Topic 1 - Hazardous Earth Flashcards
(135 cards)
1
Q
Where is the most solar radiation received?
A
At the equator
2
Q
Why is the most solar radiation received at the equator?
A
Due to the spherical shape of the earth, the atmosphere is thinnest at the equator and the distribution area of the solar radiation is larger at the poles whereas there is a smaller distribution area at the equator
3
Q
What causes changes in temperature throughout the year?
A
The earths movement and tilt causes changes in temperature throughout the year,
4
Q
What causes a low pressure zones?
A
When air is heated it becomes less dense and rises. As it rises it cools and clouds form. Because there is less air at the surface it is now a low pressure zone.
5
Q
What causes a high pressure zone?
A
Once air cools it becomes more dense and sinks. It warms as it cools and leaves clear skies. Because there is more air at the surface it is now a high pressure zone.
6
Q
What causes wind directions?
A
Winds are caused when air moves from high to low pressure areas as a result of heating and cooling. Because of the earths rotation wind is deflected to the right in Northern Hemisphere and to the left in the Southern Hemisphere. This is the Coriolis Effect
7
Q
What is the Coriolis Effect?
A
Wind being deflected to the right in the Northern Hemisphere and to the left in the Southern Hemisphere due to the Earths rotation.
8
Q
How do atmospheric circulation cells explain how heat is transferred around the world?
A
Air is heated at the equator, as it is heated it becomes less dense and begins to rise. The warm air spreads out to 30N and 30S. As the air reaches 30N and 30S, it cools and condenses, sinking back down to the ground, forming a high pressure zone. As winds blow from areas of high pressure to areas of low pressure, trade winds may then bring the air back to the equator to be reheated and westerlies may take the air to 60N and 60S. At 60N and 60S, the warmer air meets the colder polar air and is therefore less dense than the polar air and begins to rise. The air then spreads out the poles or back to 30N and 30S. Cold air at the poles may then return to 60N and 60S being carried by polar easterlies
9
Q
How do large ocean currents transfer heat around the world?
A
Surface currents are caused by winds from the Coriolis effect. These winds help transfer warmer water from the equator. Deep ocean currents also move water which is caused by differences in water density. This density difference is caused by saltier water at the poles due to water freezing. This looped process is called the Thermohaline Circulation.
10
Q
What is the Thermohaline Circulation?
A
The process of ocean currents moving heat around the world
11
Q
What are the circulation cells closest to the equator?
A
The Hadley Cells
12
Q
What are the circulation cells between the tropics and the poles?
A
The Ferrell Cells
13
Q
What are the most southern and northern circulation cells?
A
The Polar Cells
14
Q
What features are common at High Pressure Areas?
A
Low rainfall, arid, rarely cloudy
15
Q
What features are common at Low Pressure Areas?
A
High rainfall, often cloudy
16
Q
What is the Permanent zone of low pressure called?
A
The Inter-Tropical Convergence Zone, ITCZ
17
Q
What are the 6 natural factors that cause climate change?
A
Eccentricity, Obliquity (Tilt), Precession (Wobble), Asteroid Collisions, Volcanic Activity, Solar Output Variation
18
Q
How does eccentricity cause climate change?
A
Approximately every 100,000 years the shape of the Earths orbit around the sun changes. This means that sometimes the earths orbit is more circular, making the earth warmer (interglacier) and sometimes the earths orbit is more elliptical making the earth cooler (glacial)
19
Q
How does Obliquity cause climate change?
A
The earths poles are not perfectly at the top and bottom of the earth. The poles are rotated approximately 23.5* from a vertical position. This creates seasons north and south of the equator. Approximately every 40,000 years the angle of the tilt changes, this means that sometimes the Earth is tilted closer or further from the sun, this causes seasons to be less and more pronounced at different times.
20
Q
How many degrees are the poles from a vertical position?
A
23*
21
Q
How do Asteroid Collisions cause climate change?
A
When Large Cosmic material, such as asteroids, impact the earths surface they throw large amounts of dust up into the earths atmosphere. This can partially block solar radiation, causing global temperatures to cool and leading to glacial periods.
22
Q
How does Volcanic Activity cause climate change?
A
Major volcanic eruptions eject large quantities of ash and sulphur dioxide into the earths atmosphere. These are spread around the earths stratosphere by high level winds. This can block some solar radiation and cause the global average temperature to cool, this can lead to a glacial period
23
Q
How does Solar Output Variation cause climate change?
