The Journal of the Association:
MAGYAR GEOFIZIKA (HUNGARIAN GEOPHYSICS)
After six years of activity, in 1960 the Association started to publish a modest quaternary, of what we are editing its 53rd volume. The aim of this journal was twofold: to promote the technical results published in the foreign-language literature, and to broaden the publication possibilities of the members. Now its pages are heralding the news and records of the Association's social and official life, giving forum for members' opinions, as well as publishing several expert papers per number in Hungarian, with English content.
As elected by the General Meeting for term of three years, the managing editor is Tamás Bodoky. Editorial board: István Baráth, Kristóf Kakas, László Lenkey, Gábor Pethő, László Szarka, and László Verő.
Here we list the contents and some abstracts in backward order. According to our wish, the journal and this portal will serve the membership and the foreign/domestic reading public in synergetic mood. The printed version (the journal of 'MAGYAR GEOFIZIKA') will be made for traditional readers, while this electronic version (the homepage itself) could produce pages with quick service, with colour (and less expensive for our budget) ... see later the columns of news and coming events .
Volume 50, No.2
Foreword of the Editor 53
MGE (Association of Hungarian Geophysicists) News 54
EAGE (European Association of Geoscientists and Engineers) News 57
Study of the geophysical data along the CEL08 deep seismic lithospheric profile - J. Kiss 59
Determination of natural gamma spectra and gamma spectra excited by termic neutrons using bismuth–germanat scintillometers at well logging - F. Henézi, L. Kollár, A. Lovas, Z. Vízvári 75
Selected passages of the history of Hungarian geophysics VI - Z. Szabó 82
Moon New Year’s Day in the Eötvös Institute with Mongolians and Hugarians who worked in Mongolia, and those what occure to us in connection with that - L. Nemesi 89
News and Reports 94
Ferenc Szerecz 100
Volume 50, No.1
Foreword of the Editor 1
MGE (Association of Hungarian Geophysicists) News 2
Inversion of magnetotelluric measurements taking the static shift into consideration - E. Prácser, J. Kiss 18
Piezomagnetic modelling of earthquakes - T. Lipovics 29
The 1st Meeting of Young Hungarian Geophysicists - K. Molnár 41
News and Reports 42
Gyula Dankházi 47
László Szabadváry Dr. 49
Aladár Balogh 51
Imre Szabó 52
Volume 49, No.4
Year of Planet Earth
Gravity measurements along the United Hungarian Levelling Network (EOMA) - G. Csapó 138
Structural evolution of the Szeghalom metamorphic dome on the basis of petrological and seismic data - M. Tóth T., Redlerné T. M., Kummer I. 143
Selected passages of the history of Hungarian geophysics V - Z. Szabó 152
News and Reports 158
Sándor Nagy 162
Lajos Szilágyi 164
Volume 49, No.3
MGE News 101
Comparison of the Hungarian gravity base networks and their reference systems - G. Csapó 105
The effect of different 2D geometries on the numerical models of thermal convection in the Earth’s mantle - M. Herein, A. Galsa, L. Lenkey, B. Süle 111
News and Reports 124
Dr. Attila Meskó 129
Volume 49, No.2
Foreword of the Editors 65
MGE News 67
Looking for the Hopkinson effect, i.e. the significant susceptibility increase near Curie temperature in the Pannonian basin - A. Ádám 68
On the convection in the Earth’s mantle - A. Galsa, L. Lenkey, B. Süle, M. Herein 75
Magnetic surveying for archaeological prospection in Porolissum - J. Petrovszki, T. Lipovics, L. Lenkey, M. Pethe, E. Ferencz, M. Herein 88
Answer to remarks of R. Stomfai to paper of T. Ónodi (Vol. 49, No. 1; Vol. 48, No. 2) - T. Ónodi 95
News and Reports 96
Volume 49, No.1
MGE News 1
Different characteristics of the correlation of two sets of data - F. Steiner, B. Hajagos 27
Adopting polylogarithmic functions for engineering practice - T. Ónodi 34
Selected passages of the history of Hungarian geophysics IV - Z. Szabó 45
Yotta. Remarks to paper of T. Ónodi: Earth–Moon system and quantity of tidal friction (Vol. 48, No. 2) - R. Stomfai 52
News and Reports 53
Volume 48, No.4
Report on the Activity of the Association, Years 2006 – 2007 – A. Pályi, secretary general
News on the Senior Committee – Etelka Aczél
Global gravity anomalies of Moon, Venus, and Mars, quantitative interpretation of four Martian gravity anomalies – K. Kis, P. T. Taylor, S. Puszta, B. Toronyi, G. Wittmann
The missions Lunar Prospector, Magellan and Mars Global Surveyor recorded the topography and gravity field of the Moon, Venus and Mars, respectively. The tectonics of the Moon and the other two planets can be derived from these measurements on a global scale. The gravity data from the Mars Global Surveyor mission will be interpreted. The Martian gravity anomalies over the Alba Patera and Arsia Mons volcanoes, and the gravity anomalies over the Argyre and Isidis impact craters are interpreted by the Bayesian inference method. A finite vertical cylindrical model is used for this inversion method its radius, depths to the top and bottom of the cylinder are estimated by the Bayesian inference. The Laplacian probability density function is applied in the Bayesian inference. The optimum problem of the Bayesian inference is solved by the simulated annealing method. The estimated model parameter values for the Alba Patera volcano are: radius = 320 km ± 49 km, depth to the top = 6 km ± 4.8 km and depth to the bottom = 38 km ± 10 km; for the volcano Arsia Mons these values are: 182 km ± 42 km, 4 km ± 4.7 km, 57 km ± 15 km; and for the impact craters Argie: 355 km ± 59 km, 25 km ± 5 km, 31 km ± 8.3 km; and Isidis: 336 km ± 57 km, 21 km ± 5 km and 38 km ± 9 km, respectively. Inversions of the gravity anomaly data, however, shows a greater lower depth over these volcanoes. These greater depths are probably an indication of the mantle plumes that produced the volcanoes.
Vibratory source signal analysis with the help of geophone signals – P. Scholtz
The latest high resolution, high productivity reflection seismic measurements require the knowledge of a more accurate vibratory output signal estimate. In this case the harmonic distortion produced correlation noise can be removed or treated as signal. To support this idea a wavelet transformation and frequency domain division based processing method is shown, where the unknown convolution (filtering) effects on the propagating seismic waves are removed and in case of vibratory signal generation the amplitude and phase relations of the source can be studied.
In an experimental measurement, carried out in the style of the reflection seismic measurements of the future, the direct arrivals recorded by the surface planted geophones are helping the seismic source signal analysis. By studying the data it is proved, that the proposed analysing method has removed the filtering effects, hence the relative amplitude and phase behaviour of the harmonic components — contained in the distorted source signal — can be estimated. The vibrator mounted accelerometer signals and the calculated ground force signal are compared to the geophone based relative components. This analysis provides data on the quality of the new source signal estimates. The results can be utilised in the pre-processing of vibratory seismic data.
News and Reports
EM induction workshop at the IUGG 2007 general assembly (Perugia, Italy) – L. Szarka
Centenary events at the Geophysical Institute –Zsuzsanna Hegybíró
First National Conference of Geosciences Student Groups
Youth Contest named Lorand Eötvös at Celldömölk
Volume 48, No.3
The centennial story of the Eötvös Loránd Geophysical Institute – T. Bodoky
Reinterpretation of CEL07 deep seismic profile – K. Posgay, A. Cs. Kovács, R. Csabafi, T. Bodoky, E. Hegedűs, T. Fancsik, B. Rigler
The deep seismic profile, CEL07 was shot in the year of 2000 in the frame of the CELEBRATION 2000 seismic experiment. The authors reprocessed the CEL07 data. The reprocessed dataset provides new information about the geologic structures crossed by the profiles. Referring to those structures the paper outlines the present ideas developed in the last few years and completes it by the results of CEL07’s new interpretation.
From the profile running SW of the Penninic outcrops of Kőszeg–Rechnitz mountains and its neighbourhood it is possible to infer a westward continuation of the Kőszeg–Rechnitz uplift which can be followed towards the Tauern tectonic window. That continuation (or crest) is indicated by an ascent of 4–6 km of the iso-velocity lines in the upper crust. Those iso-velocity lines in the upper crust also rise at the Bohemian massif, at the Paleozoic uplifts known from drillings along the Balaton Line as well as at the metamorphic basement of the Tisza unit.
The iso-velocity lines of the upper crust are getting deeper below the Northern Calcareous Alps, below the covered continuation of the Transdanubian Central Range as well as below the Mesozoic parts of the Sava unit.Along the profile, below the Bohemian massif the crust-mantle boundary can be found in a depth of 35 km, below the Central Alps that is 35–38 km and below the Pelso and Sava units it is expected to be 27–28 km. SE of the Mid-Hungarian Line in the middle crust the iso-velocity lines suddenly rise, thus it seems to be likely that the Tisza unit differs from the other parts crossed by the profile considerably. In line with the velocity jump here the depth of the crust-mantle boundary may be even less, i.e. about 25 km.
Estimation of hydraulic permeability based on geophysical measurements – L. Zilahi-Sebess, T. Fancsik, I. Török, A. Cs. Kovács
In the past decade ELGI took part in the geological site investigation of a low and intermediate radioactive waste deposit. During that numerous geophysical methods were applied. Generally the geophysical measurements are used for outlining a structural geological picture and for classification of rocks according to the geomechanical properties, which usually can not be linked directly with hydrogeological properties. As a result of evaluation commonly the distribution of the physical parameters with some geological explanation are reported which frequently are not the proper information for geologists. The aim of this study is to bring closer geophysical evaluation to the useful parameters of geology and in the same time to show the role of well logging in the communication between hydrogeological evaluations based on data originated from borehole and on interpretation of surface geophysical measurements. The hydraulic permeability of rocks is an important factor in the environmental research such as a site investigation of a radioactive waste repository. According to the observations the relation between electric resistivities and seismic velocities measured on the surface is very similar to that based on well logging measurements (electric resistivity and sonic velocity). Experiences show that the shape of permeability curves based on well logging is approximately similar to the shape of the seepage factor curves got from hydrogeological tests in short time (early time test). It follows from the foregoing that the empirical relation based on well logging data normalised to hydrogeological ones might be applied to the parameters got from surface geophysical measurements, too, in other words, information for the possible hydraulic permeability can be gained from surface geophysical measurements, too. There is only one restriction, i.e. that the permeability estimation based on surface geophysical methods may be valid only for the investigated blocks so the hydraulic permeability has to be considered as a function of a certain primary porosity.
Investigation of the pattern and long-term variation of the gravity field by gravity methods – G. Csapó
The knowledge of the actual figure of the Earth is an important problem from many scientific and practical aspects. There is a close relationship between the figure of the Earth and its gravity field therefore the basic aspect of the investigations is the ambition to study the structure of the gravity field in detail. The author deals with the methods of investigation with special respect to the revival of field torsion balance measurements in Hungary after more then 40 years interruption. In the second part of the paper, the assumed long term regional and local variations of the gravity field in Hungary are discussed. The discussion is based on repeated absolute gravity observations.
Detection of near-surface contamination with 2D and 3D geoelectrical methods: case histories – Zs. Nyári, B. Neducza
Non-invasive detection of near-surface contaminants is an important step during the process of environmental diagnostics. Applying such method the delineation of the contaminant will be possible without the risk of the contaminant’s vertical spread. Geoelectical surveying methods are useful for these tasks when there is significant conductivity contrast between the contaminant and its geological surroundings. This paper introduces the possibilities of application different types of 2D and 3D survey methods at two test sites. All the results were validated by independent geological and geochemical research.
