Unit 1: Section A: The challenge of natural hazards Flashcards
1
Q
Define natural hazard
A
A natural process which could cause death, injury or disruption to humans or destroy property and possessions
2
Q
Define natural disaster
A
A natural hazard that has already happened
3
Q
Define natural event
A
A natural process which doesn’t pose any threat to human activity
4
Q
What are the 2 main types of hazard?
A
1) Geological hazard
2) Meteorological hazard
5
Q
What is a geological hazard?
A
-A hazard caused by land and tectonic processes
-Examples are earthquakes and volcanoes
6
Q
What is a meteorological hazard?
A
-A hazard caused by weather and climate
-An example is a tropical storm
7
Q
Define hazard risk
A
The probability of people being affected by a hazard
8
Q
What are the main factors that affect hazard risk?
A
-Population density
-Poverty/Capacity to cope
-Type of natural hazard
-Frequency of hazard
-Magnitude of hazard
9
Q
How does population density affect hazard risk?
A
More people in an area when a natural event occurs, the higher the hazard risk
10
Q
How does poverty/capacity to cope with a hazard affect the hazard risk?
A
-In poorer parts of the world people may be forced to live in areas with a high chance of hazards happening
-In LICs people may not be able to afford defences
-In addition the better a population can cope with an event the lower the risk of them being affected
11
Q
How does the nature of the hazard affect the hazard risk?
A
-The risk of some hazards is greater than others
-Natural hazards that occur more often have a higher risk
-More severe hazards TEND to have a greater impact and risk
12
Q
Define the term primary effects
A
The immediate impacts caused by a natural hazard
13
Q
What are the main primary effects of a natural hazard?
A
-Buildings and roads are DESTROYED by natural hazards (Earthquakes/volcanoes/tropical storms)
-People may be injured or killed (e.g when a building collapses)
-Crops and water supplies may be damaged or contaminated
-Electricity cables, gas pipes, water pipes. sewage pipes and network communications may be damaged CUTTING OFF supplies
14
Q
Define the term secondary effects
A
The effects that occur later on often the result of the primary effects
15
Q
What are the main secondary effects after a natural hazard?
A
-The initial hazard may trigger other hazards (earthquakes may trigger tsunamis)
-Aids and emergency vehicles CAN’T get through because of blocked roads and bridges - May lead to MORE deaths
-Shortage of clean water and lack of sanitation makes it easier for DISEASE to spread
-FOOD SHORTAGES Can occur if crops are damaged and livestock are killed
-The country’s economy can be weakened - damage to businesses can cause unemployment and the reconstruction can be expensive
16
Q
What are the immediate responses to a natural hazard?
A
-Evacuate people (before the hazard occurs if possible)
-Treat the injured people and rescue anyone
-Recover dead bodies to prevent disease from spreading
-Provide temporary supplies of electricity and gas if necessary
-Provide FOOD, DRINK and SHELTER
-Foreign governments or charities may send aid workers, supplies or financial donations
17
Q
What are the long term responses to a natural hazard?
A
-Repair homes or rehouse people
-Repair or rebuild buildings, roads, railways and bridges
-Reconnect broken electricity, water, gas and communication connections
-Improve forecasting, monitoring and evacuation plans
-Boost economic recovery (E.g tourism)
18
Q
What are the layers of the earth?
A
-Crust
-Mantle
-Outer core
-Inner core
19
Q
What are the properties of the core?
A
-Core is extremely hot and has temperatures of up to 5500 degrees Celsius
-The inner core is more solid due to the pressure
-The outer core is more of a liquid
20
Q
What are the properties of the mantle?
A
-Made up of 2 layers
-The uppermost layer is called the LITHOSPHERE and is the coolest and solid
-As you move closer to the core the mantle becomes more fluid (like custard) and the temperature increases
-This is called the aesthenosphere and is the main source of magma
21
Q
What are the 2 types of crust?
A
-Oceanic crust
-Continental crust
22
Q
What is the earths crust divided into?
A
Tectonic plates
23
Q
What are the properties of the oceanic crust?
A
-Young rock (<200 million years old)
-Thin (6-20km thick)
-Composed of basalt
-Can be renewed/destroyed
24
Q
What are the properties of continental crust?
A
-Old rock (>1500 million years)
-Thick (20-70km thick)
-Composed of granite
-Cannot be renewed/destroyed
25
What causes the tectonic plates to move?