A
The suns output of solar energy varies in short cycles of about 11 years and larger cycles of several hundred years. Periods when solar output is reduced may cause the Earths climate to become cooler
24
Q
How does Precession (Wobble) cause climate change?
A
As the earth rotates on its axis, it does not do so perfectly. The earth actually “Wobbles” on its axis rather than rotating perfectly. As this happens the direction the axis is facing changes. This affects our seasons and creates either greater or smaller differences between summer and winter. This occurs over a period of approximately 24,000 years.
25
What are the 3 pieces of evidence for natural climate change?
Tree Rings, Ice Cores, Historical Sources
26
How do Tree Rings provide evidence for natural climate change?
Every ring in a tree roughly shows a year of growth. Changes in shape and size of tree rings can show conditions during that year. Warmer and wetter weather can show greater growth as the distance between tree rings is larger. Cooler and drier weather can show thinner as there is less growth . Damage to the tree can show there was a forest fire, suggesting warmer, drier, arid seasons
27
How do Ice Cores provide evidence for natural climate change?
Ice contains bubbles from each year. Scientists analyse the bubbles from each layer to see how much CO2 they contain. Scientists can also learn about the temperatures for each year by measuring relative amounts of different types of oxygen atoms in water. Pollution and volcanic ash can also be trapped in the ice
28
How do Historical Sources provide evidence for natural climate change?
Old photos, drawings, written records, diaries and the records of of dates at regular intervals are often not very accurate because they where not intended to record climate. However, they can still give us some evidence of recent climate events.
29
What does the greenhouse effect prevent happening to the earth?
it prevents the earth turning into a frozen wasteland
30
What is the most abundant gas in earths atmosphere?
Nitrogen, 78%
31
Which 4 human activities are enhancing the greenhouse effect?
Agriculture, Energy, Transport, Industry
32
How does Agriculture cause the enhanced greenhouse effect?
Trees absorb and store CO2. However, population growth and demand for food has led to deforestation and clearing for cattle farming and rice paddies. Deforestation stops the absorption of CO2, this leaves more CO2 in the atmosphere. Trees release the CO2 when cut down. Furthermore, human activities, such as cattle farming, produce methane which is 21X more powerful than CO2.
33
How does Energy cause the enhanced greenhouse effect?
Burning fossil fuels release CO2 which is a greenhouse gas. The demand for electricity is increasing due to an increasing population. As the demand increases so does the supply of electricity which is mostly generated by burning fossil fuels. The increase in CO2 production, which has increased by 30% since 1850, enhances the greenhouse effect
34
How does Transport cause the enhanced greenhouse effect?
Most vehicles burn fossil fuels which then release greenhouse gases. Car ownership is rapidly increasing in developing countries, this means there are more cars on the road (especially in urban areas). This then means more greenhouse gases are being emitted. As people travel on planes more, the amount of flights increases. Planes emit nitrous oxide, the amount of nitrous oxide emitted has increased 16% since 1850 and is 250X as powerful as CO2
35
How does Industry cause the enhanced greenhouse effect?
As the amount of disposable income increases, so does the demand for consumer goods. This causes the industry to increase, The industry uses lots of energy and some of the industrial processes release greenhouse gases. When cement is produced lots of CO2 is produced, industrial waste decays and releases methane. Halocarbons are 3000X as powerful as CO2 and is used in solvents and cooling equipment.
36
What are the 4 pieces of evidence to prove human activity is enhancing the greenhouse effect?
Declining Sea Ice, Global Temperature Rise, Sea Level Rise and Warming Oceans, Extreme Weather Events
37
How does Declining Sea Ice provide evidence that human activity is enhancing the greenhouse effect?
The extent of Arctic sea ice is declining more and more every year. Every year sea ice melts in the spring then forms again in the winter when the ocean temperature falls below -1.8*C, however due to warmer global temperatures more ice has melted than ever before. By 2012 the amount of floating sea ice had shrunk to less than half of that in 1979, the extent of sea ice in winter has decreased by more than 3% per decade over the last 35 years. This sharp decline in the extent of sea ice cannot be explained by natural cycles indicating human interference . Boats are now able to travel through the northwest passage and northern sea route due to the lack of arctic ice, however this causes sea levels to rise.
38
How does Global Temperature Rise provide evidence that human activity is enhancing the greenhouse effect?
Global average temperatures have been rising steeply since the 1950's, more rapidly than ever before. Temperatures have increased by 1*C since 1880 and are expected to rise by 0.3 - 4.8*C by 2100. Furthermore, the top 10 hottest years on record have all been since 1998. This shows that human activity increases global temperatures
39
How does Sea Level Rise and Warming Oceans provide evidence that human activity is enhancing the greenhouse effect?
