Nuclear Treaties Branch

During the last two years, new regional travel-time tables for different provinces of Northern Eurasia were developed in the framework of the Seismoacoustic Research for CTBT Monitoring project. This project is being performed by SAIC and its subcontractors: the Western Services Corporation, the Geophysical Survey of the Russian Academy of Sciences (RAS) and Complex Seismological Expedition (CSE) of the Joint Institute of Physics of the Earth of the RAS. One of the main objectives of the project is to calibrate travel times for regional seismic waves travelling to the seismic stations of the Russian Academy of Sciences included in the Comprehensive Nuclear-Test-Ban Treaty International Monitoring System (IMS). The development of regional travel-time tables is based on the published data of origin times and locations of nuclear explosions as calibration sources. The data are from peaceful nuclear explosions on the territory of the former Soviet Union as well as underground nuclear tests at the Semipalatinsk test site, Amchitka Island, and the French Test Site in the Sahara. Values of arrival times for major regional seismic phases (Pn/P, Pg, Sn/S and Lg) were measured, analyzed and collected from the stations of the Geophysical Survey and Complex Seismological Expedition. The territory of Northern Eurasia was subdivided into 11 provinces based on the results of the analysis of Pn travel times as well recently published papers on seismic and tectonic regionalization of Northern Eurasia. At the 22nd Seismic Research Symposium we present newly developed travel-time tables for the following provinces: Central-East-European territory, Cenozoic Folded Regions (Balkan and Carpathian mountains, Crimea-Caucasus-Kopet