Challenge Of Natural Hazards Flashcards
+ Case Study L'Aquila/ Nepal/ Irma/ Beast from the East
What is a natural hazard
Natural hazards are extreme natural events that can cause loss of life, extreme damage to property and disrupt human activities.
Name 3 types of hazards and examples.
-Atmospheric.. Hurricanes
-Tectonic.. Earthquakes
-Geological.. Landslides
List the 8 factors affecting hazard risk
-Time
-Magnitude
-Natural Factors
-Level of development
-Education
-Frequency
-Management
-Population Density
Name 4 layers of the earth
Crust, Mantle, Outer Core, Inner Core.
What state is the crust
Solid
What state is the mantle
Liquid
What state is the Outer Core
Liquid
What state is the Inner Core
Solid
What is outer and inner core mostly made of
Iron and Nickel
What is the widest layer of the earth
Mantle
How are convection currents made (EQ)
1) Radioactive decay of some of the elements in the core and mantle generate a lot of heat.
2) When lower parts of the magma heat up they become less dense and slowly rise.
3) As they move towards the top they cool down, become more dense and slowly sink.
4) These circular movements of semi-molten rock are convection currents.
5) Convection currents create a drag on the base of the tectonic plates and this causes them to move.
What are four types of plate boundaries
-Destructive
-Constructive
-Conservative
-Collision
What happens at a destructive margin
As the plates collide, the denser oceanic plate subducts beneath the continental plate. The friction as the plate sinks causes the mantle to melt to magma causing pressure to build. The magma escapes through weaknesses in rock forming composite volcanoes. Causes earthquakes and volcanoes.
What happens at a constructive margin
Two plates move apart causing new magma to reach the surface through the gap to form shield volcanoes. Can cause earthquakes.
What happens at a conservative margin
Two plates move past each other side by side at different speeds. Pressure is built from the friction causing earthquakes when the energy is released.
What happens at a collision margin
Two continental plates collide, where neither can sink so the land buckles upwards and forms fold mountains. Causes earthquakes.
What is the focus in an earthquake
The point of which pressure is released.
What are seismic waves in earthquakes
Energy waves that travel out from the focus
What is the epicentre in earthquakes
The point directly above the focus, where seismic waves reach first.
What measures the magnitude
The Richter Scale
How do earthquakes happen (EQ
When two plates become lockes causing friction to build up which causing pressure to build. The pressure is eventually released triggering the plates to move into a new position. This movement causes energy in the form of seismic waves to travel from the focus towards the epicentre. As a result, the crust vibrates triggering an earthquake.
What are the two ways of earthquake management
- Predicting
- Prevention
List ways of predicting earthquakes
-Satellite surveying
-Laser Reflection
-Radon gas sensor (Radon gas is released when plates move)
-Seismometer
-Water table level
-Seismic records to predict next event.
List ways of preventing damage from earthquakes
-Build earthquake resistant buildings
-Raise public awareness
-Improve earthquake prediction.
What are features of earthquake resistant buildings (EQ)
-Several emergency staircases and exits to speed up evacuation.
- Deep foundations into solid rock.
-Shock absorbers in foundations to absorb seismic waves
- Roof covering area outside the building to prevent pedestrians being showered with broken glass
-Weights on roof to counterbalance shaking
-Cross braing to provide extra support to strong steel frames.
LIC Case Study: Context of Nepal Earthquake
-On 25th April 2015
-7.8 magnitude
-In Barpak, 80 km NW of the capital Kathmandu
-Eurasian plate and Indian Plate at a collision plate margin
-In the Himalayas
LIC Case Study: What are the primary effects of earthquake in Nepal
-8841 died
-16800 injured
-over 1 million homeless
-modern buildings collapsed due to lack of building regulations
-26 hospitals and 50% of schools destroyed
-352 aftershocks.
LIC Case Study: What are the secondary effects of earthquake in Nepal
-Triggered an avalanche on Mt Everest. 19 died.
- Tourism/Employment
/Income Shrink
-2/3 of population depend on rice farming for food, but rice seed was ruined in rubble causing food shortage and income loss.
LIC Case Study: What are the immediate responses of earthquake in Nepal
-Temporary shelters, 225,000 people provided with tents from Red Cross
-UK raised $126 million for emergency aid by Sept 2015.