Advanced Seismic Acquisition and Processing (ASAP): introduction of an EU financed international research project – P. Scholtz, Zs. Nyári
We were notified by a letter received from the EU in the Summer of 2006 that application for a common project was successful within the 6th Framework Programme (FP6) Human Resources and Mobility (HRM) Activity, Marie Curie Actions, Marie Curie Host Fellowships for the Transfer of Knowledge (ToK) Development Host Scheme. The granted project has the Eötvös Loránd Geophysical Institute (ELGI) as the leading (host) institution; Schlumberger Cambridge Research (SCR) and WesternGeco are the industrial partners. This form of support, as the long title partly suggests, is organised around a research topic and provides opportunities for mainly European scientists, but also for researchers from all around the world to enhance their knowledge by the help of a host (ELGI) and its partners. Furthermore it also enriches the host by the results of the research project. The research topic aims to achieve new developments in the field of seismic acquisition and processing (see title). The project lasts for 3 years and we have almost one million euro to cover the cost of employing foreign researchers (maximum 2 years), the visiting scientist of partners (at ELGI) and the outgoing researchers of ELGI (visiting the partners). The budget provides the background for the project costs as well.
In this report we summarise the premises, introduce the partners, the research topic and highlight some research results from the first year of the project.
The GEOMIND geophysical metadata model - L. Sőrés
The mass, diversity and heterogeneity of geophysical datasets are often serious obstacles, that restrain the society to make use of geoscientific information. In the last decade the Eötvös Loránd Geophysical Institute gained lots of experiences in the management of large datasets, and realised the need of international harmonisation. The work has started, and with the contribution of 14 European organisations a new geophysical metadata profile was created. It is an extension of the internationally accepted ISO19115 metadata standard. The paper gives an overview of the new standard, and an implementation example for a geophysical dataset.
Selected passages of the history of Hungarian geophysics, part 3 - Z. Szabó
News and Reports
Anniversaries in the Hungarian geophysics –International Geophysical Year(s) – L. Szarka
50th anniversary of the Nagycenk Geophysical Observatory – L. Szarka
Volume 48, No.2
Palaeomagnetism of the sediments of Lake Balaton - P. Márton
We tested the remanence of two short sediment cores of Holocene age from Lake Balaton for the secular variation of the geomagnetic field. IRM runs and S-ratio values point to a ferrimagnetic phase (magnetite, maghemite) as the dominant magnetic mineral present in the sediment. On the Wohlfarth–Cisowski test the behaviour is interacting single domain but there is an abundance of superparamagnetic particles as well as shown by the high degree of viscosity on AF-demagnetisation. Combined with linearity analysis the latter was applied to separate and identify those remanence components, which were thought to have been imprinted by the geomagnetic field. After disposing of the severly outlying remanence directions, the mean direction in both cores agrees well with the local direction of the axial dipole field but the individual directions do not seem to follow any regular course expected for the secular variation.
Water lilies and the gravity field - J. Kiss, E. Szalma
When the gravity lineament map of Hungary was prepared its results were compared with other, i. e. geophysical, geological and botanical data as well. At joint study of hydrobotanical and geophysical data we were inclined to think, that there was a surprising correlation between them…
Our studies resulted in pointing out that the development of hydrobotanical habitats and their characteristic species are unambiguously determined by the presence of ground- and surface-waters and by the ratio of their mixing. While the attributes of the gravity field (for example gravity lineaments) can indicate hidden geological structures, along which old water belonging to larger depths can ascend to the surface and provide life conditions for water lilies.
Earth–Moon system and quantity of tidal friction - T. Ónodi
The life cycle of corals is influenced by the moonlight and tide motion and by the same way by the day and night cycle and seasons. Consequently the length of year and month can be defined on fossil coral reefs.Based on measurement of laser-mirror on the Moon’s surface, the orbit of Moon is about 38 mm higher each year . The slowing rotation of Earth is also detected by modern time measurements , .
The tide force accelerates the Moon and slows down the Earth’s rotation. As the angular momentum is a conserved quantity, the sum of angular momentum of Earth’s rotation and the angular momentum of the Moon’s orbit is constant. The cumulative energy of the Earth–Moon system is continuously decreasing. The “lost” energy converts to other energy forms, as tidal wave, deformation, grinding and finally thermal energy. The quantity of this energy conversion is comparable with the energy consumption of the industry, consequently even total exploitation of tidal energy could not substitute the fossil energy sources.