-Convection currents
-Slab pull
-Ridge push
26
What is the continental drift theory?
-The theory of plate tectonics is linked with the fact that the earth's crust moves
-The theory states that 200 million years ago there was a supercontinent called Pangea
-Thus theory helps explain the formation of the world today
27
What is the place where plates meet called?
Plate margins or plate boundaries
28
What is ridge push?
-As plates move apart magma rises
-The magma then cools forming new plate material
-As this cools it becomes denser and slides down away from the ridge
-The force of this causes plates to move away from each other
29
What is slab pull?
-At a subduction boundary a denser heavier plate subducts the less dense plate
-As the plate gets pulled underneath by gravity the force of this pulls the rest of the plate with it
30
What are the types of plate margin?
-Destructive
-Constructive
-Conservative
-Collision
31
What happens at destructive plate boundaries?
-This occurs when one continental plate moves towards an oceanic plate
-The denser oceanic plate then subducts and gets destroyed
-This creates gas-rich magma
32
What natural hazards occur at destructive plate boundries?
-Volcanoes
-Earthquakes
33
What happens at collision plate boundaries?
-When two continental crusts collide
-They squeeze together as they have the same density forming fold mountains
34
What natural events happen at collision plate boundaries?
Earthquakes only
35
What is an example of a destructive plate margin?
The Nazca plate subducts the South American plate
(On diagrams Nazca on the left south american on the right)
36
What is an example of a collision plate boundary?
The Indian plate collides with the Eurasian plate
(Indian on the left Eurasian on the right)
37
What happens at constructive plate margins?
This is where two plate boundaries move apart from each other
-Magma then rises filling the gaps
-This then cools creating new crust
38
What is an example of constructive plate margins?
Eurasian plate and the North American plate - forming the mid Atlantic ridge
(North American on the left Eurasian on the right)
39
What happens at conservative plate boundaries?
-This happens when two plates are either moving sideways past each other
-Or moving in the same direction at different speeds next to each other
-Crust isn't created or destroyed
40
What is an example of a conservative plate boundary?
Pacific plate and the north american plate - forming the San Andreas fault
(Pacific plate on the left north american on the right)
41
Which natural events happen at constructive plate boundries?
-Earthquakes
-Volcanoes
42
Which natural events happen at conservative plate boundries?
-Earthquakes only
43
How do volcanoes form at destructive plate margins?
-The denser oceanic crust subducts into the mantle and melts
-This forms magma which rises through cracks called vents
-The magma erupts at the surface (Now called lava) forming a volcano
44
What type of volcano forms at destructive plate boundries?
Composite volcano
45
What are the properties of composite volcanoes?
-They have steep sides which are made up of alternating layers of ash and lava
-Lava is sticky and viscous (acidic)
-Eruptions are violent due to a high gas content
-However eruptions don't happen often
46
How are volcanoes formed at constructive plate boundaries?
-As the plates move apart, magma rises up from the mantle
47
What type of volcano is formed at constructive plate boundries?
Shield volcanoes
48
What are the properties of shield volcanoes?
-Wide base and gently sloping sides
-Lava is runny and flows a long way
-Lava is basic (Not acidic)
-Frequent eruptions
-However they are not violent
49
Define the focus
The point where the earthquake is generated
50
Define the epicentre
The point on the earth's surface right above the focus
51
Define seismic waves
The form in which energy is released from the focus
52
Define fault lines
Fractures or zones of fractures where significant displacement occurs
53
How are earthquakes formed at destructive plate boundries?
-Formed at the subduction zone
-Where tension builds as one plate gets stuck when they move away from each other
-The plate eventually jerks past each other sending out shock waves
54
How are earthquakes formed at constructive plate boundries?
Tension builds along cracks (fault lines) as the plates move away from each other
-Sending out shock waves
55
How are earthquakes formed at conservative plate boundries?
-Tension builds up when the plates are grinding past each other
-The start to stick and may get stuck
-The plates suddenly jolt apart releasing shock waves
56
Where are the seismic waves strongest?
At the focus
As they spread out they get weaker
57
What are the methods of measuring the magnitude of earthquakes?
-Richter scale
-Mercalli scale
58
What is the richter scale?
-The richter scale uses a seismograph to measure the difference of speed between P-waves and S-waves
-It is a logarithmic scale
-So a magnitude of 7 is TEN times more powerful then a magnitude of 6
-This is more scientifically accurate than the Mercalli scale but requires specialist equipment
59
What is the Mercalli scale?
