C2 - The structure of the Earth Flashcards
Where on the Earth’s crust do most volcanoes and earthquakes happen?
On tectonic plate boundaries.
What is the lithosphere?
The outer layer of the Earth above the mantle.
What are seismic waves?
Seismic waves are produced by earthquakes.
Why do tectonic plates not sink into the earth’s mantle?
This is because they are less dense than the mantle.
What happens when an oceanic plate meets a continental plate?
It subducts and sinks below as it is more dense and crates an earthquake.
What is igneous rock?
Igneous rock is made from the cooling of lava.
If an igneous rock has larger crystals, has it taken more or less time to cool?
It has taken more time to cool.
What is the difference between magma and lava?
Magma is below the surface of the crust whereas lava is above.
Why do scientists study volcanoes?
Scientists study volcanoes so they can predict future eruptions and also find out more about the structure of the earth.
Who came up with the idea of a supercontinent?
Alfred Wegener in 1914.
Why is silica-rich magma more dangerous than iron-rich magma?
This is because silica-rich magma is thicker and therefore may erupt more explosively.
