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Journal of Seismology

, Volume 14, Issue 3, pp 481–493 | Cite as

Small-scale heterogeneities below the Lanzhou CTBTO seismic array, from seismic wave field fluctuations

  • Xuzhang ShenEmail author
  • Joachim R. R. Ritter
Original article

Abstract

Seismic wave field fluctuations below Lanzhou Comprehensive Test Ban Treaty Organization seismic array are determined and interpreted to describe the scattering characteristics of the crust beneath the northeastern margin of Qinghai–Tibet plateau in China. The frequency-dependent intensities of the mean and fluctuation wave fields are analyzed for 21 deep (206–632 km depth) teleseismic events. The observed wave field fluctuations in the frequency range 0.5–2.5 Hz can be explained by the scattering of the teleseismic P wave front at random media-type structures. The stable and narrow range of the fluctuation parameters from these teleseismic events indicates evidence for scattered seismic phases which are generated inside the crust. The reasonable structural models contain heterogeneities with 1–3% velocity fluctuations and 2.4–8.2 km correlation lengths in the crust with 53 km thickness.

Keywords

Scattering Heterogeneity Lanzhou CTBTO seismic array 

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Copyright information

© Springer Science+Business Media B.V. 2009

Authors and Affiliations

  1. 1.Lanzhou Institute of SeismologyChina Earthquake AdministrationLanzhouChina
  2. 2.Lanzhou Base of Institute of Earthquake PredictionChina Earthquake AdministrationLanzhouChina
  3. 3.Geophysical InstituteUniversitaet Karlsruhe (TH)KarlsruheGermany

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