-The Mercalli scale uses a range of 1-8
-He based the scale of the earthquake depending on the damage caused
-1 being not damaging 8 being catastrophic
-It isn't scientifically accurate yet doesn't require specialist equipment
60
What are the types of seismic waves?
-Surface waves
-P-waves
-S-waves
61
What are the properties of p-waves?
-They are the first waves to hit
-They can travel through solids and liquids
-They cause buildings to move up and down and are the least damaging
-So buildings may survive
62
What are the properties of S-waves?
-They are the second waves to hit
-They can only move through solids
-They move buildings side to side
63
What are the properties of surface waves?
-They are the most damaging
-They go up and down like waves on water
-This causes buildings to twist and collapse
-These are the last to hit
64
What are the hazards from volcanoes?
-Tephra
-Pyroclastic flow
-Lava
-Lava bombs
-Gas
-Lahars
65
What is tephra?
A mixture of ash and lava bombs which travels long distances
66
What are the impacts of tephra?
-Can destroy cars and any mode of transport
-Can disrupt travel
-Causes roofs to cave in under the weight
-Covers farmland and landscapes
67
What is pyroclastic flow?
-The most deadly of all the hazards
-A mixture of hot poisonous gas and ash that is blasted into the atmosphere
-It then tumbles down the side of the volcano at a high velocity
68
What are the impacts of pyroclastic flow?
-Hot gas kills people
-Will bury whatever is in its path
69
What are lava bombs?
A mass of molten rock ejected during an eruption
70
What are the impacts of lava bombs?
-Could severely injure people
-Can cause secondary fires and damage buildings
71
What is the gas released from a volcano?
-The invisible gas makes up the magma
-They can escape before an eruption
-This can kill people as it is poisnonous
72
What are the impacts of gas (volcanoes)?
-Can kill many people or cause them to fall unconscious
-Can poison land/soil
73
What are lahars?
-A violent type of mudflow or debris composed of pyroclastic material
-Which usually travels down valleys
74
What are the impacts of lahars?
-They can bury and destroy manmade structures like roads
-Can trap people
-Can cause severe riverbank erosion
-Can clear areas of woodland or agriculture
75
What is soil liquefaction?
-The shaking of the ground (During the earthquake) forces water to the surface
-This causes the ground to lose its strength
-Therefore buildings then sink
76
What is a positive correlation?
As one factor increases the other factor increases
77
What is a negative correlation?
As one factor increases another factor decreases
78
What is the GPD per capita in Chile?
-GPD per capita is 30 billion
79
What were the primary effects of the earthquake in the HIC (Chile)?
-Around 500 people were killed and **12,000 injured** (80,000 affected)
-**220,000 homes**, 4500 schools, 53 seaports, **56 hospitals** and other buildings were destroyed
80
What were the secondary effects of the earthquake in the HIC (Chile)?
-**1500 Km of roads** were damaged badly by **landslides** – remote communities were cut off for many days
-**A fire at a chemical plant near Santiago** – The area had to be evacuated
81
What is the earthquake management like in the HIC (Chile)?
-Chile has one of the **most effective** disaster relief infrastructures in the world
-This is due to the **rigorous building codes, evacuation simulations and preparation**
82
What was the immediate responses to the earthquake in a HIC (Chile)?
-Temporary repairs made to the important **route 5** north-south highway meant that **aid could be transported** from Santiago to affected areas
-A national appeal raised **US$60** million – enough to build **30,000 small emergency shelters**
83
What were the long term responses to the earthquake in a HIC (Chile)?
-A month after the earthquake Chile’s government launched a housing reconstruction to help nearly 200,00 homes affected
-Chile’s strong economy could be rebuilt without the need of much foreign aid
84
What is the GPD per capita in Nepal?
-The GPD per capita is 10 billion
85
What were the primary effects of the earthquake in an LIC (Nepal)?
-**9000 people died and 20,000** injured – over 8 million people were affected **(1/3 of the population)**
-**3 million people left homeless** after homes were destroyed
-**1.4 million people** needed food, water and shelter in the days and weeks after the earthquake
86
What were the secondary effects from the earthquake in an LIC (Nepal)?
