Question

Distinguish between Primary and Secondary Seismic Waves

Answer 1

	Primary Seismic Waves	Secondary Seismic Waves
1.	The waves that reach the earths surface first once energy is emitted from the earths surface are called primary seismic waves.	The waves that reach the earths surface after the primary waves once energy is emitted from the earths surface are called secondary seismic waves.
2.	These waves can travel through all the three mediums of liquid, sold and gaseous states.	These waves can travel through only solid state medium and get absorbed in any liquid state mediums.
3.	They have high velocity and move in a radial direction from the focus of the earthquake.	They have lower velocity than Primary waves and scatter in all directions from the earthquake focus point.
4.	These waves are often called forward- backward waves as particles through which these waves pass tend to move to and fro in the direction of the waves.	These waves causes the particles it passes through to move up and down.
5.	Initial waves are felt but are not damaging to a great extent.	These waves are more damaging causing the maximum destruction during an earhquake.