News and Reports
On the SPWLA Budapest Chapter – J. Császár
Visiting the Paks Nuclear Power Plant – Ms. Mariann Török-Sinka
Year 2006 decorating event with commemorative medal 'Pro Geophysica' of ELGI – I. Baráth
Volume 48, No.1
Finite element modelling of penetration electric sonde - D. Drahos, A. Galsa 22
Fossile geotherm estimation of spinel peridotite xenoliths from Tihany (Bakony–Balaton Highland Volcanic Field) based on CO2 fluid inclusions - M. Berkesi, K. Hidas, Cs. Szabó 31
Volume 47, No.4
Foreword of the Editor 121
OTKA (Hungarian Scientific Research Fund) 123
Geomagnetic pulsations, interplanetary space, magnetosphere and ionosphere during the 11. 08. 1999 solar eclipse - J. Verő, P. Bencze, A. Csontos, B. Heilig, J. Szendrői, B. Zieger 125
Study of heat production of Neogene volcanic rocks from Hungary - L. Lenkey, G. Surányi 128
Atlas of the present-day geodynamics of the Pannonian basin: Euroconform maps with explanatory text - F. Horváth, G. Bada, G. Windhoffer, L. Csontos, E. Dombrádi, P. Dövényi, L. Fodor, Gy. Grenerczy, F. Síkhegyi, P. Szafián, B. Székely, G. Timár, L. Tóth, T. Tóth 133
New trends in magnetotellurics - L. Szarka, A. Ádám, M. Kis, I. Lemperger, A. Novák, S. Szalai, Cs. Ubránkovics, J. Verő, V. Wesztergom, I. Fejes, J. Kiss, A. Madarasi, E. Prácser, L. Sőrés, G. Varga, Z. Nagy, P. Zahucki 138
Development of joint inversion methods for investigations of 2D and 3D near-surface structures - T. Ormos, Á. Gyulai, G. Pethő, E. Turai, A. Daragó 144
Geo-hydrodynamics: fluid dynamical phenomena in the Earth’s interior - L. Cserepes, P. Dövényi, A. Galsa, L. Lenkey, P. Mihálffy, B. Süle 147
Processing and interpretation of the magnetic measurements of Ørsted - K. Kis, G. Wittmann 152
Comprehensive investigation of recent and paleoearthquakes occurred in the Carpathian Basin - Gy. Szeidovitz, K. Gribovszki, Z. Bus, G. Surányi, E. Győri, Sz. Leél-Őssy, P. Scharek 155
Processing of reflection seismic measurements with increased spatial sampling - O. Ádám, P. Scholtz, Zs. Nyári, L. Gömböcz 160
Geo-electromagnetism - J. Verő, A. Ádám, P. Bencze, J. Bór, A. Koppán, K. Kovács, I. Lemperger, D. Martini, F. Märcz, A. Novák, T. Prodán, G. Sátori, S. Szalai, L. Szarka, V. Wesztergom, B. Zieger 166
Inverse methods in hydrogeology - P. Szűcs, A. Tóth, B. Zákányi, T. Madarász 169
Full waveform inversion of Hungarian earthquake data for hypocenter coordinates and focal mechanism - Z. Wéber 173
Post Badenian horizontal movements in the Pannonian Basin: a complex paleomagnetic-microtectonic study - E. Márton, L. Fodor, I. Magyar 178
Study of the environmental effects using magnetic characteristics of sedimentary rocks with Fe-sulphides - P. Márton, E. Márton, E. Babinszki, L. F. Kiss 183
Volume 47, No.3
News from the Associations
Reports on the Zalakaros conference — J. Császár and Ms. Zsuzsanna Hegybíró
News from the Senior's Club — Ms. Etelka Aczél
Visit of the IAGA first secretary to Sopron and Budapest — L. Szarka
Year 2006 Agocs price winners: dr Erzsébet Győri and dr. Géza Wittmann — K. Kis
Influence of the Internationale Erdmessung conference held at Budapest in 1906 on the progress of geodesy and geophysics — L. Völgyesi, J. Ádám, G. Csapó, D. Nagy, Z. Szabó, G. Tóth
The Internationale Erdmessung, predecessor of the International Association of Geodesy, held its General Meeting 100 years ago from September 20-28, 1906 at the Hungarian Academy of Sciences (MTA) in Budapest. This program was of historical importance for the discipline because it was here where the scientific community learned for the first time about the research activity of Loránd Eötvös and about the capability of the torsion balance, named after him. After the visit of a delegation to the field survey being carried out around Arad, a petition was drafted to the government and presented by Sir George Howard Darwin. As a result, beginning in 1907 for three years the government increased the financial support to Eötvös’s research 15-fold. This provided greatly to the further development of the instrument. Due to this development, a revolutionary progress took place in gravity research, whose bountiful influence can be felt even today. The Eötvös torsion balance measurements were mainly used in searching for mineral resources. However the data obtained even today is priceless for information which can be used in geodesy. In Hungary in the last century more than 60000 torsion balance measurements were made, and until the 1940s practically on every continent the Eötvös torsion balance was one of the most frequently and most successfully used instruments used in geophysical surveys. In this paper the importance of this event in geodesy and geophysics is outlined and its effect on the scientific research is briefly discussed.