-Avalanches on **Mount Everest** killed at least **19 people**
-An avalanche in **Langtang** region left **250 people missing**
-A **landslide** blocked the **Kali Gandaki River** (90 miles from Katmandu) - Many people evacuated in case of flooding
87
What was earthquake management like in an LIC (Nepal)?
-The country was poorly placed to cope with such a shock
-No warning system
-More than 50% of its population lives below the poverty line
-The geology of the floor is made of unconsolidated sediments of sand which increases the vibration of the earthquake and causes **soil liquefaction.**
88
What were the short term responses to the earthquake in an LIC (Nepal)?
-**Helicopters rescued** many people caught in avalanches on **Mount Everest** and delivered supplies to villages cut off by landslides
-**Half a million tents** needed to provide shelter for the homeless
-**Field hospitals** set up to help support overcrowded main hospitals
89
What were the long term responses to an earthquake in an LIC (Nepal)?
-**Roads repaired** and landslides cleared. Lakes formed by landslides were cleared to avoid flooding
-Thousands of homeless people to be **re-housed** and damaged homes repaired – Over **7000 schools** to be repaired
-**Stricter** controls on building repairs
90
What are the main reasons people live in hazardous regions?
-They've always lived there therefore moving means leaving jobs or families
-Volcanic soil is really fertile due to the minerals in the ash
-Volcanoes are tourist attractions meaning that people can work in the tourist industry
91
What are the methods of reducing the effects of tectonic hazards?
-Monitoring
-Prediction
-Planning
-Protection
92
How does monitoring earthquakes reduce the risk of them?
-Seismometers and lasers monitors the earth movements and can be useful in warning systems
-This will give enough warning before a large earthquake occurs
93
How does monitoring a volcano reduce the risk?
-Scientists can tell the signs of a volcanic eruption
-These signs include tiny earthquakes, escaping gas and changes in the volcano's shape
94
How does prediction of earthquakes reduce the risk?
Earthquakes cannot be reliably predicted but scientists can forecast where they may occur by monitoring movement of tectonic plates
95
How does prediction of volcanoes reduce the risk?
They can be predicted if scientists monitor them closely
96
What are the methods of protecting people from earthquakes?
-Using reinforced concrete to build buildings that absorb the earthquake's energy
-Existing buildings can be strengthened too with steel frames to reduce the likelihood of them collapsing
-**Automatic shut off switches** can turn of gas and electricity supplies in order to prevent fires
97
What are the methods to protect people from volcanic eruptions?
-Buildings can be strengthened so they're less likely to collapse under the weight of ash
-Trenches and barriers have been used to divert lava from settlements however with little success
98
What are the methods of planning in order to reduce risk of a natural event?
-Emergency services can prepare by practicing rescuing people from collapsed buildings
-People can be educated so they know what to do if a hazard occurs
-Governments can plan evacuation routes to get people out quickly and safely
99
What is the life expectancy in Chile?
79.9 years
100
What was the magnitude of the earthquake in Chile?
8.8
101
What is the literacy rate in Chile?
96.4%
102
What was the type of plate boundary the earthquake in Chile happened on?
Destructive plate margin
103
What is the life expectancy in Nepal?
70 years
104
What is the literacy rate in Nepal?
67.9%
105
What was the magnitude of the earthquake in Nepal?
7.9
106
What type of plate boundary did the earthquake in Nepal happen at?
Collision plate margin
107
Define global atmospheric circulation
The transfer of heat from the equator to the poles by movement of air
108
Why does air move?
Due to the differences in air pressure
109
Where do winds blow?
-From areas of high pressure to areas of low pressure
110
What pressure does rising air give?
Low pressure
111
What pressure does cooling air give?
High pressure
112
What is the name of the 3 cells in the earth?
-Hadley cell
-Ferrel cell
-Polar cell
113
How does air move in the cells initially?
1) The sun warms the earth at the equator causing air to rise - This creates a low pressure belt
2)As the air rises it cools and moves away from the equator
3) 30 degrees north and south of the equator the cool air sinks - Creating a high pressure belt
114
How does air move in the cells after the cool air sank 30 degrees North and south of the equator?
1) At the ground surface the cool air moves in one of two ways. Back to the equator (Trade winds) or towards the poles (Westerlies)
2) The wind curves because of the Earth's rotation - called the Coriolis effect
115
How does air move 60 degrees north and south of the equator?
