pure and applied geophysics

, Volume 132, Issue 1–2, pp 331–362 | Cite as

Q measurements for PhaseX overtones

  • Emile A. Okal
  • Bong-Gon Jo


Linear stacking procedures are used to retrieve the attenuation of 91 modes belonging to the 3rd, 4th and 5th Rayleigh overtones branches in the 80–160 s period range, and contributing to the so-called “PhaseX” wave group. Our data show in general slightly less attenuation than expected from available models. Data space inversion shows that, when combined with previously measured fundamental modeQ's, this new dataset improves resolution significantly in the 1000–2000 km depth range. Based on this remark, we carry out a number of parameter space inversions. Our results suggest a narrow (80–200 km) zone of high attenuation (Qμ=75–90), low attenuation in the intermediate mantle (670–1500 km); (Qμ≈350), and lower values in the deeper mantle (Qμ≈200).

Key words

Mantle attenuation spheroidal overtones 


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Copyright information

© Birkhäuser Verlag 1990

Authors and Affiliations

  • Emile A. Okal
    • 1
  • Bong-Gon Jo
    • 1
  1. 1.Department of Geological SciencesNorthwestern UniversityEvanstonUSA

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