Plate Tectonics Flashcards
What is the crust?
The solid layer of rock on the surface of the earth, it varies thickness from 3-30 miles
What is the mantle?
The semi liquid layer of magma and molten rock that moves due to convection currents
What is the outer core?
The liquid portion of the core which has a similar composition to the inner core
What is the inner core?
The solid part at the centre of the earth it is made of iron and nickel name reaches temperatures of 5,500 degrees celsius
What are the seven main tectonic plates?
Eurasian Plate, North American Plate, South American Plate, Indo-Australian Plate, African Plate, Pacific Plate and Antartican Plate
What is the crust made up of?
Seven large sections and various smaller ones
What causes convection currents?
The heat from the inner core boils the mantle and moves the crust above them
How do convection currents move?
They rise and fall as they cool
Fill the blank: ‘Convection Currents move in ____________’
Cells
What is an example of a constructive plate boundary?
The Eurasian and North American plate boundary
What occurs at a constructive boundary?
Volcanoes
What is happening at a constructive boundary?
The plates are moving away from each other
What happens at a destructive plate boundary?
One plate subducts under another
Do volcanoes occur at destructive plate boundaries?
Yes
What is an example of a destructive plate boundary?
The Nazca plate and the South American plate
What happens at a collision plate boundary?
Two plates crash into each other
What occurs at a collision boundary?
Fold mountains and earthquakes
What happens at a conservative plate boundary?
Two plates pass by eachother
What is an example of fold mountains?
The Himalayas
What is an example of a collision plate boundary?
Where the Eurasian and indo-Australian plate meet
What occurs at a conservative plate boundary?
Earthquakes and volcanoes
What is a volcano?
An opening or culture in the earth’s surface that allows hot magma, ash and gases to escape from below the surface
What is the main vent?
The opening for the magma to go up through the volcano
What is a magma chamber?
The source of molten rock
What is the crater?
The circular basin shale on top of the volcano
What is the secondary/side vent?
A secondary vent formed in the side of the mountain
What is a volcanic bomb?
Airborne material from a volcanic esplosion
What is an active volcano?
A volcano that could erupt at any point
What is a dormant volcano?
A volcano that is sleeping
What is an extinct volcano?
An inactive volcqnoe
Why is volcanic ash dangerous?
It travels for miles, reducing visibility and settles as ashfall
Why is volcanic gas a danger?
It is made up of carbon dioxide and sulphur dioxide which is very bad for you
What does volcanic gas smell like?
Rotten eggs
What causes volcanic acid rain?
Sulfar
What is acid rain dangerous to?
Plant, animal and human life
What is Lahar?
Mudflow that comes from a volcano
Why is lahar dangerous?
It contains a lot of energy and goes very fast
What is pyroclastic flow?
Floods of gas, lava and rock that rush down the volcano after an eruption
Why is pyroclastic flow dangerous?
They have hot gases and are moving at a very high speed
What is lava flow?
Thick molten rock that travels long distances before solidifying
What does lava eventually lead to once weathered?
Fertile soil
What does geothermal energy do to energy costs?
It massively reduces them
What does a spectrometer do?
Measures the amount of sulphur dioxide gas emitted by a volcano
What does a seismometer do?
Measures the movement of magma
What does a tiltmeter/geodimeter do?
Measures changes in shape of the volcano
What happens to the water temperature in lakes and ponds before an eruption?
It increases
What is an earthquake?
A vibration of the earth’s crust caused by movement at plate boundaries and major fault line
Where do the most severe earthquakes occur?
At conservative and destructive boundaries
What is the focus point?
Where the seismic waves begin
What is the epicentre?
Directly above the focus on the earth’s surface. This is where the damage is greatest
What does the Richter scale measure?
The magnitude of the earthquake
How strong is a Richter scale 1 earthquake (ie. How much damage)
You wouldn’t even notice it
How many times stronger than 1 is a Richter scale 2 earthquake?
30x
How many times stronger than 2 is Richter Scale 3 earthquakes?
30x
What damage would a Richter scale 5 earthquake cause?
Breaks windows
How much damage does a Richter scale 6 earthquake cause?
Damages buildings
How much damage does a Richter scale 7 earthquake cause?
Major catastrophe
What is the highest earthquake ever recorded?
9.5
Why do earthquakes happen?
Plates slide and very quickly release tension
Where is a constructive plate boundary?
Between the North American and Eurasian plates
What is an example of a destructive plate boundary?
Between the Nazca and South American Plates
What is an example of a collision plate boundary?
Between the Eurasian and Indo-Australian plates
What is an example of a conservative boundary?
Between the Pacific Plate and the North American Plate
What factors can affect earthquake damage?
Size of the earthquake, physical landscape, time of day, building design and construction, emergency service response, GDP and education
What are some factors that can help earthquake-proof a building?
Rolling weights to counteract the shock waves, open assembly points, rubber shock absorbers, deep foundations and shutters that come down over windows
What are the 3ps to prevent earthquake damage?
Plan, protect, predict
