L12_WavesAndRays-page7 - Therefore high frequencies decay...

Info icon This preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
Applied Geophysics – Waves and rays - I Attenuation The amplitude of an arrival decreases with distance from the source 1. Geometric spreading Energy spread over a sphere: 4 µ r 2 Amplitude 1/r 2. Intrinsic attenuation Rocks are not perfectly elastic. Some energy is lost as heat due to frictional dissipation. Amplitude e - α r where α is the absorption coefficient (dependent on wavelength) Total attenuation A = (A 0 e - α r )/r Higher frequencies attenuate over shorter distances due to their shorter wavelengths.
Image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Therefore, high frequencies decay first leaving a low frequency signal remaining. Applied Geophysics – Waves and rays - I Reflection and transmission Seismic rays obey Snell’s Law (just like in optics) The angle of incidence equals the angle of reflection, and the angle of transmission is related to the angle of incidence through the velocity ratio. 2 1 1 sin sin sin P P P P P P V r V R V i = =...
View Full Document

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern