SURFACE WAVES ( L-WAVES): UPSC Daily Important Topic | 6 February 2022

■ SURFACE WAVES ( L-WAVES)

Topic — Interior of Earth

✓ The body waves interact with the surface rocks and generate new set of waves called surface waves (long or L-waves). These waves move only along the surface.

✓ Surface Waves are also called long period waves because of their long wavelength.

✓They are low-frequency transverse waves (shear waves).

✓They develop in the immediate neighbourhood of the epicentre and affect only the surface of the earth and die out at smaller depth.

✓They lose energy more slowly with distance than the body waves because they travel only across the surface unlike the body waves which travel in all directions.

✓ Particle motion of surface waves (amplitude) is larger than that of body waves, so surface waves are the most destructive among the earthquake waves.

✓  They are slowest among the

earthquake waves and are recorded last on the seismograph.