Plate Tectonics Flashcards
What is a natural event?
A natural event is something that happens naturally but doesn’t effect people
What is a natural hazard?
A natural hazard is something that happens but does effect people, eg, an earthquake
What is the inner core?
The inner core is the centre of the earth it is made of solid metal, is 750 miles wide and is 2760’c
What is the outer core?
The outer core is made of liquid rock (nickel and iron) and is 1400 miles wide
What is the mantle?
The mantle is below the crust it is made of hard and soft rock
What is the crust?
The crust is 20-60 miles wide ( continental), 3-6 miles wide ( oceanic )
What are tectonic plates?
Massive slabs of rock that make the earths crust
What are plate boundaries?
The place where two plates meet
What are convection currents?
The currents in the mantle that make the plates move
What happens at a constructive plate margin?
The plates are moving apart, this cause magma to rise and form new oceanic crust. This results in u detested volcanoes and countries such and Iceland
What happens at a conservative plate margin?
The two plates are sliding past each other. They get stuck on each other and cause tension, when the tension is released and earthquake occurs. An example is the San Andreas fault line.
What happens at a collision plate margin?
The two plates are moving towards each other. Both plates are continental, the crust is crumpled upwards to form fold mountains, an example is the Himalayas where the Eurasian plate has collided with the Indian plate
What happens at a destructive plate margin?
The two plates are moving towards each other, however the oceanic plate is being pushed under the continental plate as it is denser l, this forms a trench. Volcanoes are formed here
What is the epicentre?
The centre of the earthquake above land
What is the focus?
The centre of the earthquake below land, aka the start of the quake
What are seismic waves?
The waves of an earthquake
What are primary impacts?
Direct or immediate impacts- houses falling down
What are secondary impacts?
Something that happens because of the primary impacts- homelessness
When was the Nepal earthquake?
April 25th 2015
How strong was the Nepal earthquake
It had a magnitude of 7.9
Where was the epicentre of the Nepal earthquake?
The epicentre was about 80km to the north west of Kathmandu
What plates were involved in the Nepal earthquake?
The indo-Australian plate and the Eurasian plate
How many people were left homeless in Kathmandu?
300,000
Where did the Chile earthquake happen?
200 miles away from Santiago, the focus was 22 miles deep
What plates were involved in the Chile earthquake?
The Nazca plate and the South American plate
How strong was the Chile earthquake?
It’s magnitude was 8.8
When was the Chile earthquake?
27th Feb 2010
How many people were killed in the Chile earthquake
500
What is a shield volcano?
A shield volcano is less dangerous than a composite volcano, it is very wide and the lava is very think and slow
What is a composite volcano?
A composite volcano is very dangerous, it is cone shaped and the lava is very fast moving and has strong eruptions
What is a hotspot volcano?
A hotspot volcano is when the lava can get through the crust because it is thin causing a volcano an example is Hawaii
What is a benefit of living next to a volcano?
The soil is fertile because of the ash
What should you put in an earthquake preparation kit?
- fire extinguisher
- first aid kit
- water purifying tablets
- blankets
- torch
- radio
- tinned food
- stove
- tent
- knife
- dried food
What can be used to made earthquake proof buildings?
Counter weights- placed on top of the buildings to help counter the effects of sway when the ground shakes
What can be used to protect people from tsunamis?
GPS Boys
Early warning sirens
Evacuation routes
Evacuation towers
How can you tell if a volcano is going to erupt?
You can monitor the gases coming from the volcano
Watch for bulges on the sides
Monitor seismic activity
Monitor surface temperature
