Search Results - (Author, Cooperation:G. Laske)

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  1. 1
    Staff View
    Publication Date:
    2013-11-08
    Publisher:
    Nature Publishing Group (NPG)
    Print ISSN:
    0028-0836
    Electronic ISSN:
    1476-4687
    Topics:
    Biology
    Chemistry and Pharmacology
    Medicine
    Natural Sciences in General
    Physics
    Published by:
    Latest Papers from Table of Contents or Articles in Press
  2. 2
    Laske, G.

    Oxford, UK : Blackwell Publishing Ltd
    Published 1995
    Staff View
    ISSN:
    1365-246X
    Source:
    Blackwell Publishing Journal Backfiles 1879-2005
    Topics:
    Geosciences
    Notes:
    In the current generation of global dispersion maps of surface waves, the long-wavelength structure seems to be very well determined. There is general agreement in the patterns of global phase velocity anomalies up to harmonic degree 16. However, the shorter-wavelength structure varies significantly between published maps, and it appears that this part of the models depends strongly on the inversion technique and on the data set of surface-wave dispersion (usually phase measurements). Polarization data depend on the lateral gradient of phase velocity and hence are more sensitive to shorter-wavelength structure than phase data; thus, including these data should enhance resolution. In this paper, I demonstrate that polarization data of long-period surface waves (80 s), as a function of frequency, can be reliably measured using a multitaper technique. the resulting off-great-circle arrival angles of the surface-wave packets are relatively easy to interpret within a ray-theoretical framework. Our data base of three-component recordings is now large enough to provide useful constraints on global dispersion maps, particularly on the shorter-wavelength parts. Apart from the phase velocity model itself, a possible misorientation of the horizontal components at each station is included in a non-linear inversion as an additional independent model parameter. This gives a significant improvement in the fit to the data. Misorientations of more than 3° are probable for at least four of the 37 stations investigated.
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  3. 3
    Laske, G. ; Masters, G. ; Zurn, W.

    Amsterdam : Elsevier
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    ISSN:
    0031-9201
    Source:
    Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics:
    Geosciences
    Physics
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses