Hazards Flashcards
Layers of the Earth
Inner core, outer core, mantle, crust
Epicentre
The point on the earth’s surface where earthquakes are at their most powerful
Characteristics of oceanic crust
Dense, newer, thinner
Characteristics of continental crust
Less dense, older, thicker
Constructive boundaries
Plate boundaries which move apart from each other and often result in the formation of mid-ocean ridges
Modified Mercalli Scale
Measures an earthquake’s intensity based on the observed effects of people and structures
Shield volcano
A type of volcano that is low and wide with a gentle slope. They are found at constructive plate boundaries
Composite volcano
A cone shaped volcano built from many layers of lava and ash. They are found at destructive plate boundaries
Focus
the place inside Earth’s crust where an earthquake originates. Energy is released here
Feature formed at a collision plate boundary
Fold mountains
Features formed at a convergent (destructive) plate boundary
Deep ocean trenches, island arcs, volcanoes, earthquakes
Mid-oceanic ridge location
Divergent/constructive plate boundaries
Richter scale
Measures an earthquake’s magnitude based on ground shaking using a seismometer
Range: 2.4 or less - 8.0
Moment magnitude scale
Measures the total energy released by an earthquake
Volcanic Explosivity Index
Measures the intensity of volcanic eruptions on a logarithmic scale of 1-8
What type of waves are produced when an earthquake occurs?
Seismic waves
Where do tropical storms take place?
Between the Tropics of Cancer and Capricorn
Eye
The centre of a tropical storm
Low pressure
Wet weather
High pressure
Dry weather
Hurricane
Tropical storm in the Americas
Tropical storm formation requirements
- Low pressure weather systems
- Warm seas over 26˚
- 8-20˚N of the equator where trade winds converge
- In the summer and autumn where sea temp is highest
Coriolis effect
The process that causes tropical cyclones to rotate.
Northern Hemisphere = anticlockwise
Southern Hemisphere = clockwise
Saffir-Simpson scale
A 1-5 rating based only on a hurricane’s maximum sustained wind speed
Economic benefits of living close to volcanoes
Tourism, fertile soils
Short-term environmental impacts of tropical storms
Landslides, soil erosion, storm surge, flooding
How many people were displaced by Typhoon Haiyan?
600,000
Primary impact
A direct impact immediately caused by the hazard
Secondary impact
A knock-on effect of a primary impact (indirect)
Why do people choose to live near a volcano?
- Fertile soil
- Tourism
- Geothermal energy
- Beautiful landscape
- Where their family live
- Unaware of the risks
Why do people choose to live near an earthquake?
- Geothermal energy
- Believe it won’t happen to them
- Earthquake proof buildings make people feel safe
- Minerals
Social reasons why people chose to live in hazardous environments
- Where family is
- Don’t perceive the risk
- Beautiful views
Why some places are more vulnerable than others
- Low development level
- Lack of education
- Proximity to hazards
- Hazards are frequent
- Low level of preparedness
- Poor building design
- Poor governance
Short-term impact
Something that happens in the days and weeks after an event
Long-term impact
Something that continues to impact for months and years after an event
What category of the Saffir-Simpson scale was Typhoon Haiyan?
5
Short term impacts of Typhoon Haiyan
- 6300+ people killed
- 600,000 people displaced
- 30,000 fishing boats destroyed
- 14 million people affected by heavy rain
- power supplies disrupted
- flooding caused landslides
Long term impacts of Typhoon Haiyan
- Hospitals damaged, shops and schools destroyed
- 90% Tacloban city destroyed
- Shortages of water
- jobs lost
- 40,000 homes destroyed
Economic impacts of Typhoon Haiyan
- 30,000 fishing boats destroyed
- Crops destroyed
- Airport damaged
Social impacts of Typhoon Haiyan
- 14 million people affected by heavy rain
- 6300+ people killed
- 600,000 people displaced
Environmental impacts of Typhoon Haiyan
- Heavy rain
- Flooding caused landslides
- Blocked roads
- Crops destroyed
Short term impacts of Eyjafjallajokull
- 700 people evacuated due to glacier melt flood
- Mass grounding of flights
- Roads closed
- 500 local cattle farmers and families evacuated
Long term impacts of Eyjafjallajokull
- Plankton bloom due to ash in oceans disrupted food chains
- Kenya’s economy lost 2.8 billion pounds due to flight cancellations as goods not exported
- 2.8m tonnes of CO2 not emitted into the atmosphere
Economic impacts of Eyjafjallajokull
- Airlines lost a combined £130 million per day in revenues
- Europe’s biggest tourism businesses lost between £5 million and £6 million per day
Social impacts of Eyjafjallajokull
- 500 local cattle farmers and their families had to be evacuated from the area around the volcano
- Farmers near the volcano were warned not to let their livestock drink from contaminated water sources
Environmental impacts of Eyjafjallajokull
- Dissolved iron deposits triggered a plankton bloom
- The eruption on 14 April set off a major flood in Iceland
- The mass-grounding of European flights prevented the emission of 2.8m tonnes of carbon dioxide
When was the Eyjafjallajokull eruption?
