Year 9 Flashcards
What are natural disasters?
A natural event that causes great damage or loss of life
Name the three main types of Natural Hazards
Hydro-meteorological hazards, geophysical hazards and chronic hazards
What are the 6 forms of hydro-meteorological hazards?
Tropical storms, thunderstorms, droughts, floods, wildfires and tornadoes
What the the 2 forms of chronic hazards?
El Nino and global warming
What are the 5 forms of geophysical hazards?
Volcano, earthquake, tsunamic, landslide and avalanche
When does a hazard become a disaster?
When a hazardous event interacts with human and physical systems that are vulnerable
What are the four layers of the earth?
Mantle, inner and outer core and the crust
Who was Alfred Wegener?
A German scientist who in 1915 developed a theory that the continent originally formed a giant supercontinent
What was the supercontinent called according to Wegener?
The Pangea
What are two pieces of evidence used to support Wegener’s theory?
The shape of the east coast of South America fits the west coast of Africa, like pieces in a jigsaw puzzle; Matching rock formations and mountain chains are found in South America and Africa
Which part of the earth is the largest?
The mantle: 2900km
Which part of the earth is the hottest?
The inner core - 5000-7000’C
Why do plates move?
Convection currents in the earth’s mantle
What are tectonic plates?
Huge slabs of rock in the earth’s crust and upper mantle
Why do earthquakes and volcanic eruptions happen?
Occur at the boundaries of plates convection currents move the crustal plates in different directions driven by heat from the core produced by decay of radioactive elements
How are earthquakes measured?
Using a seismometer graded according to the Richter Scale - between 1 and 10
What is meant by magnitude?
The power of an earthquake
What’s a fault line?
Where two plates meet
What’s an epicentre?
The area where the most violent shaking occurs
What’s a collision plate margin?
Occurs when plates are forced together at great pressure so rocks crumble and form mountains. As the pressure builds, the friction sends shock waves to the earth’s surface causing an earthquake
What are primary effects?
Refer to the immediate and direct effects of the hazard e.g. deaths or collapsing roads/buildings for earthquakes
What are secondary effects?
The knock on effects occurring in the aftermath of an earthquake such as a tsunami, fire and damage to the tourist area.
What was the Nepal Earthquake?
Approx. 80km NW of Kathmandu, on the 25th of April 2015, measuring 7.8 on the Richter scale
What were the primary effects of the Nepal earthquake?
Hundreds of thousand homeless, villages flattened, old buildings destroyed at UNESCO World Heritage sites, 8,632 dead and 19,009 were injured.
What were the secondary effects of the Nepal earthquake?
Harvest reduced or lost, loss of 35% GDP, ST loss of tourist revenue, landslides and avalanches
What are social impacts?
Impacts on people
What are economic impacts?
Impacts on money
What caused the New Zealand earthquake ?
The earthquake was created along a conservative plate margin where the pacific plate slid past the Australian plate. It was a strike slip event along the fault line, consisting of mostly horizontal movement.
Which plates collided that caused the Nepal earthquake?
The eurasian and Indian plates
When was the New Zealand Christchurch earthquake?
2011
What were the primary effects of the New Zealand earthquake?
> 10,000 buildings damaged, 185 died, 700 injured, water pipes, roads, bridges, power lines and cell phone towers were broken and 80% of the water and sewerage system was severely damaged.
What were the secondary effects of the New Zealand earthquake?
By April 2013 the cost was $40bn, psychological impacts, 3.5m tsunami following a glacier calving, no longer able to host the Rugby World Cup, loss of tourism revenue and significant liquefaction affected the eastern suburbs which produced 400,000 tonnes of slit
What were the secondary effects of the New Zealand earthquake?
By April 2013 the cost was $40bn, psychological impacts, 3.5m tsunami following a glacier calving, no longer able to host the Rugby World Cup, loss of tourism revenue and significant liquefaction affected the eastern suburbs which produced 400,000 tonnes of slit
What’s meant by immediate/ST responses?
The reaction of people as the disaster happens and in the immediate aftermath