOST OF THE DAMAGE OCCURRING IN AMERICAN SAMOA (Samoa) Formed: January 2, 2004 ( ) Dissipated: January 8, 2004 ( ) Highest winds: 215 km/h (130 mph) (10-minute sustained) 260 km/h (160 mph) (1-minute sustained) Lowest pressure: 915 hPa (mbar) Fatalities: 1 direct Damage: $150 million (2004 USD) $170 million (2009 USD) Areas affected: Samoa, Tonga, Niue, American Samoa In Tonga, Heta's strong winds damaged houses and caused severe crop damage, mostly to breadfruit, mango, tava and bananas. In Tafahi and Niuatoputapu, % of the homes and buildings were destroyed by the cyclone's powerful, Category 5 winds. However, because of advanced warnings, there were no deaths or injuries. Structural damage in Tonga amounted to $160,000 dollars (2004 USD).

TRACK OF HETA TO SE.

SAMOA Seawalls constructed after the major cyclones Ofa and Val in and other emergency measures helped to reduce the damages caused by Heta. Power, water, transport and other services were restored within a week after the cyclone passed near the Island. Nonetheless, the cyclone caused major damage. Trees, crops and coastal infrastructure were destroyed or damaged. Damage added up to an estimated US$ 25 million -- beyond the financial capacity of the government. Also, the fringing reef that provides natural protection was also badly damaged. Samoa's international airport has already been closed

AMERICAN SAMOA American Samoa on Sunday, uprooting banana trees, swirling debris into the streets With sustained winds of 144 mph and gusts of 173 mph, Heta was moving south at about 12 mph Sunday and was forecast to pass within 150 miles southwest of American Samoa's capital of Pago Pago Hundreds of people hoping to travel from Pago Pago to Apia or vice versa were stranded, and Hawaiian Airlines canceled a flight from Honolulu to Pago Pago — some 2,300 miles south — on Sunday. In Pago Pago, high school football players from Hawaii were reportedly riding out the storm in their hotel rooms. Three people were washed out to sea at Fagasa, but managed to make it safely back to shore as families in coastal areas were advised to move to higher ground Pago Pago International Airport closed