Between 1870 and 2010 sea levels have risen by 210mm, there are 2 factors that caused this: Eustatic Sea Level Rise and thermal expansion. Eustatic sea level rise is when warmer temperatures cause glaciers to shrink and for ice sheets to melt. The melting of ice on land means that Water stored on land as ice in places such as greenland and antarctica melt and release water back into the ocean causing sea levels to rise. Thermal expansion is when the ocean expands due to it getting warmer, scientists estimated that this accounts for half of the measured rise in sea levels
40
How does Extreme Weather Events provide evidence that human activity is enhancing the greenhouse effect?
Since 1950 there has been a higher frequency of heat waves in many areas and fewer cold weather extremes. In the UK, more rainfall records were broken in 2010-2014 than in any decade on record, even after only half a decade. 2013 was one of the wettest years on record and December 2015 was the wettest month ever recorded in the UK
41
What are the possible consequences of Climate change?
Uninhabitable land, Lower Crop Yields, More extreme weather, Impact on Farming
42
What is the impact Uninhabitable land of on People?
Some areas could become so hot and arid they're difficult or impossible to inhabit. Low-lying coastal areas could be lost to the sea or flood. This could lead to migration and overpopulation in other areas
43
What is the impact of Lower Crop Yields on People?
This could increase malnutrition, Ill Health and death from starvation (Particularly in lower latitude countries)
44
What is the impact of More extreme weather on People?
More money has to be put into predicting and reducing the impact from extreme weather events and rebuilding afterwards
45
What is the impact of Impact on Climate change on farming?
Some crops in higher latitude countries could benefit from warmer temperatures. However some crops could suffer, e.g maize crops have shrunk
46
What is the coriolis effect?
a strong force created by the earths rotation
47
What is the eye of the storm?
the centre of a tropical cyclone
48
What are characteristics about the eye of the storm?
clear sky and no wind
49
What is seasonal Distribution?
how something such as a tropical cyclone occur at different times of the year
50
What is the source area?
The region in which a tropical storm first forms
51
What is the Track?
the path followed by a Tropical Cyclone
52
Where is the source areas of Tropical Cyclones?
Between the tropic of capricorn and the tropic of cancer
53
How warm does the ocean have to be for Tropical Cyclones to form?
above 26.5*C
54
What is the Inter Tropical Convergence Zone?
an area of permanently low pressure where tropical cyclones commonly form
55
How do Tropical Cyclones form?
Strong clusters of thunderstorms drift over warm waters. Very warm air from the storm and the ocean surface combine and begin to rise. This creates low pressure at the surface. Trade winds and the coriolis effect cause the storm to dart spinning. Risinig warm air causes pressure to decrease at higher altitudes. Air rises faster and faster to fill this low pressure, in turn drawing more and more warm air off the sea and sucking cooler, drier air downwards. As the storm moves over the ocean it picks up more warm, moist air. Wind speeds start to increase as more air is sucked into the low pressure centre. It can take hours or several days for a depression to grow into a full-formed cyclone. Hurricanes are made up of an eye of calm winds and low pressure surrounded by a spinning vortex of high winds and heavy rainstorms.
56
When do tropical cyclones form in the northern hemisphere?
late summer
57
When do tropical cyclones form in the southern hemisphere?
mid january to march
58
How tall are tropical cyclones?
12-15km
59
Where are the wind speeds fastest?
At the eye wall
60
What clouds are Tropical Cyclones made from?
Cumulonimbus Clouds
61
Which direction do winds rotate at the top of the storm?
Outwards
62
What are the hazards of Tropical Cyclones?
High Winds, Intense Rainfall, Storm Surges, Coastal Flooding, Landslide
63
What are the impacts of High Winds
Homelessness and buildings damage, injuries/death by flying debris. Power cables damaged. They can uproot trees and destroy habitats/biodiversity
64
What are the impacts of Intense Rainfall
Flooding can cause people to drown in the fast moving water nad can flood sewage, causing it to overflow and contaminate water sources
65
What are the impacts of Storm Surges?
This can damage coastal defences and flow far inland. They can contaminate freshwater sources and cause flooding. They can also erode beaches and damage coastal habitats.
66
What are the impacts of Coastal Flooding?
They can destroy buildings and put peoples lives at risk due to drowning. They can impact the tourism industry and affect farming.
67
What are the impacts of a Landslide?
