Long-term observations of geophysical fields form one of the pillars of activities of the Institute of Geophysics. We record earthquakes and other seismic events in the territory of the Czech Republic and abroad, we measure temperatures at the surface and in wells, gravity and electromagnetic fields. Observed data is used to study the structure of our planet and the processes in the Earth. Data is available on the portal of the infrastructure project CzechGeo/EPOS which is supported by the Ministry of Education of the Czech Republic.
Czech regional seismic network monitors earthquakes, rockbursts and explosions in mines in the Czech Republic, in central Europe and globally. It consists of twenty broadband stations situated in the territory of the Czech Republic. Data is transferred in real time to the data center at the Institute. Seismic service performs daily analysis of earthquakes, creates bulletins of readings of seismic stations and catalogues regional events. Digital data is provided to international data centers and serve e.g. to expedite the location process of prominent earthquakes in the world.
Local seismic network WEBNET monitors seismic activity in West Bohemia which is known for the occurance of earthquake swarms. Hot and cold mineral springs, and increased CO2 flux (Soos or Hartoušov moffetes) are other signs of the ceasing volcanic activity in the region. The dense network of seismic stations is operated by the Institute of Geophysics jointly with the Institute of Rock Structure and Mechanics.
Local seismic network REYKJANET is deployed in Reykjanes penninsula in the southeastern tip of Iceland Mainshock-aftershock sequences as well as earthquake swarms occur in this region close to the North Atlantic ridge. Stations in the REYKJANET network operate in off-line regime. Data is copied several times a year during the service visit of the stations and sent to the Institute of Geophysics in Prague for processing. The network of seismic stations is operated by the Institute of Geophysics jointly with the Institute of Rock Structure and Mechanics.
MOBNET is a pool of seismic stations installed temporarily in tectonically different regions in the frame of collaborative seismic experiments. The pool consists of 65 portable units. About half of the seismometers of the pool are short period Lennartz Le-3D sensors, the rest are tree-component broad-band seismometers – Streckeisen (STS-2) and Guralp (CMG-3T, CMG-3ESP, CMG-40T). GAIA data acquisition systems work mostly in offline regime. MOBNET stations have been deployed in international passive seismic projects RETREAT, LAPNET, PASSEQ, MOSAIC, BOHEMA and AlpArray.
Geothermal network GeoCLIMANET consists of three stations in the Czech Republic (Praha, Kocelovice, Svojšice), one station in Portugal (Evora-Caravelinha) and one station in Slovenia (Malence). All the stations monitor air and soil temperatures at different depth levels between the surface and a depth of 1 m. Except Svojšice, all stations measure also bedrock temperatures at depths between 40 m to 190 m. The observed data is used for the analysis of the air – ground surface temperature coupling and the heat transfer in different climatic, pedological and environmental conditions.
National geomagnetic observatory Budkov is situated in the southern Bohemia, in the district of Prachatice. Since 1996 the observatory meets high international standards and is a certified observatory of the international network INTERMAGNET. The observatory is equipped with two digital magnetometers with 3-axis ferromagnetic fluxgate sensors and with Bobrov type variometers. Data is uploaded to the Geomagnetic Information Node in Edinburgh. Variation measurements are completed weekly by absolute measurements of the geomagnetic field, carried out by a non-magnetic theodolite CARL – ZEISS equipped with a single-axis Bartington fluxgate sensor.
Earth tide observatories are located at three sites in West Bohemia (Skalná), Central Bohemia (Příbram) and North Bohemia (Jezeří). They are equipped with high resolution ASNS tiltmeters, but other types of tiltmeters are tested and compared as well, especially in the principal observatory in Příbram. That includes a new BTM-1 tiltmeter developed in our laboratory. The data is analyzed for tidal effects of the Moon, Sun and other extraterrestrial bodies, but mainly for other geological signals related to earthquakes, landslides, and general geodynamic activity of the Bohemian massif. The data is provided to the EPOS/CzechGeo web page of the Institute.