-UN and WHO provided medical supplies to worst areas as risk of waterborne diseases increased from monsoon seasons
LIC Case Study: What are the long term responses of earthquake in Nepal
-$274 million of aid
-Heritage sites reopened to attract sites
-Mt Everest reopened and rerouted, climbing permits extended
-Recovery phase after 6 months to expand crop production.
HIC Case Study: Context of L’Aquila Earthquake
-On 6th April 2009
-6.3 magnitude
-Epicentre 7 km NW of L’Aquila
-Eurasian plate and African Plate at a destructive plate margin
-In the Apennine Mountains
HIC Case Study: What are the primary effects of earthquake in L’Aquila
-308 died
-1500 injured
-67500 homeless
-Monuments and cultural buildings destroyed
-Buildings for university destroyed
HIC Case Study: What are the secondary effects of earthquake in L’Aquila
-Aftershocks triggering landslides and rockfalls
-Landslides and mudflow burst main water supply
-Lack of housing causes house prices and rents to increase
-Number of students at uni decrease
-City’s central business cordoned off due to unsafe buildings, where some ‘red zones still exist- causes a decrease in amount of business tourism and income
HIC Case Study: What are the immediate responses of earthquake in L’Aquila
-Hotels provided shelter for 10,000+ people
-40000 tents lent out and train carriages used as shelter
-Prime Minister offered some of his homes as shelter
-Italian Red Cross searching for survivors within hour
-Mortgages and bills suspended (free)
- British Red Cross raised $171,000 in support
HIC Case Study: What are the long term responses of earthquake in L’Aquila
-Torch lit procession for remembrance
-Residents didn’t pay taxes until 2010
-Students had free public transport, discounts and exempt uni fees for 3 years
-Several years to rebuild homes and 15 years for historic centres
-6 scientists blamed for not predicting earthquake and convicted for manslaughter- they had to pay several million euros in damages and spend 6 years in prison.
List Volcanic Hazards
-Ash Cloud
-Gas
-Lahar
-Pyroclastic Flow
-Volcanic Bomb
What is an ash cloud
Small pieces of pulverised rock and glass which are thrown into the atmosphere
What is the gases of volcanoes
Sulphur dioxide, water vapour and carbon dioxide
What is a lahar
A volcanic mudflow which usually runs down a valley side
What is pyroclastic flow
A fast moving current of super-heated gas and ash
What is a volcanic bomb
A thick (viscous) lava fragment that is ehected from the volcano
What warnings can be detected for volcanoes
-Small earthquakes are caused
-Temperatures around the volcano rise
-Release of gases from volcano
What can be used to monitor volcanoes
-Seismometers
-Thermal imaging and satellite cameras to detect heat
-Gas samples and chemical sensors to meausre sulphur levels
How can you prepare for a volcano
-Create an excluive zone around the volcano
-Be ready and able to evacuate residents
-Have emergency supply of basic provisions
-Trained emergency services and a good communication system
What are the three cells in GAC
-Hadley Cell
-Ferrel Cell
-Polar Cell
How is low pressure caused
-By hot air rising
-Causes stormy,cloudy weather
How is high pressure caused
-By cold air sinking
-Causes clear and calm weather
What is a tropical storm
A very powerful, low-pressure weather system.
What measures tropical storms
Saffir-Simpson Scale
What is the formation of tropical storms (EQ)
1) The sun’s rays heats large areas of oceans and causes warm, moist air to rise over the particular spot.
2)Once the temperature reaches 27oC , the rising air leads to a low pressure which turns into a thunderstorm. The air is sucked in from the trade winds.
3)With trade winds blowing the opposite direction and coriolis effect, the thunderstorm will eventually start to spin.
4)When the storm is spinning faster than 74mph, a tropical storm is officially born.
5)With the tropical storm growing in power, more cool air sinks in the centre of storm, creating calm and clear conditions called the eye of the storm.
6)When the tropical storm hits land, it loses its energy source and it begins to lose strength until it eventually blows itself out.
Why are tropical storms increasing
Global warming has an impact on the frquency and strength of the storms which may be due to an increase in ocean temperatures.
Case Study: Context of Hurricane Irma
-Category 5 Hurricane
-From 30/08/2017-16/09/2017
-Formed over the Atlantic Ocean
-Affected a number of Islands in Atlantic and Caribbean Sea, hit Barbuda before reaching Florida
-Increased in power over warmer seas in Gulf of Mexico.