Due to high levels of rain, the soil becomes saturated. This causes the soil to slide down the slope. This is easier if the underlying rock is impermeable. This can cause massive devastation to any settlements at the base of the slope and could potentially block rivers and cause flooding.
68
What is the saffir simpson wind scale?
it is a 1-5 rating based on the hurricanes wind speed, it estimates the potential property damage
69
What are the 6 reasons some places in the world more vulnerable to the impacts of a tropical cyclone?
Building Type, Relief of Land, Shape of Coastline, Islands, Distance from Coast, Social factors
70
How does Building Type make locations more vulnerable?
Building type make locations more vulnerable because more developed areas may have infrastructure with defences against the strong winds and storm surges.
71
How does Relief of Land make locations more vulnerable to tropical storms?
Relief of Land make locations more vulnerable because areas of low relief are more vulnerable than areas of high relief. This is because they are more exposed to flooding and the high wind. However, areas of high relief are more susceptible to land slides
72
How does Shape of Coastline make locations more vulnerable?
The shape of the coastline make locations more vulnerable because they may be in the track of the Tropical Cyclone. They may also allow the Tropical Cyclone to be close enough to the sea or for estuaries to fuel the Tropical Cyclone.
73
How do Islands make locations more vulnerable?
Being an island make locations more vulnerable because there is no lost energy due to the surrounding water fuelling the Tropical Cyclone
74
How does the Distance from the Coast make locations more vulnerable?
The distance from the coast make locations more vulnerable because if in the track of the cyclone they will experience the cyclone whilst it is still at its strongest, whereas further inland the cyclone will have lost some of its energy and not cause as much damage.
75
How do Social Factors make locations more vulnerable?
Social factors make locations more vulnerable because
76
What is preparation?
Preparation is what we do before the event to minimise the impacts.
77
What is Response?
Response are the events afterwards that are put in place to help get life back to normal
78
How does Forecast/Tracking help reduce the impacts of the Tropical Cyclone?
This gives people time to protect their homes and businesses and also evacuate the area in time
79
How does Warning/Evacuation help reduce the impacts of the Tropical Cyclone?
This gives people enough time to evacuate areas along evacuation routes. This reduces deaths and injuries.
80
How does Building Design help reduce the impacts of the Tropical Cyclone?
Defences can be built along the coast to reduce damage from storm surges. Buildings can also be designed to withstand the surge
81
How does Rescue help reduce the impacts of the Tropical Cyclone?
This can help save lives as many people could be trapped under rubble or in buildings. Responding to this quickly and rescuing them can help reduce the impact.
82
How does Rebuild help reduce the impacts of the Tropical Cyclone?
Rebuilding quickly from the Tropical Cyclone can help reduce the impacts in the long run. If they respond quickly and rebuild, they can help restore normal life and rebuild society.
83
How does the wealth of a country impact the level of protection a country has against tropical cyclones?
Wealthier countries can spend more on defences to reduce the impact from the Tropical Cyclone. They can also spend more on the response to the Cyclone.
84
What were the impacts on the environment caused by hurricane katrina?
Coastal habitats and breeding beaches were damaged, coastal conservation areas were also destroyed. Flooding damaged Oil Refineries causing massive oil spills.
85
What where the impacts on the environment caused by cyclone nargis?
The Irrawaddy Delta was the hardest hit and over 14,000 KM^2 of land was flooded. 38,000 hectares of mangrove forests were destroyed.
86
What where the impacts on people caused by hurricane katrina?
over 1800 people where killed. Hundreds of Thousands of people where left homeless as 300,000 homes where destroyed. 3 million people where left without electricity and over 230,000 people lost Jobs. Rods and bridges where destroyed
87
What where the impacts on people caused by cyclone nargis?
Over 140,000 people where killed, 450,000 houses where destroyed and 350,000 damaged. 65% of rice paddies in the Irrawaddy Delta where damaged and many people suffered from diseases caused by poor sanitary conditions and contaminated water.
88
What forecasting did the USA have?
They had sophisticated tracking systems to predict when and where the hurricane would hit
89
What forecasting did Myanmar have?
They do not have a dedicated monitoring system or radar network, however they where informed by other countries 48 hours in advance
90
What warning/evacuation did the USA have?
70-80% of residents in New Orleans where evacuated and given a warning 3 days prior, however many people evacuated too late and caused massive traffic jams
91
What warning/evacuation did Myanmar have?
They where informed by the indian weather agency 48 hours in advance and issued warnings on TV and Radio. However, the warnings did not reach people in rural areas and there was not any emergency preparations or evacuation routes.
