Answer:
S Waves (Secondary waves)
Step-by-step explanation:
Due to exccess of the energy inside the earth when the tectonic plates begin to slide or fracture then the energy is released in the form of seismic waves, this causes the earth-quake.
Two types of seismic waves are generally responsible for the earth quakes:
Body waves are of two types:
- Primary waves (P-waves)
These are the fastest of all the waves involved in the earth-quake which travel at a speed of 1.6 km to 8 km per second.
They can pass trough solids, liquids and gases. They arrive at the surface as an instant thud.
2. Secondary waves (S-waves)
They can only pass through the solids and they move slower than the P-waves.
As S-waves move, they displace rock particles outward, pushing them perpendicular to the path of the waves resulting in the first period of rolling associated with earthquakes.