Tectonic features Flashcards
How are fold mountains formed?
They are formed by the collision of continental plates at destructive plate boundaries.
What is the feature where rocks fold upwards?
Anticline
What is the feature where rocks fold downwards?
Syncline
Give an example of fold mountains.
The Himalayas
How are ocean trenches formed?
Where the oceanic plate sinks below the continental plate at destructive plate margins.
Give an example of an ocean trench.
The 11km-deep Pacific trench
How are mid-ocean ridges formed?
They are caused by two oceanic plates moving apart at a constructive boundary.
What can mid-ocean ridges lead to?
Mountainous or volcanic islands.
Give an example of mid-ocean ridges.
Iceland
Describe how earthquakes occur.
Plates move towards each other
Friction builds up
Pressure is released as the plate jolts forward
Earthquake occurs
Define ‘epicentre’.
The point underground where a quake begins. Energy is released from here when pressure builds up as plates push past each other.
Define ‘seismic waves’.
The line along which two plates meet and rub against each other. This line runs down from the surface, through the focus.
Define a ‘fault’.
The location on the surface directly above the focus. The quake is likely to be biggest and most damaging here.
Define a ‘focus’.
Shock waves of energy which travel through the crust to the surface when an earthquake starts. These are measured by a seismometer.
