Hungarian Academy of Sciences

	Address:	H-9400 Sopron, Csatkai Endre u. 6-8
	Postal address:	H-9401 Sopron, Pf. 5
	Telepbone:	(36) 99-508-340, director: (25) 99-508-350
	Telefax:	(36) 99-508-355
	Director:	József ZÁVOTI, D.Sc.
	E-mail:	zavoti@ggki.hu
	Web site::	www.ggki.hu

 

 

Basic research in geodesy and geophysics, establishment and operation of geophysical observatories in the fields of seismology, geodynamics, geomagnetism, ionosphere and atmospheric electricity, support for institutions to solve problems in geodesy and geophysics, participation in international organizations and projects.

 

Geodesy: the field of interest includes geodynamic investigations for studying the structure of the Earth’s interior and global and local processes in the Earth’s crust, development of instruments and measurement methods for this purpose, modeling of the gravity field of the Earth. The Institute operates the Sopron Geodynamic Observatory. Research into mathematical methods to be used in earth sciences and geoinformatics helps this aim, too.

Geophysics: the main research field is "Earth electromagnetism", in a broad sense: from the investigation of electromagnetic structure of the solid Earth to the study of structure and processes of the near-Earth space. The following inter-related domains and their interactions are investigated: Sun, interplanetary field, magnetosphere, ionosphere, atmosphere, electromagnetic structure of the solid Earth (on near-surface-, crustal and mantle scales, especially beneath the Carpathian Basin and neighbouring regions), Earth's core. The research is based on observatory data (mainly on data of the Széchenyi István Geophysical Observatory near Nagycenk (Fig. 1), operated by the institute) and field measurements.

Seismology: its task is to run and develop the Hungarian seismological observatory network, to collect the recorded seismological information in the National Seismological Data Centre at the Budapest Seismological Observatory, to operate the all day seismological inspection for information of the public. The seismologists of the Institute determine the focal parameters and mechanics of earthquakes in Hungary and in its neighborhood, organizing macroseismic investigations of earthquakes felt in Hungary, update and archive the database of earthquakes recorded by Hungarian seismological stations and participate in international networks and projects. On this basis the research field covers the study of structure, dynamics and physical processes of the solid Earth. The charge of seismologists is assessment of seismic risk and vulnerability of different parts of the country and of high risk engineering structures.

 

Global and local geodynamic processes. These processes are studied using gravimeters, extensometers, tiltmeters and geodetic measurement methods. Results of investigations lead to considerations concerning the Earth’s internal structure and tectonic processes in the Pannonian Basin. Special emphasis is laid on the continuous increase of the accuracy of the measurements, on development and calibration of the instruments (Fig. 2) and on the investigation of environmental parameters effects on the measured data. The geodynamic research is based on data obtained in observatories in Hungary and in neighbouring countries within the framework of international cooperation, and on results of geodetic field measurements in different parts of Hungary. Especially, the geodynamic research carried out by multi-sensor observation techniques on areas prone to landslide is very important for the detection of interaction between landslide triggering processes. The results of these studies can be practically used in locating the sites of dangerous industrial objects and in prevention of disasters.

Modelling of the Earth’s gravity field. New methods led us to more reliable lithosphere density model in the Pannonian Basin. The results of local gravimetric measurements are used to study the local parameters of the gravity field; thus they contribute to scientific research connected to the preparation of the measurement of the new high-order levelling network in Hungary.

Deformation and movements of objects. In the frame of international cooperation new measurement and analysis methods are developed for the investigation of deformations and cyclic movements of dangerous industrial objects, building, bridges, etc. and for the health and seismic risk assessment of structures.

Mathematical methods in geodesy. The wavelet transformation of the covariance function of signal and noise leads to new results in analyzing geodetic time series (e.g. that of pole wandering). The transfer characteristics of trigonometric filtering are studied, too. The application of time series analysis in geodesy gives an answer to the question about the future trend of geologic processes. The Gauss-Jacobi combinatorial adjustment is applied to solve the 3D transformation problem with 7 parameters, and it is also demonstrated that the combinatorial algorithm gives the same solution as the conventional linear Gauss-Markov model.

Near-Earth Space Physics. Long- and short term variations of solar activity, solar wind parameters and geomagnetic activity (Fig. 3). Modeling and observation of solar wind – magnetosphere – ionosphere energy coupling. Effects of near-Earth space to the global changes and human activity, often referred to as space weather and climate. Study of magnetospheric waves (ULF, VLF), field line resonance, upstream waves. Contribution to the global geomagnetic field modeling. Ionosphere – neutral atmosphere coupling. ELF wave propagation in the Earth-ionosphere waveguide. Electro-optical emissions in the upper atmosphere. Climate change-related ionosphere- and atmospheric electricity studies. Maintaining networks and participating in coordinated campaigns of magnetic, telluric, whistler, ionosphere sounding, atmospheric electricity, radiowave propagation and Schumann-resonance measurements (such as SEGMA, OERSTED, CHAMP, INTERMAGNET, SWENET, EUROSPRITE, etc.)

