The Challenge of Natural Hazards: Paper 1 Section A Flashcards
Natural Hazard Definition
A Natural Hazard is a natural process which could cause death, injury or disruption to humans, or destroy property and possessions
Natural Disaster Definition
A natural hazard that has actually happened
Two Types of Natural Hazard
Geological Hazard
Meteorological Hazard
Geological Hazards
Caused by land and tectonic processes
Volcanoes
Earthquakes
Meteorological Hazards
Caused by weather and climate
Tropical Storms
Heatwaves
Cold Spells
Hazard Risk Definition
The probability of people being affected by a hazard in a particular
Factors that affect Hazard Risk
Vulnerability
Capacity To Cope
Nature of Natural Hazards
Capacity To Cope Hazard Risk
The better a population can cope with an extreme event, the lower the risk of them being severly affected
Vulnerability Hazard Risk
The more people that are in an area exposed to natural hazards, the greater the probability they will be affected by a natural hazard
Nature of Natural Hazards Hazard Risk
1) Type- the risk from some hazards is greater than others
2) Frequency- natural hazards that occur more often may carry a higher risk
3) Magnitude- more severe natural hazards tend to have the greatest effects
Primary Effects
- Buildings and roads destroyed
- People are injured or killed
- Crops and water supplies can be damaged or contaminated
- Electricity cables, gas pipes andcommunication networks can be damaged, cutting off supplies
Secondary Effects
- Initial hazard can trigger other hazards
- Aid and emergency vehicles can’t get through causing more deaths
- Shortage of clean water and lack of sanitation makes it easier for disease to spread
- Food shortages
- Country’s economy weakened
Long-Term Responses
- 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
- Improve building regulations
- Boost economic recovery
- Build Back Better
Immediate Responses
- Evacuate people
- Treat injured and rescue anyone cut off
- Recover dead bodies to prevent disease spreading
- Provide temporary supplies of electricity and gas
- Provide food, drink and shelter
- Foreign governments or charities may send aid workers, supplies or financial donations
Two Types of Crust
Continental (Thicker+Less dense)
Oceanic (Thinner+More dense)
Why do Plates Move
Convection Currents in the Mantle
Destructive Margin
- Two plates moving towards each other
- Oceanic meeting continental the denser oceanic plate is subducted and destroyed creating gas-rich magma. Volcanoes and Ocean Trenches occur here.
- Continental meeting continental ground folds upwards creating fold mountains
Constructive Margin
-Two plates moving away from each other
- Magma rises from the mantle to fill the gap and cools creating new crust
Conservative Margin
- Two plates moving sideways past each other or in same direction
- At different speeds
- Crust isn’t created or destroyed
- Build of friction then snap past causing earthquakes
Volcanoes Plate Margins
Destructive and Constructive
Earthquakes Plate Margins
Destructive, Constructive and Conservative
Moment Magnitude Scale
Measures the amount of energy released by an earthquake
Chile Earthquake Stats of Chile
- 27th Feb 2010
- 3:34 am
- 8.8 magnitude
- Destructive plate margin
- GDP per capita:
Chile Earthquake Primary Effects
- Around 500 people died, and 12,000 people were injured. Over 800,000 people were affected
- Two hundred twenty thousand homes were destroyed, along with 4500 schools, 56 hospitals and 53 ports
- The cost of the earthquake is estimated to be US$30 billion
- The earthquake disrupted power, water supplies and communications across Chile
Chile Earthquake Secondary Effects
- Tsunami waves devastated several coastal towns
- The tsunami struck several Pacific countries
- A fire at a Santiago chemical plant led to the local area being evacuated
- Landslides destroyed up to 1500 km of roads, cutting off remote communities for days
Chile Earthquake Immediate Response
- Emergency services responded quickly
- International support provided field hospitals, satellite phones and floating bridges
- Within 24 hours, the north-south highway was temporarily repaired, allowing aid to be transported from Santiago to areas affected by the earthquake
- Within ten days, 90% of homes had had power and water restored
- US$60 million was raised after a national appeal, which funded 30,000 small emergency shelters
Chile Earthquake Long-Term Responses
- Chile’s government launched a housing reconstruction plan just one month after the earthquake to help nearly affected 200,000 families
- Chile’s strong economy reduced the need for foreign aid to fund rebuilding
- The recovery took over four years
- Build Back Better
Nepal Earthquake Stats of Nepal
- Gorkha, Nepal
- 25th April 2015
- 11:26 am
- GDP per capita: US $690
- Destructive plate margin
- 7.8 magnitude
Nepal Earthquake Primary Effects
- Around 9000 died and more than 22000 were injured
- Estimated 800,000 buildings damaged or destroyed
- 4 million left homeless
- Cost was US $5 billion
- Roads and bridges destroyed
- Water tanks and pipes destroyed, leaving 2 million without access to clean water and sanitation
Nepal Earthquake Secondary Effects
- Earthquake triggered avalanches on Mount Everest killing 18 people
- Many mountain roads blocked by landslides preventing emergency aid reaching remote areas
- Lack of clean water caused outbreaks of typhus which killed atleats 13 people
Nepal Earthquake Immediate Responses
- India and China sent teams to help residents rescue people trapped by debris but a lack of tool and machinery slowed down rescue efforts
-People tried to recover the dead and treat the injured but damaged roads made it hard for emergency workers and aid to get through - Charities such as Oxfam provided medicine, food and temporary water supplies
- The Red Cross set up emergency shelters for 130,000 families who had lost homes
Nepal Earthquake Long-Term Responses
- World Bank Group financed $500 mil worth of projects
- ## Road from Nepal to Tibet reopened 2 years after but many other routes remain damaged
