Year 9 Exams Flashcards
Convergent plate boundary
2 plates that meet one slides under the other this is called subduction
Divergent plate boundaries
2 plates that are moving away from each other
Conservative plate boundaries
Rising magma causes plates to slide closer or away from each other (no crust is destroyed or created)
How do tectonic plates move?
CONVECTION CURRENTS causes the crust (plates) to collide, slide or be pulled apart leading to earthquakes and volcanoes.
What is a tsunami?
Oceanic waves caused by under sea earthquakes and volcanic eruptions that can travel up to 900kmph
How are volcanoes formed?
They are formed where molten rock from the magma chamber erupts onto the surface through a vent. And the magma solidifies to form rock
Pangea
The earth before continental drift occured a big landmass
Continental drift
The continents drifting apart due to movement in the tectonic plates
Who first discovered contintal drift and what evidence did they show?
Alfred wegener, Africa looked like it fit lick a jigsaw to south america
Primary hazard
An impact that occurs immediately after an event
Secondary hazard
An impact that happens days or weeks after an event
Primary hazard of a volcano:
Pyroclastic flow, volcanic bombs, acid rain
Secondary hazards of a volcano
Mudflows, landlides, food and water shortages, disease, acid rain
Where is china?
Northen hemisphere, eastern asia, south of Russia, north east of India, north west of Pacific ocean, Bejing is the capital
Gdp
Total amount of money earned by a country
Gdp per capita
Total number of money earned by a country divided by the amount of people that live there
What was the urban population of china in 1975?
150 million
What is the urban population of china currently
750 million
What is happening to rural population currently
It is decreasing
What is happening to China
It is experiencing urbanisation
What is the ring of fire?
An arc of geological destruction surrounding the pacific ocean
What percentage of the worlds volcanoes occur along the ring of fire
75 percent
What percentage of the worlds earthquakes occur along the ring of fire
90 percent
Name 3 countries that border the ring of fire
Japan, chile, mexico
What is viscosity
The more silica there is the harder it is to be runny
What is silica
It changes a volcanoes eruptiom
Date of the boxing day tsunami?
26th december 2004- 8AM
Location of the boxing day tsunami
northen sumatra ,Indian ocean and indonesia
Number of deaths caused by the boxing day tsunami
230,000 deaths
Magnitude of the boxing day earthquake
9.3MW
Why did the boxing day tsunami occur
A large earthquake occured under the indian ocean
What type of plate boundary did the earthquake occur on
Convergent
What were the names of the plates involved
Indo australian sunducts beneath the eurasion plate
Name some economic impacts
14 billion dollars worth of damage, ports ruined, fishing industry devestated, loss from lak of tourism, many of the countries affected are emerging, forests were removed for tourism therefore there was less natural protection
Name some environmental impacts of the tsunami
Crops destroyed, farm land ruined by salt water, 8 million litres of oil escaped from oil plants, forests along the coast were destroyed, coral reefs and wetlands damaged.
Name some social impacts of the tsunami
1.7million people were made homeless, 5-6 million people needed emergency aid,threat of disease due to sewage and salt water and fresh water mixing, 1500 vilages destroyed in northen sumatra, foreign visitors dropped 80% in phuket (thailand) in 2005, 60& of sri lankas fishing fleet were destroyed.