Solid-Earth Electromagnetism. Investigation of electromagnetic structure of the Earth beneath the Pannonian Basin and neighbouring areas by means of geo-electromagnetic methods at various scales: (1) from crustal to mantle structures (lithospheric and asthenospheric investigations) by means of magnetotellurics, geomagnetic deep soundings, tellurics; (2) near-surface geoelectric-electromagnetic investigations, in order to be able to get improved images of subsurface (with various, e.g. environmental applications). Research includes both theoretical and practical approaches, possible bio-geo interactions, and also Near-Earth Space Electromagnetism aspects.

Development of the national seismological network. (Fig. 4) The aim of this activity is to record at high level of resolution the seismic events of the Pannonian basin and in the same time to observe all the significant earthquakes worldwide. For this purpose beside the already existing short periodic stations a network of very broadband instruments is also in operation. The records of newly installed very broadband seismographs through real time data transmission are available for interested institutions within the country and worldwide. The national data centre at the Budapest Seismological Observatory collects all the observed in the country seismological data, accomplishes automatic event recognition service.

Study of the Earth rotation from geological to sub daily time-scale. The aim of this research field is to investigate temporal variations of geodynamical properties of the Earth and development of the Earth-Moon system due to tidal friction. In the frame of this topic in decadal – sub daily time-scale the influence of seismicity, geomagnetic phenomena, and meteorological processes on Earth rotation vector is also investigated.

Focal mechanisms. Having completed the database of Hungarian earthquakes areas will be identified where the type of the earthquakes is similar. Having determined the moment tensors of these areas, the directions of stresses will be obtained which govern recent tectonic processes in the Pannonian Basin.

Seismic tomography is applied and developed for a better knowledge of the three dimensional structure of the Pannonian Basin. Using seismographic records, the velocity distribution is determined in the Earth’s crust and upper mantle together with the velocity contrasts. With the use of complete waveform inversion the determination of hypocenters and focal mechanisms of earthquakes can be made more accurate in order to achieve a better idea about the tectonic conditions in the Pannonian Basin.

Seismic risk. Beside the traditional probability based seismic risk evaluations it is now necessary to compute synthetic seismograms for the vicinity of potential earthquake foci and for endangered settlements in their area to obtain more reliable seismic risk values. A two- and three-dimensional pseudo-spectral method is applied for the computation of synthetic seismograms, which allows taking into account local tectonic and geophysical conditions.

University of Western Hungary: courses in environmental sciences and courses for environmental engineers, courses in basic mathematical subjects, advising students in preparing their theses for a degree, committee-work at exams for a final degree and at doctoral exams, advisory work in preparing doctoral theses, participation in committees for state exams. Lorand Eotvos University of Sciences and University of Miskolc: general lectures, lectures in doctoral schools, giving practical lessons for developing skills of students, advisory work for students preparing their final written presentation, advisory work in preparing doctoral theses. Babes-Bolyai University of Sciences in Kolozsvar: teaching subjects in general and applied geophysics. BMGE: PhD exams and doing work as opponents in the PhD procedure. Pal Kitaibel Environmental PhD school for geo- and environmental sciences. Giving lectures to PhD students and making exams for them at the Vienna University of Technology.

International University Bremen, Institute of Atmospheric Physics Prague, Beijing Institute of Geology and Geophysics, University of L’Aquila, Space Research Institute of Austrian Academy of Sciences, Graz University of Technology, Université Neuchatel, Reading University, Meteorological Department, Anglia, Massachusetts Institute of Technology, Parsons Laboratory- USA, Tel Aviv University – Izrael, Vienna University of Technology, Université Paris Sud, CETP, GeoResearch Center Potsdam, Observatoire de Paris, Teheran University, Stuttgart University, Darmstadt University of Technology, Institut of Oceanography of the Russian Academy of Sciences, Usikov Institute for Radio-Physics and Electronics National Academy of Sciences of the Ukraine, Kharkov. IAG Comm V: Earth Tides, SC3 Working Group ’Fundamental Parameters’, IAG SG 2.2 ’Forward Gravity Modeling Using Global Database’. IAG SC4.2 Working Group ’Monitoring of Landslides and System Analysis’.COST 296, WP1.4, 2.2 ’Mitigation of Ionospheric Effects on Radio Systems’, COST 625, COST 721, COST P18 ’The Physics of Lightning Flash and its Effects’.

The most of Hungarian seismological stations through the Seismological Observatory are directly connected to seismological services of European countries and vice versa the Hungarian seismologists are using permanently data of foreign observatories. Scientists of the Seismological Observatory are participating in many international projects, initiates and conducts bi- and multilateral initiatives, organizing international workshops and conferences.