92
What Defences did the USA have?
Levees where in place as flood defences, however the levees failed due to poor maintenance
93
What Defences did Myanmar have?
They had mangrove forests which act as natural flood defences, however much of these forests had been cut down prior to the Cyclone
94
How much of New Orleans was flooded?
80%
95
How many people where killed by Hurricane Katrina?
1800
96
How many people where killed by Cyclone Nargis?
140,000
97
What category was Cyclone Nargis?
4 at landfall
98
What is the outer layer of the earth?
The crust (The lithosphere)
99
What is the second layer of the earth?
The upper mantle (Asthenosphere)
100
What is the third layer of the earth?
The lower mantle
101
What is the fourth layer of the earth?
The outer core
102
What is the centre of the earth?
The inner core
103
What is the centre of the earth?
The inner core
104
What features are produced at a convergent plate boundary (oceanic and continental)?
A subduction zone, trenches, earthquakes and composite volcanoes
105
What features are produced at a convergent plate boundary (continental and continental)?
fold mountains, earthquakes
106
What features are produced at a divergent plate boundary?
earthquakes, shield volcanoes
107
What features are produced at a conservative plate boundary?
earthquakes and tsunamis
108
What dangers are produced from volcanoes?
Ash, Acid Rain, Pyroclastic Flow, Parasytic Core, Lahar, Lava Flow, Volcanic Bombs
109
How are tsunamis formed?
2 plates move towards each other at convergent plate boundaries, 1 plate is subducted below the other plate. As the plates move towards each other, more and more friction is created and the pressure builds. The pressure gets to a point so high it is released, causing an earthquake. This earthquake resulting from the sudden movement of tectonic plates causes a massive upward wave called a tsunami that goes in both directions. As the tsunami reaches shallower waters it begins to slow down but gain height and energy. If a tsunami has a deep focus, there is more water displacement and therefore a larger tsunami forms.
110
What is a composite volcano?
A composite volcano is found at a convergent plate boundary. It is made from alternating layers of lava and ash. It has high silica content lava meaning that it is viscous. The viscous flows a short distance before cooling. It has violent but infrequent eruptions. These can include lava bombs and pyroclastic flows or lead to lahars
111
What is a shield volcano?
A shield volcano is found at a divergent plate boundary. It is low with gentle sloping sides. It s formed by low silica content lava. Lava flows a long distance before cooling. eruptions are frequent but relatively gentle
112
What is a hotspot volcano?
Small long lasting regions exist within the mantle. These are mantle "plumes". It is superheated rock, not magma. It is a constant source of heat called a hotspot, these plumes rise to the surface and form a hotspot volcano
113
What was the Japan Tohoku Earthquake 2011?
It was a 9.0 magnitude earthquake in north-east Japan. The pacific plate was subducted under the Eurasian plate. The Japanese trench triggered a tsunami. The focus was 30km below the seabed and the epicentre was 130km east of the coast
114
What were the primary impacts of the Japan Tohoku Earthquake 2011?
* 667 - 1479 (roughly 1000) deaths from direct impacts
* Buildings, roads, and railways severely damaged
* Power, water, and sewage disrupted
* Land 400km from the epicentre suffered liquefaction
* 1 Dam collapsed and 2 nuclear power stations where fractured
* $235 billion worth of damage
115
What were the secondary impacts of the Japan Tohoku Earthquake 2011?
* Over 17,000 deaths from drowning in the tsunami
* Over 5,000 people reported missing or injured
* Over 127,000 buildings collapsed, 1.2M severely injured
* More than 2000 roads, 56 bridges, and 26 railway lines destroyed
* The Fukushima dam burst
* Tsunami caused 2 nuclear meltdowns
* Over 230,000 people where made homeless
* 93% of the deaths where from drowning
116
What was the short term relief of the Japan Tohoku Earthquake 2011?
* International aid and search and rescue teams where brought in
* Rescue workers and soldiers were sent to help deal with the aftermath
117
What was the long-term relief of the Japan Tohoku Earthquake 2011?
* Transport, communications, and power supplies were restored in following weeks
* 10's of thousands of prefabricated houses where set up in Sendai
118
What was the preparation of the Japan Tohoku Earthquake 2011?
* Earthquake warnings where given so that people can get to higher ground
* Bullet train network has automatic braking systems
* new buildings are built with earthquake protection such as cross bracing steel beams, computer controlled weights, and deep foundations
* Older buildings are retrofitted with said features
* Sea walls are in place to defence against Tsunami's
119
What was the Haiti Earthquake 2010?
