Natural Hazards Flashcards
What is a destructive plate boundary?
Plated move together, oceanic plate sub ducted by continental plate.
Volcano
Earthquake
Constructive plate boundary:
Plates move apart, magma fills gap, oceanic plate
Volcano
Earthquake
Conservative plate boundary
Past one another
Friction
Earthquake
Structure of earth
Inner core
Outer core
Mantle
Crust
What is convection current?
Hot current rises from core towards crust but then cools as it looses heat and sinks back towards core in a circular motion.
Describe the global distribution of earthquakes and volcanos
Usually occur on plate boundarys
Mid Atlantic ridge
Pacific ring of fire
What is an earthquake
Vibrations of the earths crust that cause shaking at the surface
Friction builds up
Energy is released as shock
Point where it happens is called epicentre
What is a volcano
Explosion involving magma coming up through the earths surface
What are the two types of volcanos
Shield and composite
What was the magnitude of the Nepal earthquake
7.9
Magnitude of l’aquila earthquake
6.3
Deaths from Nepal earthquake
9000
Deaths from l’aquila earthquake
300
Homeless from Nepal earthquake
1 million
Homeless from l’aquila earthquake
70,000
Primary effects of Nepal earthquakes
350 aftershocks
26 hospitals destroyed
50% schools destroyed
Primary effects of l’aquila earthquakes
$11,000 worth of damage
Secondary effects of Nepal earthquake
Avalanche on Mount Everest
19 died
Secondary effects of l’aquila earthquake
Number of students at uni in the area decreased, causing loss in economy
Primary responses to Nepal earthquake
Facebook safety feature
L’aquila earthquake primary responses
40,000 tents given out and 10,000 hotel rooms provided for free
Secondary responses of Nepal earthquake
Government carried out post disaster needs assessment
Secondary responses to l’aquila earthquake
Residents didn’t have to pay tax in 2010
Why can earthquakes be different in different places?
Magnitude
Time of year
Day and time
Population density
Why would a person continue to live in a tectonically active area?
Some settlements have grown into enormous cities so would be difficult to move
Some places are well prepared for hazards so people feel safe
Good job and way of life may keep you in the danger zone
How can we reduce the risks of a tectonic hazard?
Monitoring when it will happen
Planning what to do when it happens
Protecting people and buildings against the hazards
Predicting when it will happen
What is the order of the air cells from the equator?
Hadley
Ferrel
Polar
Where are the areas of low pressure?
Equator and then alternates between cells outwards
Why is heat more concentrated at the equator?
There is less surface area for the heat to spread Across
How are clouds formed?
When warm moist air cools and condenses
Where do tropical storms happen?
5-20 degrees north and south of the equator
What temp does the ocean need to be for a storm to form
26.5
What are the six steps of a tropical storm forming
- Sun warms ocean up to 26.5 degrees and causes evaporation
- Moist warm air rises causing low pressure
- air cools and condenses and draws in more moisture from the air causing strong winds
- Coriolis effect makes air spin upwards and creates eye of storm
- Air forms large cumulonimbus clouds which make heavy rainfall
- Air rushes from outside of storm to centre creating stronger winds
What are the conditions at the eye wall?
Extremely heavy rain
Conditions at eye of the storm
Very calm
Conditions outside eye wall of storm
Heavy rain
Thunder
How does climate change effect the distribution of tropical storms
Patterns of sea surface temperature
Don’t form in south Atlantic
How does climate change affect the frequency of tropical storms
Frequency may decrease in the futureh
How might climate change effect the intensity of tropical storms
Sea surface temperature rise so easier for storms to form at higher rates
When was typhoon Haiyan
November 2013
What category storm was typhoon Haiyan
5
How many people died from Haiyan
6,300
How many were homeless from Haiyan
600,000
What were the secondary effects of typhoon Haiyan
6million lost main source of income
Power supplies cut off for a month
Looting and violence in tacloban
Immediate responses to typhoon Haiyan
1200 evacuation shelters set up
Field hospitals
Long term responses to typhoon Haiyan
Thousands of new homes built away from flood prone areas
Oxfam replaced damaged fishing boats
How can a tropical storm be monitored
Satellites can be sent to investigate cloud cover and precipitation
How can we be protected against tropical storms
Furniture can be strapped to the floor
Shutters added to Windows
Flood walls reduce impacts of storm surges
How can we plan for a tropical storm
Ensure vehicles have fuel for evacuation
Practice evacuation drills with family
Emergency electricity generators
What are the main weather hazards for the uk?
Extreme cold
Extreme heat and drought
Storms
Flooding
Why does the uk get extreme cold
Arctic air brings snow and cold conditions
What are the effects of extreme cold in the uk
Problems for farmers
Schools closed
How does the uk manage extreme cold
Councils are responsible for clearing roads
Charity’s raise awareness of elderly people needing help
Why does the uk get extreme heat and drought
Hot and sunny air masses and weather from the south
What are the effects of extreme heat and drought in the uk
People die and become ill from dehydration
How can the uk manage extreme heat and drought
Hose pipe ban
Example of extreme cold in the uk
December 2009 snowstorm
Example of extreme heat and drought in uk
Heatwave in 2003
Why does the uk get storms
Atlantic air
Following period of hot weather
Effects of storms in uk
Flash flooding
Lightning
How does the uk manage storms
Trains and planes cancelled
Social media alerts
Why does the uk get flooding
Prolonged rainfall
What are the effects of flooding in the uk
River floods
Damage to properties
How does the uk manage floods
Environmental agency measures ground moisture
Example of uk storm
2014 London electrical storm
Example of uk floods
Bascastle flash flood 2004
WHen were the Somerset floods
December 2013
How much rainfall occurred during the Somerset floods
350mm in two months
What were the effects of the Somerset floods
600 houses flooded
1000 livestock evacuated
Local roads cut off
Floodwater heaving contaminated with chemicals and sewage
Immediate responses of Somerset floods
Villagers used boats to go shopping and go to school
Long term responses of Somerset floods
8km of rivers were finally dredged in 2014
Road levels have been raised
What is the recent evidence for climate change
Ice cores- rings with co2
Retreating glaciers - change in response to climate change
Tree rings - thickness in rings records climate
What are the milankovitch cycles
Eccentricity / orbit
Axial tilt
Precession / wobble
What solar activity effects climate change
Sun spots
What volcanic activity effects climate change
Volcanic ash forms layer that blocks out sunlight
How does the greenhouse effect work
Some solar radiation is effected by Earth and atmosphere
Some goes straight to earth
Some bounces off earth and then off atmosphere and then back to earth
What are the sources of greenhouse gases
Burning fossil fuels for transport heating and manufacturing
Cows produce methane
Population growth
Deforestation gets rid of carbon sinks
How can we manage climate change
Use alternate sources of energy
- renewable sources
Planting trees
- act as carbon sinks
Carbon capture
Removes carbon from atmosphere and stores underground
International agreements.
Eg Paris agreementsHow do we adapt to climate change?
Agriculture
- educate farmers in water harvesting
Managing water supply
Example of a destructive plate margin
Pacific plate and Eurasian plate
Example of constructive plate margin
North American plate and Eurasian plate
Example of conservative plate margin
Pacific plate and North American plate
Example of collision plate margin
Indo Australian plate and Eurasian plate
