Recent achievement: Modernization of the National Operative System for Seismological Information Station Vitosha (VTS, since 1979) was included in the MEDNET project and was updated with STS-1 and Quanterra 380. The VTS-MEDNET station became fully operational since May 13, 1996. Then, in 2003, two stations: Plovdiv (PLD since 1977) and Jambol (JMB since 1982) were equipped with Q330 data loggers and Guralp CMG-40T broad-band sensors (link) with government funding. Since 2004, the real-time data transmission from stations Vitosha, Plovdiv and Jambol became available via leased digital telephone lines. Data from VTS, PLD and JMB stations are collected in real (near-real) time using the SeisComp/SeedLink software. The existing National Seismological Data Center (NSDC) in the Geophysical Institute, Sofia, was upgraded as a permanent center disseminating earthquake data in real time (near real time) to other centers within Europe and its surroundings. NSDC was equipped with COMPAQ computer and SUN workstation. A real-time data transfer to INGV, Roma and ORFEUS Data Center is implemented. Regional real-time data exchange between Bulgaria and Romania, Slovakia, Slovenia, Austria and Czech Republic is established. The upgrading is done in close consultation with ORFEUS and the MEREDIAN consortium member GFZ, Germany. As of September 2005 NOTSSI comprised 14 permanent seismic stations: 3 broadband digital seismic stations, 11 with analog telemetry via leased telephone lines, two local networks and NSDC in Sofia. In 2005, the Permanent Commission for Prevention of the Population from Natural Disasters and Catastrophes (now Ministry of State Policy for Disaster Management) supported the Geophysical Institute for overall modernization of the seismological network. After evaluation of competitive bids, REF TEK was awarded the contract to upgrade the existing national seismological network to a modern technology digital network. The equipment was delivered to the Geophysical Institute by the middle of November with the turn-key network installation being started at the end of November. In less than 10 days, all 11 stations located around the country were installed and transmitted data in real-time to the NSDC using the VPN and MAN networks of the Bulgarian Telecommunication Company. After the installation of REF TEK equipment, the upgraded NOTSSI network now consists of 14 stations equipped with 11 REF TEK High Resolution Broadband Seismic Recorders, model 130-01/3, 3 Quanterra recorders, models Q330 (two stations) and Q380 (one station). The network is equipped with a very broadband sensor (one station), broadband (8 stations), and short period seismometers (3 stations). Real-time data acquisition is performed using REFTEK’s full duplex error-correction protocol RTPD. The data from the Quanterra recorders are fed into RTPD in real-time via SeisComp/SeedLink protocol. Real-time and interactive data processing performed by the Seismic Network Data Processor (SNDP) software package running on two clustered SUN Fire V240 Servers. Network command/control and monitoring are performed by RTCC and RTPMonitor user interfaces which are running on two SUN Blade 1500 Workstations. Both RTCC and RTPMonitor serve up html pages that can be displayed in any standard web browser allowing the end-user to monitor the network status and control the acquisition parameters anytime and anywhere from any computer connected to the Internet. Thus during 2005 with financial support of the Permanent Commission for Prevention of the Population from Natural Disasters and Catastrophes, with the expertise gained by our staff from participation in the EU project MEREDIAN-2 and enthusiasm of the project team NOTSSI was switched from analogue, short period one component recording to 3-component, broad-band on-site digital recording, automatic processing and digital data analyses. The new system corresponds to the highest European standards in earthquake monitoring and data processing and fulfills the requirements of the National authorities and society (for details click here).