ANALYSIS OF K-LINE WAVENUMBER SPECTRA FROM THREE WMO NOISE SAMPLES. ADVANCED ARRAY RESEARCH

Abstract : The noise pattern at WMO was studied in detail in order to design an array of vertical and horizontal seismometers which would enhance teleseisms at WMO. This report discusses the analysis of the one-dimensional wavenumber spectra obtained from noise samples NS1, NS2, and NS3 recorded on 25 April 1962, 1 June 1962, and 27 April 1962, respectively. The major achievement of the analysis is the identification of broadband 0.2- to 1.0-cps Rayleigh-wave energy coming from the Lakes Lawtonka and Elmer Thomas in the northeast and of high- velocity P-wave energy. In addition to the northeastern Rayleigh energy and the high-velocity energy appearing at all frequencies from 0.2 to 1.0 cps, there is some indication of isotropic (nondirectional) Rayleigh-wave energy