1) The warmer surface winds meet colder air from the poles. The warmer air rises creating low pressure
2) Some of the air moves back towards the equator and the rest moves towards the poles
3) At the poles the cool air sinks - creating high pressure
4) The high pressure air is then drawn back towards the equator
116
How does air move in the cells? (Full version)
1) The sun warms the earth at the equator causing air to rise - This creates a low pressure belt
2)As the air rises it cools and moves away from the equator
3) 30 degrees north and south of the equator the cool air sinks - Creating a high pressure belt
4) At the ground surface the cool air moves in one of two ways. Back to the equator (Trade winds) or towards the poles (Westerlies)
5) The wind curves because of the Earth's rotation - called the Coriolis effect
6) The warmer surface winds meet colder air from the poles. The warmer air rises creating low pressure
7) Some of the air moves back towards the equator and the rest moves towards the poles
8) At the poles the cool air sinks - creating high pressure
9) The high pressure air is then drawn back towards the equator
117
What is the Coriolis effect?
When the trade winds/Westerlies curve because of the Earth's rotation
118
What are the trade winds?
Winds that move back towards the equator
119
What are the Westerlies?
Winds that move towards the poles
120
What is weather and climate like at the equator?
-The sun is directly overhead
-Therefore the Earth's surface receives alot of solar radiation, so it's hot
-Warm, moist air rises and forms clouds so it rains alot
121
What is weather and climate like at 30 degrees north and south of the equator?
-When the air reaches 30 degrees north and south it has released most of its moisture as rain
-The dry air means there are few clouds and little rainfall
-Therefore deserts are often found at this lattitude
122
What is weather and climate like at 60 degrees north and south?
-It is a low pressure zone
-Warm air rising brings lots of cloud cover and rainfall
-These are often as low pressure systems carried from the Atlantic by westerly winds
123
What is the order in the cells of the Earth?
Hadley cell, Ferrel cell, Polar cell
124
Where do tropical storms develop?
Between 5 and 30 degrees north and south of the equator
125
What are the necessary conditions for tropical storms to develop?
-When sea temperature is 27 degrees C or higher
-Wind shear between higher and lower parts of the atmosphere is low
126
What is wind shear?
The difference in wind speed
127
How do tropical storms develop?
1) The warm surface water evaporates, rises and condenses into clouds. This releases a huge amount of energy producing powerful storms
2) The rising air creates low pressure which increases surface winds. Low wind shear prevents clouds breaking up as they rise so storms stay in tact
3) Easterly winds near the equator move tropical storms to the west
4) The storms spin because of the Coriolis effect
5) As the storm moves over the ocean, the energy from the warm water strengthens the storm so wind speeds increase
128
What happens to tropical storms as they move over land or cooler air?
Tropical storms lose strength as the move over land or cooler water as the energy supply from the warm water is cut off
129
What time of year do the majority of tropical storms occur in the northern hemisphere?
August to October
130
What time of year do the majority of tropical storms occur in the Southern hemisphere?
December to April
131
What are key facts about tropical storms?
-They last 7-14 days
-They are circular in shape
-They're hundreds of Km wide
-In the **northern** hemisphere they spin **anticlockwise**
-In the **southern** hemisphere they spin **clockwise**
132
What are the key features of a tropical storm?
-They eye
-The eyewall
-The edges of the storm
133
What are the features of the eye of a tropical storm?
-They eye is the centre of a tropical storm and is caused by **descending air**
-There is very **low pressure**
-Light winds
-And a high temperature
134
What are the features of an eyewall of a tropical storm?
-They eye is surrounded by an eyewall
-There is **spiraling rising air**
-**Very strong** winds
-Storm clouds
-Torrential rain
-**low** temperature
135
What are the features of the edge of a tropical storm?
-The wind speeds **fall**
-The clouds become **scattered**
-The clouds become **smaller**
-Rain becomes **less intense**
-Temperature **increases**
136
Facts about typhoon Haiyan
-Happened on 8th November 2013
-**Tacloban and Cebu** were the worst affected areas with up to **280mm** of rainfall and winds reaching **314 km/h**
-Storm surge with waves of up to 2.3m combined with a high tide meant Tacloban was hit by **waves up to 5m**
137
What were the primary effects of Typhoon Haiyan?
-**1.9 million** people homeless
-The cost of damage was at approximately **$13 million**
-Strong winds **damaged electricity** lines and water supplies were **contaminated by salt water** from the **storm surge**
138
What were the secondary effects of Typhoon Haiyan?