About of the establishing of the Eötvös Lorand Geophysical Institute — T. Bodoky, Z. Szabó
Beliefs and facts on the establishing date of the Institute. Early years of the torsion balance laboratory of baron Eötvös, from which the oldest geophysical prospecting institution was originated. The newly accepted date: 1907
Volume 47, No.2
News from the Associations
Spectral analysis of the magnetic measurements of the Ørsted, CHAMP, and SAC-C satellites –K. Kis, G. Wittmann
The power density spectra of the total magnetic measurements of the Ørsted, CHAMP, and SAC-C satellites are obtained by the Yule–Walker and Burg methods. Data series of July 28, 2001 and August 16, 2001 are analyzed. The analyzed data series have been regarded to autoregressive process and its order is determined by the finite prediction error and information criterion of Akaike. The DC and low-frequency range are eliminated by the application of Gaussian high-pass filter (transmitted wavelength range < 2320 km). 2132 km, 1323 km, 463 km, and 339 km wavelength peaks can be determined from the power density spectra of the Ørsted measurements; 2115 km, 1161 km, 891 km, and 280 km wavelength peaks are characteristics for the CHAMP power density spectra. These wavelengths are obtained from the measurements of July 28, 2001. A different peak at 91 km is obtained from the SAC-C measurements. The other peaks obtained from the SAC-C measurements are at 2160 km, 230 km, and 91 km wavelengths.
Neural-network modelling of earthquake occurrences – B. Bodri
Changes in seismic activity distributions may occur during the process of preparation of large earthquakes, and such changes possibly are the most reliable long-term earthquake precursors examined to date [Molchan, Kagan 1992; Eneva, Ben-Zion 1997a]. In this work, the results of a neural-network modelling of the occurrence times of large (M ≥ 6.0) earthquakes in two considered regions are presented. Three-layer feed-forward neural-network models were constructed to analyse and predict earthquake occurrences. Numerical experiments have been performed with the aim to find the optimum input set configuration which provides the best performance of a neural network. It was possible to reach sufficiently good correspondence between predicted by the model outputs and known from experience outputs within the limits of given error thresholds, only when the input parameter set contained seismicity rate values for different magnitude bands (when such data appeared representative enough) and also for more than one time intervals between large earthquakes. The specific structure of the network input generates the question of whether this configuration has some relationship to the physics of strain accumulation and/or release process. The remarkably good predicting power of the constructed neural networks suggests the usefulness of the application of this tool in earthquake prediction problems.
Gravity lineament map of Hungary: first results – J. Kiss
When compiling geological or structural maps of the country it is a frequently arising question what kind of geological process can be connected to lithological changes known from borehole cores? How can we catch the real direction of a tectonic structure, or a thrust fault and what are the consequences of tectonic movements? To answer those questions one may turn to the geophysical data providing information about the deep geological structures. There are a lot of different geophysical methods and if no 3D seismic data are available on the task area then also the gravity database of Hungary may turn out very useful. To prove that this paper is going to present some „fantasy-incentive” gravity maps and filtering processes and as a result some gravity lineaments which indicate lithological changes or tectonic structures if eligible density-contrasts are connected to those.
