Open AccessFrequency dependence of Q in the mantle underlying the shield areas of Eurasia, Part I: analyses of short and intermediate period data
Author(s) -
Der Zoltan A.,
Lees Alison C.,
Cormier Ver F.,
Anderson Lisa M.
Publication year - 1986
Publication title -
geophysical journal of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0016-8009
DOI - 10.1111/j.1365-246x.1986.tb01983.x
Subject(s) - mantle (geology) , shield , geology , amplitude , tectonics , period (music) , seismology , baltic shield , geophysics , spectral line , physics , petrology , optics , astronomy , acoustics
Summary. The results of short and intermediate period data analyses for the determination of a frequency dependent Q model of the mantle under the shield areas of Eurasia are presented. The spectra of short period P ‐waves from nuclear explosions in the 1‐8 Hz frequency range give t p *∼ 0.15‐0.2 s. Using recordings of Soviet nuclear explosions at NORSAR, P ‐wave profiles were assembled to study Q in the upper mantle under the Russian‐Fenno‐scandian shield. Analyses of the relative amplitudes and frequency contents of the various upper mantle arrivals support the existence of an upper mantle low Q layer under this region, but the Q p in this layer is high, around 700, compared to well studied tectonic regions of the western United States. A variety of measurements were used in the 0.3‐1 Hz intermediate frequency band including S ‐wave periods, P and S rise times, ScS‐ScP periods, and S‐SS periods, giving t S *∼ 2 to 3 s, or t P *∼ 0.5 to 0.75 s.