Earthquakes and volcanoes Flashcards
At what type of plate boundary do plates move together?
Destructive
In which direction do plates move at a destructive boundary?
Together
In which direction do plates move at a constructive boundary?
Apart
What is the name of a plate boundary where the plates slide past each other side by side?
Conservative
What is the name given to the tectonically active area around the Pacific Ocean?
Pacific Ring of Fire
Where do volcanoes and earthquakes tend to occur?
On plate boundaries
Why do earthquakes occur at a destructive plate boundary?
Because friction builds up as the plates slide past each other.
What two types of crust (usually) meet at a destructive plate boundary?
Oceanic and Continental crust
Why do tectonic plates move?
Because of convection currents in the mantle.
What scale is used to measure the magnitude, or strength of an earthquake?
The Richter Scale
Which instrument is used to measure seismic waves?
A seismometer
What is the name given to the exact point where an earthquake occurs?
The Focus - this will be underground
What is the name given to the point on the surface directly above where an earthquake occurred?
The Epicentre
What is a tsunami?
A giant wave triggered by an earthquake under a seabed.
What do the terms ‘active’, ‘dormant’ and ‘extinct’ mean when talking about a volcano?
Active - Is regularly erupting. Dormant - Sleeping - The volcano has been inactive for a long time, but it will erupt again one day. Extinct - The volcano will never erupt again.