Case Study: What are the primary effects of Hurricane Irma
-130 people died
-Storm surge of 10-15 ft
-Homes/businesses destroyed
-Loss of electric supply
-Coastal and marine habitats destroyed
-Roads blocked from fallen trees
Case Study: What are the secondary effects of Hurricane Irma
-Sewage overflow
-Disease risk
-Destroyed Habitats
-Food Shortages
-Disney World Closed : $30 mil lost in a day
-$64bn repairs and damages
Case Study: What are the immediate responses of Hurricane Irma
-Florida evacuation of 7mil
-Food parcels
-Temporary shelters in sports centres
-Army help e.g RAF aid
-Red Cross
-International Fundraising
Case Study: What are the long term responses of Hurricane Irma
-Attract businesses and tourists
-Better flood protection and warning systems
-FEMA emergency funds
-Long term rebuilding
-Restore full electricity
How do you manage tropical storms
-Forecast e.g satellites and hurricane hunters
-Prepare e.g emergency kits, education
-Act e.g evacuation and building defense
List 5 types of UK weather hazards
-Thunderstorms
-Prolonged Rainfall
-Drought/Extreme Heat
-Heavy Snow/Extreme Cold
-Strong Winds
List the 5 types of air masses for UK
-Tropical Maritime
-Polar Maritime
-Arctic Maritime
-Polar Continental
-Tropical Continental
Case Study: Context of Beast From The East
-Extreme Weather Event
-Heavy Snow
-Extreme Cold
-On 27th February 2018- 1st March 2018
Case Study: What are the primary effects of Beast From The East
-10 people killed
-Icy roads
-Roads blocked
-15-20cm of snow fell for days
- Rural areas lows of -12oC
-Waves batter coastlines
-Flood warnings
-Hundreds stranded for up to 36hrs on M80 motorway
Case Study: What are the secondary effects of Beast From The East
-Shops starting to run out of produce
-Thousands of schools and shops forced to close down
-British airways cancelled huge number of short-haul flights
-Road accidents - estimated 8000
-Rural towns/villages cut off
-NHS cancelled all non-urgent operations and clinics.
-UK issued with gas deficit-homes without power
Case Study: What are the immediate responses of Beast From The East
-Advised not to travel
-RAF deployed to rescue drivers and drive NHS workers
-Greggs delivery driver hands out cakes to stranded drivers
-Community centres open for homeless people
-Met office issues red warning
-Snow ploughs, gritters and tractors to clear snow
-Rail stations and networks closed
Case Study: What are the long term responses of Beast From The East
-Environmental Action Plans
-NHS Winter plan for suture extreme weather events
What are the evidences for climate change from quaternary period to present
-Ice and Sediment e.g gas trapped between ice sheets and remains of organisms found in ocean sediment from millions of years ago
-Temperture Records
-Tree Rings e.g New rings each year, thicker rings show warm,wet conditions.
-Pollen Analysis e.g Pollen preserved in sediment can compare to conditions the plant must have lived in
-Sea Level Changes
What are the natural causes of climate change
-Sunspot Theory: dark spots on sun causing lots more solar energy fired at earth increasing temperature
-Orbital Theory:The change in orbit from cirular to elliptical affects amount of solar radiation received
-Eruption Theory: Big volcanic eruptions releasing ash and sulphur dioxide gas creates a blanket around the world as high levl winds spread the products. The blanket reflects sunlight back to space and lowers average temp of earth.
What are the human causes of climate change
-Natural Greenhouse Effect: Less heat escapes into space and is reflected back to earth.
-Agriculture: Methane released from rice cultivation and cattle. Nitrous oxide released from fertilizer
-Fossil Fuels
-Deforestation
What is effected by climate change
-Agriculture
-Habitat Loss
-Oceans
-Extreme Weather
What is mitigation
Means to reduce or prevent the effects of something
What are mitigations of climate change
-Afforestation
-Carbon Capture Storage
-Renewable Energy
-International Agreements
What are adaptions to climate change
-Changing agricultural systems e.g plant new crops
-Managing water supply e.g water meters
-Managing Flood Risk e.g LICs build homes on stilts and HICs invest in sea defences
