Surface Waves

Question 1

what directions so Rayleigh and Love waves propagate in?

Answer 1

Rayleigh waves are circular (sort of), whereas love waves are perpindicular to the direction of travel.
rayleigh are polarized to a vertical plane, whereas love are polarized to a horizontal plane

Question 2

what are the main properties of surface waves?

Answer 2

slower velocity, larger amplitudes, polarization, dispersion

Question 3

what body waves cause rayleigh waves?

Answer 3

P and SV waves cause rayleigh waves when they interact with the surface. when SV waves get post critical, emerging p waves are evanescent (decay exponentially with depth)

Question 4

whats the relationship between depth, and vertical and horizontal components of rayleigh waves?

Answer 4

vertical decays with depth, horizontal decays, but actually inverts direction first! the ellipitical shape gets narrower, then wider when it switches direction. related to modes of the soil medium.

Question 5

what components of p and s waves cause love waves?

Answer 5

SH componnents

Question 6

what is required to form love waves?

Answer 6

heterogenous media since it depends on different layers near surface to develop. they need at least one low velocity layer over the bedrock

Question 7

what decays more, surface waves or body waves?

Answer 7

surface decay at a rate proportional to 1/r, while body wave decay at a rate proportinal to 1/r^2. this is why surface waves are much more prominent on records

Question 8

what is dispersion ?

Answer 8

when two or more waves of similar frequency and velocity are occuring and they have an envelope around them that travels with different velocity and amplitude