Accession Number : AD0753110

Title :   Upper Mantle Q and Transmission Studies Using LASA and WWSS Data.

Descriptive Note : Final rept.,

Corporate Author : WISCONSIN UNIV MADISON GEOPHYSICAL AND POLAR RESEARCH CENTER

Personal Author(s) : Gettrust,Joseph F. ; Meyer,Robert P.

Report Date : 10 OCT 1972

Pagination or Media Count : 80

Abstract : Studies related to the crust and upper-mantle structure beneath the Montana LASA support the idea that the source of seismic time delays at the array includes the upper mantle. A study of the crustal transfer-ratio at LASA shows the complexity of ratio spectra for models concerned principally with the crust are not complex enough to fit actual data from the array. Thus, structure in the upper-mantle is suggested. A study of the earth's isostatic response to a concentrated load, which makes no a priori assumptions concerning the mechanism of compensation, suggests compensation is more complicated than the Heiskanen, Pratt, or Airy mechanisms would suggest and extends well into the upper mantle. A long-range seismic refraction study along the axis of the Rocky Mountains supports a double M-discontinuity. (Author)

Descriptors :   (*SEISMIC WAVES, MONTANA), (*STRUCTURAL GEOLOGY, UNITED STATES), SEISMOMETERS, NETWORKS, LITHOSPHERE, POWER SPECTRA, MOTION, REFRACTION, MOUNTAINS, MOHOROVICIC DISCONTINUITY, SEISMOLOGICAL STATIONS

Subject Categories : Geology, Geochemistry and Mineralogy
      Seismology

Distribution Statement : APPROVED FOR PUBLIC RELEASE