Seismic waves are elastic waves Four types 2

Seismic waves are elastic waves. Four types: 2 Body Waves. So called because they travel through the Earth. These are P & S waves. P = primary S = secondary or shear 2 surface waves. So called because they travel primarily on surface. These are Love waves and Rayleigh waves.

Two types of Surface Waves

Wavefronts and rays

Period, amplitude and frequency Equations for Vp and Vs

Vp ~ 1. 7 Vs

Since Vp > Vsw P waves generally arrive at a station first.

Mag 6. 9 Earthquake in Kamchatka Recorded in Mount Soledad

What happen when the ray/wave hits an interface?

Snell’s Law:

What happens to waves in the Earth? Density increases due to pressure but so do the bulk and shear moduli. Therefore rays bend!

P-wave SZ is between 104° and 140°. S-wave SZ between 104 ° and 256°

Labeling Waves. P = direct P S = direct S p = P-wave that travels up first s = S-wave that travels up first PP = One bounce at surface of P wave SS = One bounce at surface of S wave c = reflection from core K = P wave through outer core I = P wave through inner core i = P wave refected from inner core J = S wave through inner core Combine: Pc. P = P wave that bounces off outer core and goes to surface Pc. S = P wave that bounces off outer core and converts to S which Travels to the surface Sc. S = S wave that bounces off outer core and goes to surface etc

Show movies. Homog. 1. avi Prem-path. avi Raypath. avi