-Flooding triggered several **landslides** which blocked road and **delayed arrival of aid**
-**5.6 million** workers lost their jobs after businesses and agricultural land were **destroyed**
-The **lack of clean water** caused an outbreak of **diseases such as dysentery**
139
What were the immediate responses to Typhoon Haiyan?
-The Philippines meteorological agency **(PAGASA) broadcast warnings** which led to the **evacuation of 800,000 people** - however some died and evacuation centres flooded
-The Philippines declared a **state of emergency** which led to many charities offering **aid** in the form of **food, clean water and shelter**
-Plan international constructed **pit latrines** for **100,000 people** to help prevent the spread of disease
140
What were the long term responses to Typhoon Haiyan?
-The **UN** appealed for over **$300 million** to help fund rebuilding and relief
-Charities built new **storm resistant houses** for people who lost their homes
-The Philippines' **tourism** board **encouraged people to visit** the country after the storm by emphasising that most areas were unaffected and that most money would help with the rebuilding
141
How is climate change affecting the frequency of tropical storms?
-Oceans will stay at 27 degrees or higher for longer each year so there is a longer period where tropical storms can form
142
How will climate change affect the distribution of tropical storms?
-As the average ocean temperature rises more of the world's oceans could be above 27 degrees - this may mean that tropical storms can form in areas that haven't experienced them before
143
How will climate change affect the intensity of tropical storms?
-Higher sea surface temperatures are likely to result in **more evaporation** and increased cloud formation so **more energy** is released - This could mean storms become **more powerful**
144
What will climate change affect about tropical storms?
-intensity
-Frequency
-Distribution
145
What are the methods of reducing the effects of tropical storms?
-Planning
-Protection
-Prediction and monitoring
146
What are the methods of prediction and monitoring of tropical storms?
-Storms can be monitored using radar, **satellites and aircraft** - Computer models can then be used to calculate the storm's predicted path
-Predicting where and when a tropical storm will happen will give people time to evacuate and protect their homes and businesses
147
What are the methods of planning to reduce the effect of tropical storms?
-Future developments like new houses can avoid high risk areas like low-lying coastal zones
-Governments can plan evacuation routes to ensure people can evacuate quickly
-Emergency services can prepare for disasters by practicing rescuing people from flooded areas
148
What are the methods of protection to reduce the effect of tropical storms?
-Buildings can be designed to withstand tropical storms - buildings can also be put on stilts so they're safe from floodwater
-Flood defenses can be built alongside rivers and coasts (Levees and sea walls)
149
What did the Philippines do to predict and monitor tropical storms?
-During Typhoon Haiyan predicting the storm's path helped authorities decide which areas needed to be evacuated
150
What did the Philippines do to plan and reduce the effect of tropical storms?
-After Typhoon Haiyan volunteers started rescue simulations so they were better prepared for future storms
151
What did the Philippines do in order to protect and reduce the effect of tropical storms?
Mangrove forests are being planted in order to act as a natural flood defense
152
What are the different weather hazards the UK experiances?
-Strong winds
-Heavy rainfall
-Snow and ice
-Drought
-Thunderstorms
-Heat waves
153
What are the impacts of strong winds?
-Can damage properties and transport
-Uprooted trees and debris can injure or kill people
154
What are the impacts of heavy rainfall?
-Too much rain can cause flooding which can damage homes, disrupt transport networks and drown people
-Recovering from flooding can cost millions of pounds
155
What are the impacts of snow and ice?
-Snow and ice can cause injuries due to slipping and deaths due to cold
-Schools and businesses have to shut and disruption to travel can have economic impacts
156
What are the impacts of droughts?
-Water supplies running low causes economic impacts like crop failures
-Rules to conserve water have to be introduced
157
What are the impacts of thunderstorms?
-Heavy rain, strong winds and lightning can all occur during thunderstorms
-Lightning can cause fires which can damage property, and the environment and even kill people
158
What are the impacts of heat waves?
-During long periods of **hot weather pollution** builds up in the air - This can cause heat exhaustion and **breathing difficulties which can kill people**
-Disruption to transport from rails buckling or roads melting can have economic impacts
-BUT the **tourism industry** may benefit from better weather
159
How is the UK weather changing?
