Accession Number:

ADA237622

Title:

Propagation of Regional Seismic Phases in Western Europe

Descriptive Note:

Final rept. 15 Jul 87-14 Jul 90,

Corporate Author:

RADIOMANA PARIS (FRANCE)

Report Date:

1991-03-08

Pagination or Media Count:

77.0

Abstract:

This report describes the main results achieved during the reporting period for the following researches. 1 Propagation of regional phases in Western Europe. 2 Determination of QLg and Q coda in the 1 to 15 Hz frequency band. Geographical variations of Q are strongly correlated to the tectonic features and to other geophysical anomalies. This result correspond to the attenuation of Lg phases propagating through the positive Bouguer anomaly in the Western Alps. Those variations in Q were not only observed but also modeled. 3 Far field effects due to the structure near the joint sources numerical computations show variation of mb up to 0.25 at teleseismic distances induced by variations in the shape of the basement beneath a seismic event. 4 Source evaluation at teleseismic distance we observed limitations in the relative magnitude determination of Eastern Kazakh events in using the French seismic network. The source functions computed with this network are definitively different for events originating in the NE or in the SW of Shagan River.

Subject Categories:

  • Geology, Geochemistry and Mineralogy
  • Seismology
  • Seismic Detection and Detectors
  • Nuclear Weapons

Distribution Statement:

APPROVED FOR PUBLIC RELEASE