The Haiti Earthquake of 2010 was a 7.0 earthquake that was at a conservative plate boundary between the north American plate and Caribbean plate. It had a shallow focus of 13km and an epicentre of just 25km south west of Port-au-Prince
120
What were the primary impacts of the Haiti Earthquake 2010?
* 316,000 deaths and 300,000 injuries
* 1.5 million made homeless
* 180,000 homes destroyed
* all 8 hospitals collapsed or where badly damaged
* 5,000 schools damaged and 3 universities collapsed
* Port communications and major roads damaged beyond repair
121
What were the secondary impacts of the Haiti Earthquake 2010?
* Water supply system damaged - cholera outbreak killed over 8,000 in camps
* Port was destroyed, difficult for aid to arrive
* Clothing factories damaged, these provided over 60% of Haiti's exports
* 1 in 5 jobs where lost
* looting and crime increased as police and government collapsed
* Tourism stopped
122
What was the short term relief of the Haiti Earthquake 2010?
* International aid and search and rescue teams where flown in to help trapped people
* Food, water, medical supplies and temporary shelters where supplied by the USA
* The UK's disaster commission raised more than £100 million in supply aid
However,
* Government buildings where destroyed so emergency aid was initially slow
123
What was the long-term relief of the Haiti Earthquake 2010?
* The government moved 235,000 people from Port-au-Prince to less damaged cities
* 3/4 of the damaged buildings where repaired, they now have earthquake resistant re-build techniques such as being made of tyres, straw bales, or bamboo
124
What are trade winds?
Winds blowing towards the equator from 30°N and 30°S from the eastern direction, they bring colder air back towards the equator to be reheated
125
What are westerlies?
A wind blowing from 30°N and 30°S to 60°N and 60°S from the western direction
126
What are polar easterlies?
Winds that blow from the poles to 60°N and 60°S
127
What geological period are we currently in?
The quaternary period, we have been in it for the last 2.6 million years
128
What are the 3 tectonic hazards?
* Earthquakes
* Volcanic eruptions
* Tsunamis
129
How can earthquakes be predicted?
Earthquakes cannot be reliably predicted but there are are some methods:
* Lasers can be used to detect the movement of tectonic plates before an earthquake
* Vibrations in the earths crust can be monitored using seismometers. If vibrations increase, it could mean that there is going to be an earthquake
* Scientists can measure gases that escape from cracks in the crust just before an earthquake (e.g. radon)
* Rocks will crack and expand because of the increased pressure just before an earthquake
130
How can volcanic eruptions be predicted?
Volcanic eruptions can be predicted if the volcano is well-monitored and tell-tale signs of a volcanic eruption are spotted:
* Tiny earthquakes and changes in the shape of the volcano (e.g. bulges in the land where magma has built up under it) all mean an eruption is likely
* Thermal imaging cameras can be used to detect changes in temperature around the volcano. Temperatures increase before an eruption
* Scientists can analyse the gases escaping from a volcano. Volcanoes emit lots of sulfurous gases before an eruption
131
Which type of crust is more dense?
Oceanic crust is more dense than continental, this is why is is subducted at a subduction zone at a convergent plate boundary
132
What are 2 reasons why it is difficult to predict sea level projections
* Countries and corporations may change their greenhouse gas emissions in the future
* Some natural factors are not completely understood (i.e eccentricity can affect global temperatures, and therefore sea levels, or volcanic and cosmic activity can affect global temperatures, and therefore sea levels)
133
What was the US response to Hurricane Katrina?
* The US government mobilised 58000 National Guard troops and provided $62.3bn aid for victims.
* Over 70 countries pledged monetary assistance to the USA following Katrina with NGO’s such as the Red Cross providing assistance.
* Due to higher levels of development, the US government was able to mobilise medical experts, search and rescue equipment and staff trained in emergency disaster management to aid those affected.
* Water that flooded New Orleans was pumped into Lake Pontchartrain
* US Congress allocated $62 billion in aid, much of this went towards rebuilding flood defence systems (such as the broken levees)
134
What was Myanmar's response to Cyclone Nargis?
* External aid was not allowed for 3 weeks due to scepticism by the military government as they believed letting aid agencies in would lead to destabilisation
* UK was eventually allowed to send £17 million and an international relief team to coordinate relief effort
135
How does an earthquake trigger a tsunami?
The movement of tectonic plates causes a large volume of water to be displaced, which forms a tsunami
