Waves Flashcards
What is the energy released by Earthquakes expended into?
Shock waves.
Where do shock waves begin?
Focus - waves become weaker the further away.
Epicentre directly above focus on surface of the Earth.
How do the waves travel from the focus?
They travel through rocks, from the centre of the Earthquake through Earth’s interior or along surface.
Name the 3 groups of waves?
Primary - P
Secondary - S
Surface - L
What are primary waves ?
They move the fastest meaning they arrive first by compressing rock in front of them and elongating it behind them ( to and fro).
Move through solids, liquids and air.
What are secondary waves?
They arrive second more slowly then primary waves.
Movement is up and down, side to side.
Only move through solids.
Cause more damage then primary waves.
What are surface waves?
They are the slowest waves but most destructive.
Movement is on the surface restricted to ground surface.
2 types - Love and Rayleigh waves.
What are LOVE waves?
They vibrate at right angles to the direction of transmission, no vertical displacement.
What are RAYLEIGH WAVES?
Both vertical and horizontal movement in vertical plane pointing in the direction of the transmitted wave.
What occurs at the focus?
The point of maximum displacement occurs at the focus which the shock waves originate deep in the crust.
What happens at the epicentre?
Point vertically above at the surface.
Shock waves erupt at the surface causing immense disturbance of the land - huge ripples spreading out.
What happens when the waves erupt onto the surface of the Earth?
The land can bulge and crack.
May trigger rock falls, landslides and avalanches.
