THE ROLE OF THE NEWL Y CERllFIED SEISMOLOGICAL STATION VRAC IN THE FRAMEWORK OF THE INTERNA TIONAL MONITORlNG SYSTEM OF THE CTBTO

The problem of the nuclear weapons development and of the nuclear test connected with this development belongs to the most serious present political problem. The political effort to reduce the danger following from the nuclear weapons resulted in a Comprehensive Nuclear- Test-Ban Treaty (CTBT). The lntemational Monitoring System (!MS), built for verification of the keeping up the Treaty, consists offour networks including the seismic network!MS. Seismic network!MS consists of 50 primary stations and of 120 auxi1iary stations. The principa1 role of the primary stations is to detect the events. The auxiliary stations are necessary for the good location of these detected events. The VRAC station is the auxiliary station of the!MS CTBTO. lt provides indispensable data for location ofregional events in centra1 and southem Europe, which are detected mainly by the primary station GERESS. The data of station VRAC are also very important for good location of events from the southem Asia, from the westem margin of the Pacific plate, from the region ofthe Mid-Atlantic ridge etc. These data are important for complex processing and for reliab1e discrimination of records of nuclear explosions which could be carried aut in Asia. High-quality records could be provided also in the case of nuclear tests in the French Pacific polygon in the Tuamotu is1ands region. Úvod Problém vývoje jaderných zbraní a s ním spojených pokusných jaderných explozí patøí k nejvážnìjším politickým otázkám souèasnosti a dotýká se lidstva jako celku. Proto existuje dlouhodobá snaha o zastavení èi alespoò omezení jaderných experimentù. Tyto snahy vyvrcholily pøedložením "Smlouvy o úplném zákazu jaderných zkoušek " (Comprehensive Nuclear- Test-Ba