Contents
R.Bojilova– Influence of geomagnetic activity on the ionosphere critical frequencies
E. Oynakov, I. Aleksandrova, D. Solakov – Variations of the parameters of background seismic noise in the stage of preparation of strong earthquakes in the Vrancea regionstorms
N. Dimitrov, P. Danchev, I. Georgiev – Investigation of the impact of atmospheric refraction on precision leveling measurements
N. Miloshev, P. Trifonova– What the National Geo information Center is going to change?
P.Trifonova, M. Metodiev, I Buchvarov– Digital data records in PAG Geomagnetic Observatory available for a 60 years period
M. Metodiev, P. Trifonova– Annual report of the observed geomagnetic activity in Panagyurishte Observatory for 2014
Anton Ivanov, Ivan Georgiev, Nikolay Dimitrov– Analysis of monthly sea level data from Varna tide gauge station
L. Christoskov, L. Dimitrova, D. Solakov, S. Simeonova – Forty years National Operative Telemetric System for seismological information
V. Buchakchiev, E. Oynakov, D. Dragomirov, Y. Milkov – Seismicity on the territory of Bulgaria and the adjacent lands recorded by NOTSSI in 2017
D. Dragomirov, E. Oynakov, V. Buchakchiev, Y. Milkov – Seismicity on the territory of Bulgaria and the adjacent lands recorded by NOTSSI in 2018
