Structrue Of The Earth Flashcards
(43 cards)
What does it mean by the earths surface is dynamic
It is constantly moving
What is evidence that the plates are moving?
Mountain ranges, ocean ridges and trenches, volcanoes, volcanic islands, earthquakes and tsunamis are clues and evidence that this is happening
What are the layers that make up the earth ?
What are the two types of plates?
Oceanic and continental
What move the plates ?
Convection currents.
Continental drift is the science of studying the movements in the earths crust
How and why are the plates moved?
Energy trapped during the ‘big bang’ and nuclear explosions in the core (6000km) down create vast amounts of heat. As this heat tries to escape it ‘boils’ semi molten rocks in the mantle and slowly moves the crust above it.
Constructive
Plates move apart e.g Mid Atlantic Ocean ridge (Iceland)
Destructive
Plates move together e.g Peru -chile trench subductive zone
Collision
2 continental plates ‘crash’ into each other e.g Himalaya mountains
Conservative
Plates side alongside each other e.g San Andreas fault, California
Active
A volcano that could erupt at any point
Dormant
A volcano that is ‘sleeping’ and has not erupt in years
Extinct
A volcano that unlikely/ never going to erupt again
What are the 2 shapes of volcanoes, their characteristics and examples?
Cone and shield Cone - sticky lava, violent eruption E.g destructive , mt merapi Indonesia Shield- runny lava , gentle eruption E.g hawian island (hot spot)
Ash
The smoke cloud travels for miles it can produce very fertile soil
Acid rain
Sulphur emissions causes acid rain, can poison or kill plant and animal life
Pyroclastic flow
Floods of gas, lava and rock rush down volcano after eruption. Hot gases and high speed, lethal to anything in path
Lahar
Mudflow dangerous due to energy and speed. Solidifies when stopped
Gas
Gas produced when eruption happens, co2, sulphur dioxide. Smell like rotten egg
Lava flow
Non explosive eruption, runny lava slowly burns the landscape
Where do most volcanoes occur
At constructive and destructive boundaries
Constructive volcanoes
These occur where plates move apart. Magma rises form mantle and reaches the surface. It solidifies and forms new crust. This process leads to a volcano. These boundaries are common in the middle of the ocean
Destructive volcanoes
These occur where the plates are moving towards each other. One plate is forced beneath and melts to form magma, which can lead to a volcanic eruption. This type of boundary is often found along coastal areas where oceanic and continental plates meet.
Who invented the Richter scale and what is it ?
Charles richter
It measures the magnitude of earthquakes