March 20th 2010
Which plate boundaries are Eyjafjallajokull on?
North American and Eurasian
Which type of plate margin is Eyjafjallajokull on?
Constructive
What VEI was Eyjafjallajokull?
4
Short term impacts of the Nepal earthquake
- 8,600 dead and 19,000 injured
- people slept outside due to landslides and shaking destroying homes
- avalanches and landslides triggered
Long term impacts of the Nepal earthquake
- Harvests reduced or lost
- Entire villages lost to landslides
- Old buildings and UNESCO heritage sites lost
Economic impacts of the Nepal earthquake
- 35-50% of GDP lost
- Short term tourist revenue lost
Social impacts of the Nepal earthquake
- 8,600 dead and 19,000 injured
- people slept outside due to landslides and shaking destroying homes
Environmental impacts of the Nepal earthquake
- Landslides
- Avalanches
Which plate boundaries did the Nepal earthquake happen along?
Indian and Eurasian
Which type of plate margin is Nepal on?
Collision
What MMS was Nepal Earthquake?
7.8
Short term responses of the Italy earthquake
- Homeless were given tents or slept in sports halls
- 250 people rescued from collapsed buildings
- Power banks and generators given out to help communication
Long term responses of the Italy earthquake
- Safe Schools drill practices introduced
- 1 billion euros given for rebuilding work
- Casa Italia scheme for earthquake proof housing
How Italy was prepared for an earthquake
Emergency services and response teams trained and ready
When was the Italy Earthquake?
August 24th 2016
Which plate boundaries did the Italy earthquake happen along?
African and Eurasian
Which type of plate margin is Italy on?
Collision
What MMS was Italy Earthquake?
6.2
Ways buildings can be made earthquake proof
- Triangular shape (lightweight on top)
- Pendulum in roof (stabilize)
- Cross bracings (so building can twist)
Items in a emergency grab bag
- Flashlight
- Food
- Water
- Radio
- Shelter
Explain how GIS can be used for earthquake preparedness
- Mapping the roads
- building age mapping
- population density mapping
Explain how warning and evacuation are used to prepare for earthquakes
- People know what to do and where to go in the event of an earthquake
- People can prepare a grab bag in advance
Explain the role of remote sensing in earthquake preparedness
Can take images of the ground to monitor movements
Short term responses of the Nepal Earthquake
- Over 100 search and rescue responders were provided by The UK
- Temporary housing was provided, including a ‘Tent city’ in Kathmandu
- India and China provided over $1 billion of international aid
Long term responses of the Nepal Earthquake
- Stricter building codes were introduced
- Over 7000 schools were rebuilt
- A blockade at the Indian border was cleared in late 2015 (better transportation of goods)
How Nepal was prepared for earthquakes
- Tourists climbing Everest paid premium packages for emergency rescue and earthquake insurance
- Low development = little preparedness
Park model
Tells us how quickly a country can return to full quality of life (quality of life against time after disaster)
Natural Hazards
Extreme natural events that can cause loss of life, extreme damage to property and disrupt human activities
Destructive plate boundary
When two plates are moving towards each other and the edge of one plate margin is being destroyed as it plunges beneath the other plate (subduction).
Collision plate boundary
when two plates of equal density and strength move towards each other and meet head on
Conservative plate boundary
where two plates are sliding past each other, causing earthquakes
Hotspot
locations beneath the Earth’s crust where strong currents of magma (plumes) rise. Where the crust above a plume is weak, volcanic activity occurs
Earthquake
A sudden and brief period of intense shaking of the ground
Pyroclastic flow
a dense, destructive mass of very hot ash, lava fragments, and gases ejected explosively from a volcano and typically flowing at great speed
Hazard
An event which has the potential to cause harm to the environment, people or the economy
