Tectonic hazards Flashcards
What is a natural hazard?
It is when a natural event has the potential to endanger lives, the economy and property
What is a hazard risk?
A hazard risk is the chance or probability of being affected by a natural event
What is a natural disaster?
It is when a natural event does cause damage or does impact on people and their lives
What are atmospheric hazards?
It is created in the atmosphere by the movement of air and water
What is a geological hazard?
It is created by the movement of the Earth’s tectonic plate
What is a hydrological hazard?
It is created by rivers, sea and oceans
What are some factors increasing the risk from natural hazards?
Climate change
Urbanisation
Farming
Poverty
How does climate change increase the risk from natural hazard?
Warmer temperatures mean more evaporation and this means more flooding
1 degree Celsius equals 7% more moisture in the atmosphere. Warmer temps mean more energy in the atmosphere
How does urbanisation increase the risk from natural hazard?
55% of the world’s population live in urban areas. High populations in places mean more people are vulnerable to hazard risks
Impermeable surfaces increase risk from flooding
How does farming increase the risk from natural hazard?
Farmers live on flood-plains which are vulnerable to flooding
How does poverty increase the risk from natural hazard?
Poorer people live in high risk areas such as slums on steep slopes or bases of volcanoes and are therefore more vulnerable to hazards
What are the types of plate margins?
Destructive subduction plate boundary
Destructive collision plate boundary
Conservative plate boundary
How do faults form?
The Earth’s crust is constantly under pressure from forces within and around it. this pressure builds up over time and eventually causes the crust to break and this then becomes a fault
Why do people choose to live in areas at risk from tectonic hazards?
People may not be aware of the risks
People in poverty are more concerned about basic needs
They don’t happen that often
Benefits such as fertile soils and geothermal energy
Monitoring allows for advance warning
Better building designs
What is meant by monitoring?
Using scientific equipment to detect signs of events such as volcanic eruptions
What is meant by prediction?
Using historical evidence and monitoring to make predictions about when and where a tectonic hazard may occur
What is meant by protection?
Designing building/structures that will withstand tectonic hazards and their associated hazards eg educating people
What is meant by planning?
Identifying and avoiding places most at risk; devising emergency action in the event of hazard
How can you monitor for volcanic eruptions?
Use tiltmeters and GPS satellites to detect changing ground condition
Thermal heat sensors detect rising temps
Seismometers detect earthquakes which often precede an eruption
How can you predict volcanic eruptions?
Scientist’s can monitor tectonic activity and warn/evacuate people
How can you protect people and buildings from volcanic eruptions?
It is very difficult to do much to protect building and people
Designated volcano shelters
Possible to divert lava
Educating people
How can you plan for future volcanic eruptions?
Hazard mapping - map the typical direction of lava flows
Plan the emergency response and help communities to respond to and recover from disasters
How can you monitor for earthquakes?
Use seismometers to detect shaking
Use strain gauges to detect levels of stress in rocks
Use GPS satellites to detect movement in the ground
Looking out for strange animal behaviour
How can you predict earthquakes?
Earthquakes are difficult to predict as they generally occur without warning despite all the monitoring that takes place
There may be some signs just before an earthquake hits
How can you be protected from earthquakes?
Strict building regulations-cross bracing, damper systems, shock absorbers
Retrofitting buildings (modifying and strengthening buildings) eg shatter proof glass
Text message alerts
Educating people-regular earthquakes drills (Japan 1st September)
How can you plan for future earthquakes?
Hazard mapping-map the areas which are more vulnerable to shaking.
Plan the emergency response
How many people died/were injured in the Nepal Earthquake (2015)
9000 dead 20,000 injured
19 people died due to avalanches
How many people died/were injured in the Christchurch Earthquake (2011)
481 dead 2000 injured
How powerful was the Nepal Earthquake (2015) on the Richter scale?
7.9
How powerful was the Christchurch Earthquake (2011) on the Richter scale?
6.3
How many people were left homeless after the Nepal Earthquake?
3 million
How deep was the focus of the Nepal Earthquake compared to the Christchurch earthquake?
15km (Nepal)
5km (Christchurch)
What were some of the primary and secondary effects that followed after the Nepal earthquake?
Landslides
$5 billion damage
500,000 tents for homeless people.
Financial aid+search rescue teams from other countries
Stricter building codes.
Blockade at Indian border affected supplies of fuel and materials
What were some of the primary and secondary effects that followed after the Christchurch earthquake?
People affected mentally and needed support. Loss of income and jobs.
Rescue teams from all around the world
State of national emergency
Government provided temporary houses. NGOs helped
