Accession Number : ADA262801


Title :   Studies of Regional Phase Propagation in Eurasia


Descriptive Note : Final rept. 16 Aug 1990-15 Dec 1992


Corporate Author : TELEDYNE GEOTECH ALEXANDRIA VA ALEXANDRIA LABS


Personal Author(s) : Jih, Rong-Song ; Lynnes, Christopher S


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a262801.pdf


Report Date : 31 Dec 1992


Pagination or Media Count : 61


Abstract : We investigated various issues related to the propagation of seismic waves in Eurasia during the period 16 Aug 1990 - 15 Dec 1992. This final report covers the research accomplished under the 2 tasks that have not been reported previously in the first annual report PL-TR-92-2042. Section I describes briefly how we derived a spherically symmetric velocity structure for the Garm region in Central Asia with travel-time residuals of regional phases recorded at the IRIS station GAR and and the CDSN station WMQ. In Section II, we conducted a tomographic inversion to determine the regional L sub g Q structure in the Iranian Plateau. Although the whole of Iran can be regarded as a region of very low Q, applying a simple averaged attenuation coefficient (Q) for the whole plateau would be inappropriate for the L sub g magnitude determination. The regional variation of the anelastic attenuation parameter is significant enough that it must be taken into account in calibrating each monitoring station for a reliable magnitude scale in monitoring possible clandestine tests from a vast area. Section III of this report gives a perspective overview of the whole project.


Descriptors :   *SEISMIC WAVES , TEST AND EVALUATION , VELOCITY , STATIONS , PROPAGATION , MONITORING , PARAMETERS , STRUCTURES , ATTENUATION , IRIS , TRAVEL TIME , ASIA , EURASIA , IRAN , DETERMINATION , DISCRIMINATION , TOMOGRAPHY , INVERSION , PLATEAUS , REGIONS , PHASE , VARIATIONS , RESIDUALS , SCALE , COEFFICIENTS , YIELD


Subject Categories : Seismology


Distribution Statement : APPROVED FOR PUBLIC RELEASE