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Volumn 303, Issue 5656, 2004, Pages 351-353

Inferences on Flow at the Base of Earth's Mantle Based on Seismic Anisotropy

Author keywords

[No Author keywords available]

Indexed keywords

ANISOTROPY; BOUNDARY LAYERS; MECHANICAL WAVES; TOMOGRAPHY; VELOCITY MEASUREMENT; WAVEFORM ANALYSIS;

EID: 0346373756     PISSN: 00368075     EISSN: None     Source Type: Journal    
DOI: 10.1126/science.1091524     Document Type: Article
Times cited : (158)

References (27)
  • 5
    • 0347584073 scopus 로고    scopus 로고
    • M. Gurnis, M. E. Wysession, E. Knittle, B. A. Buffett, Eds. (American Geophysical Union, Washington, DC)
    • T. Lay, Q. Williams, E. J. Garnero, L. Kellogg, M. Wysession, in The Core-Mantle Boundary Region, M. Gurnis, M. E. Wysession, E. Knittle, B. A. Buffett, Eds. (American Geophysical Union, Washington, DC, 1998), pp. 219-318.
    • (1998) The Core-Mantle Boundary Region , pp. 219-318
    • Lay, T.1    Williams, Q.2    Garnero, E.J.3    Kellogg, L.4    Wysession, M.5
  • 11
    • 0348213780 scopus 로고    scopus 로고
    • note
    • Our data set consists of three-component long-period seismograms (minimum period of 60 s for surface waves and 32 s for body waves) inverted in the time domain in the framework of nonlinear asymptotic coupling theory (9). In this normal-mode perturbation-based approach, we calculate two-dimensional great-circle sensitivity kernels that account for the distribution of sensitivity along and in the vicinity of the ray when using finite-frequency waveform data. Additionally, this approach allows us to use diffracted waves as well as simultaneously arriving phases, which is not possible when using ray theory- and travel time-based approaches (fig. S1 and SOM text).
  • 12
    • 0348213779 scopus 로고    scopus 로고
    • note
    • Siso and degree 8 for ξ.
  • 13
    • 0346953029 scopus 로고    scopus 로고
    • note
    • S and ξ. Tests with a random input model with a white wavelength spectrum indicate that we are capable of correctly resolving the long-wavelength ξ structure with some resolution at shorter wavelengths in the upper and lowermost mantle (fig. S3), but not in the bulk of the lower mantle. On this basis, we limited our inversion to degree 8 in ξ. Statistical tests also demonstrate improvement in fit significant at a 95% confidence level for the CMB-sensitive portion of the data set for the model with ξ structure in the lowermost 400 km of the mantle compared to an isotropic model (SOM text).
  • 20
    • 0348213777 scopus 로고    scopus 로고
    • note
    • As shown by resolution tests, only the long-wavelength features of our model are well constrained (13). Moreover, we have ignored azimuthal anisotropy, which may influence the details of our model, although radial anisotropy has been shown to adequately describe the data in many of the regional studies (5).
  • 22
    • 0002235083 scopus 로고    scopus 로고
    • M. Gurnis, M. E. Wysession, E. Knittle, B. A. Buffett, Eds. (American Geophysical Union, Washington, DC)
    • L. Stixrude, in The Core-Mantle Boundary Region, M. Gurnis, M. E. Wysession, E. Knittle, B. A. Buffett, Eds. (American Geophysical Union, Washington, DC, 1998), pp. 83-96.
    • (1998) The Core-Mantle Boundary Region , pp. 83-96
    • Stixrude, L.1
  • 27
    • 0348213778 scopus 로고    scopus 로고
    • note
    • This is contribution 03-10 of the Berkeley Seismological Laboratory. Supported by NSF grant EAR-9902777.


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.