Seismic waves are elastic waves.

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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.
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Two types of Surface Waves
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Wavefronts and rays
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Period, amplitude and frequency
Equations for Vp and Vs
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Vp 1.7 Vs
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Since Vp gt Vs gt Vsw P waves generally arrive at
a station first.
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Mag 6.9 Earthquake in Kamchatka Recorded in Mount
Soledad
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What happen when the ray/wave hits an interface?
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Snells Law
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What happens to waves in the Earth?
Density increases due to pressure but so do the
bulk and shear moduli. Therefore rays bend!
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P-wave SZ is between 104 and 140. S-wave SZ
between 104 and 256
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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 PcP P
wave that bounces off outer core and goes to
surface PcS P wave that bounces off outer core
and converts to S which Travels to the
surface ScS S wave that bounces off outer core
and goes to surface etc
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Show movies. Homog.1.aviPrem-path.aviRaypath.av
i
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