-The UK's 10 warmest years have occurred since 1990 and 2018 was the joint hottest summer on record
-Extreme cold has also become more frequent and December 2010 was the coldest month for over 100 years
160
How is the rainfall in the UK changing?
-More rainfall records were broken between 2010 and 2014 than in any decade on record
-Major flooding events have become more frequent over the past 10 years - December 2015 was the wettest month ever recorded
161
What happened in Somerset in Winter 2013-2014?
-From December (2013) to February (2014) Somerset experienced **3 times** the average amount of rainfall for those months
-Rain fell on **saturated** ground and coincided with **high tides and storm surges**
-This caused **extensive flooding** especially in **low-lying areas**
-Also the river's **weren't dredged for 20 years** so they had **limited capacity**
162
What were the social impacts of the Somerset floods?
-More than **600 homes** flooded - people had to evacuate
-Insurance prices soared
-villages like **Muchelney** were cut off
163
What are the environmental impacts of the Somerset floods?
-**11,500** hectares of land flooded which destroyed many crops
-Standing water made the ground **toxic and unproductive** - Loss of nutrients and damage decreased overall fertility of the land
-Tonnes of **mud and debris** left by floods which **damaged vegetation**
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What are the economic impacts of the Somerset floods?
-Total cost was over **£80 million**
-Local companies lost more than **£1.2 million** in business
-Loss of tourism cost the country **£200 million**
165
Which flood management strategies were implemented BEFORE the flood in Somerset happened?
-**Flood warning systems** - these gave people time to prepare and people found **emergency accommodation**
-People used **sand bags and flood boards** to limit flood damage to homes
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Which flood management strategies were implemented AFTER the flood in Somerset happened?
-**£100 million** will be spent on:
-Building a **tidal barrage** at Bridgewater
-Turning temporary pumping stations into **permanent** ones
-Regular **dredging** of the Rivers Parrat and Tone
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What is dredging?
Clearing a river of sediment
168
What is the Quaternary period?
The most recent geological time period spanning from 2.6 million years ago to now
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What was the climate like before the Quaternary period?
Warmer and quite stable
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How has global temperature shifted in the Quaternary peiod?
-It has shifted from **cold glacial** periods (which lasted around 100,000 years) and **warmer interglacial** periods which last for around 10,000 years
171
What is global warming?
The sharp rise in global temperatures over the last century - A type of climate change
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What is the evidence for climate change?
-Ice and sediment cores
-Tree rings
-Pollen analysis
-Temperature records
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How do ice and sediment cores provide evidence for climate change?
-Ice sheets are made up of layers of ice (One layer formed each year)
-Scientists **drill** into these sheets to get long cores of ice
-By analysing the **gases trapped in in the layers** of gas they can tell the temperature each year
-The **remains in organisms** found in cores taken from ocean sediments can also be analysed
-These can extend the **temperature record back at least 5 million years**
174
How do tree rings provide evidence for climate change?
-As a tree grows it forms a new ring each year
-In **warm and wet** conditions these rings are **thicker**
-Scientists take cores and count tree rings to find the age of the tree. The thickness shows what the climate was like
-Tree rings are a reliable source of evidence for climate change for the past **10,000 years**
175
How does pollen analysis provide evidence for climate change?
-Pollen from plants is preserved in sediment at the bottom of lakes
-Scientists can identify and date the preserved pollen to show **which species were living at that time**
-Scientists know the **conditions that plants live in now** so preserved pollen from similar pants show that climate conditions were similar
176
How do temperature records provide evidence for climate change?
-Global temperatures have been measured using thermometers which provides a reliable short term record of climate change
-Historical records like harvest dates or newspaper weather records can extend the record of climate change further back
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What are the natural factors that cause climate change?
-Orbital changes
-Solar output
-Volcanic activities
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How do orbital change contribute to climate change?
-Orbital changed affect how much solar radiation the earth receives - more energy means more warming
179
What are the three orbital variations in the earth?
-Stretch
-Tilt
-Wobble
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What is the stretch earth orbit?
-The Earth's orbit around the sun varies from circular to elliptical
-Called Eccentricity
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What is the tilt orbit?
-The Earth's axis is tilted at an angle as it orbits the sun
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What is the wobble orbit?
The Earth's axis wobbles like a spinning top (Precession)
183
How does volcanic activity lead to climate change?
