Earthquakes Flashcards
What causes earthquakes?
Earthquakes are vibrations of the earth’s crust caused by movement at plate boundaries and major fault lines.
Where can earthquakes occur?
Earthquakes can occur at all four major plate boundaries.
Where are the most severe earthquakes typically found?
The most severe earthquakes can usually occur at conservative and destructive plate boundaries.
What is an earthquake?
An earthquake is when the ground shakes, caused by sudden movement between plates.
What are seismic waves?
Earthquakes produce long shock waves called seismic waves.
How do seismic waves travel?
Seismic waves travel out from the centre of the crust just like a stone being thrown into a pond.
What is the focus of an earthquake?
The focus is the point where the earthquake starts.
What happens to seismic waves near the focus?
Near the focus, the waves are stronger which causes more damage.
What is the epicentre of an earthquake?
The epicentre is the point on earth’s surface directly above the focus.
How is the magnitude of an earthquake measured?
A Richter scale can be used to measure the magnitude of a tremor using an instrument called a seismograph.
What type of scale does a seismograph use?
A seismograph uses a logarithmic scale.
How does the logarithmic scale work for the Richter scale?
On a logarithmic scale, a size 6 on the Richter scale is 10 times larger than a size 5 and 100 times larger than a size 4.
What is the amount of energy released in an earthquake called?
The amount of energy released in an earthquake is called its magnitude.
How is the magnitude of an earthquake measured?
Magnitude of an earthquake is measured on the Richter scale.