-Major volcanic eruptions **eject large quantities of material** into the atmosphere
-Some of these particles **reflect the sun's rays** back out to space so the Earth's surface cools
-Volcanic activity causes short term changes in climate
184
How does solar output contribute to climate change?
-The sun's energy output isn't constant - it changed in short cycles of about 11 years
-Reduced solar output means that the Earth's climate is cooler in some areas
-Solar output isn't thought to have a major effect on global climate change
185
What are the human factors that contribute to climate change?
-Burning fossil fuels
-Cement production
-Farming
-Deforestation
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What is the greenhouse effect?
-When greenhouse gases (like carbon dioxide) absorb outgoing heat from the earth
187
What happens when the greenhouse gas levels increase?
More energy is trapped and the planet warms up even more
188
How does burning fossil fuels contribute to climate change?
-CO2 is released into the atmosphere when fossil fuels are burnt
189
How does cement production contribute to climate change?
-Cement is made from limestone which contains carbon
-When cement is produced lots of CO2 is released into the atmosphere
190
How does farming contribute to climate change?
-Farming livestock produces alot of methane
-Rice paddies contribute as flooded fields emit methane
191
How does deforestation contribute to climate change?
-Plants remove CO2 from the atmosphere and convert it into organic matter
-When trees are cut down they stop taking in CO2
-CO2 is also released into the atmosphere when trees are burnt as fuel
192
How does climate change affect the enviroment
-Warmer temperatures cause glaciers to shrink and ice sheets to melt. This causes sea levels to rise as water stored on land is returned to oceans
-Sea ice shrinks which leads to loss of habitat
-Rising sea means low-lying and coastal areas will flood ore regularly - Coastal erosion will also increase and some areas will be submerged for more habitats lost
-Distribution and quantity of some species is changing and biodiversity decreases
-Species live at higher latitudes due to warming temperatures
-Some habitats being damaged causes species to become extinct
-Precipitation patterns are changing
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How does climate change affect humans?
-Deaths due to heat have increased and deaths due to cold have increased
-Low-lying coastal areas could be lost to the sea or flood so often they become uninhabitable - This leads to overcrowding and migration
-Some areas are struggling with water supply due to changing rainfall patterns there is less water availability
-Some places there is a lower yield in crops because of the higher temperature but in some places there is a higher yield in crops
194
What are the methods of reducing the greenhouse gases in the atmosphere?
-Carbon capture
-Planting trees
-Alternative energy production
-International agreements
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How does carbon capture reduce the amount of greenhouse gas in the atmosphere?
-Carbon capture and storage (CCS) is designed to reduce emissions from power stations burning fuels
-CCS involves capturing CO2 and transporting it to safe places where it can be stored (Deep underground)
196
How does planting trees reduce the amount of grenehouse gases in the atmosphere?
Planting more trees increases amount of CO2 that is absorbed from the atmosphere through photosynthesis
197
How does alternative energy production reduce the amount of greenhouse gases in the atmoshpere?
-Replacing fossil fuels with nuclear or renewable energy can help reduce greenhouse gas emissions
-In the UK offshore wind farms are being built and several wave, tidal and nuclear power projects have been planned
198
How do international agreements reduce the amount of greenhouse gases in the atmosphere?
-The **Paris agreement** aims to reduce greenhouse gas emissions and **limit global warming** - it encourages developed countries to help developing countries put mitigation strategies into place
-Each country has submitted a pledge which indicates how much they will try to reduce their greenhouse gas emissions
199
How have people adapted to climate change?
-Changing agricultural systems
-Managing water supply
-Coping with rising sea levels
200
How have people adapted to climate change by changing agricultural systems?
-**Changing rainfall patterns and high temperatures** will affect productivity of existing systems
-It may be necessary to **plant new crop types** that are more suited to climate conditions
-In some areas **biotechnology** is used to create crop varieties which are more resistant to extreme weather events
201
How is managing water supply a method of adapting to climate change?
-**Dry areas** are predicted to **get drier** leading to more water shortages - So people need to use water more **efficiently**
-**Water meters** can be installed in homes to **discourage excessive water use**
-Rainwater and waste water can be collected and **recycled**
202
How is coping with rising sea levels a method of adapting to climate change?
-Sea levels are predicted to rise which could flood many islands
-Better **flood warning systems** are being put in place and physical defences such as **flood barriers** are being built
-In areas that can't afford flood defences people are building raised **flood shelters** and building houses on embankments