Lorand Eötvös and the figure of the Earth – Z. Szabó
NEWS AND REPORTS
2nd International Conference for Environment and Engineering, Wuhan, China – report by L. Szarka
Book reference by L. Szarka: "Near-Surface Geophysics, Ed.: D. K. Butler, SEG, Tulsa, 2005
Volume 47, No.1
News from the Association
Report on the annual meeting of the Association – 21st April, 2006 — A. Pályi
When alligators spreaded out…(subjective report on the Youth Meeting) — Zs. Hegybíró
Wreath laying ceremony at the Eötvös grave — K. Kakas
New results about the geophysical application of the electromagnetic field due to electric power lines — E. Takács, G. Pethő
As it has been shown by using numerical forward modelling and experimental field measurements, the electromagnetic fields due to power lines can give geological information even in the vicinity of power lines. For the localisation of relatively near-surface lateral inhomogeneities, we recommend to construct a map about the ratio of electric field components measured in two neighbouring sites, along profiles parallel to the power line. Such a survey can be carried out easily, quickly and cheaply, and by means of a very simple instrumentation. This method may become a useful complementary tool of traditional geoelectric soundings. The stratigraphic identification and the depth position of the inhomogeneities are given from related traditional measurements. It is possible to obtain a vertical resolution from several upper harmonics of the fifty hertz, too. For such a frequency sounding, a simultaneous measurement of the electric and magnetic field components is needed, which requires multichannel, frequency-selective voltmeters of higher sensitivity – possibly with digital recording — as well as additional theoretical and field examinations.
Screening environmental pollution by magnetic susceptibility — E. Márton, P. Márton
Combined field and laboratory measurements of magnetic susceptibility provide a quick and relatively inexpensive method for studying the environment both in virgin and in polluted states. Below are examples from our own practice as to how the susceptibility responds to each of the following factors acting on the environment: roadside pollution, mineral alteration, soil formation, fly ash deposition and urban traffic.
Interpretation of the CHAMP magnetic measurements over the Pannonian Basin — K. Kis, P. T. Taylor, S. Puszta, G. Wittmann, Hyung Rae Kim, B. Toronyi, T. Mayer-Gürr
Magnetic anomaly data recorded by the low-Earth orbiting geophysical satellite CHAMP are interpreted using both a forward and inverse method. These data are given in spherical polar co-ordinates. In the forward modelling interpretation the equations are given in Cartesian co-ordinates. For the inverse method we make a transformation between spherical and Cartesian co-ordinates by a single translation and rotation. Using the forward magnetic modelling program we modelled the CHAMP data from the central part Pannonian basin by a triangular body. The same model was also applied to our inversion method. The aim of inversion is the determination of the dimensions of the triangular prism model when the direction of remanent magnetisation known. The minimum problem of the inversion is solved by the simulated annealing method. Our results show that the source of the central anomaly, covering the Tisia Composite Terrane, is fragments of ophiolites and the crystalline metamorphic complex.
Selected passages of the history of Hungarian geophysics, part 2 — Z. Szabó
Volume 46, No.4
News from the Association
www.mageof.hu: the new wersion of the Association's homepage K. Kakas 142
Old gravity never dies: On the revival of torsion balance gravity measurements P. Szafián, G. Timár, F. Horváth p 146
The most successful geophysical tool in the first half of the last century was the torsion balance constructed by Loránd Eötvös. Several tens of thousands of data were measured with this instrument in Hungary. The high accuracy of these data makes them very useful in geological explorations even today. Unfortunately, a significant part of them can only be found in maps. In this paper a method is presented that can be used to transfer the analogue maps into a digital data base. With the help of this method 15 percent of the Hungarian torsion balance measurements has been processed.
Is it possible to get reflection from temperature differences? Zs. Prónay, E. Törös, R. Miskolczi p 152
In 2001 the authors were involved in the sonar measurements for investigating the morphology of the river bed in the vicinity of the location where the proposed DBR4 metro line (Budapest, Hungary) crosses the river Danube. The sonar sections showed some wave arrivals, which greatly surprised the specialists. Those phenomena were considered to be reflections from hot drawn springs. Calculations were carried out using data from the literature to prove that the different velocity and density caused by the different temperature of drawn springs and the water of the river Danube results in reflection of the acoustic waves, and that the sonar method is suitable for detecting drawn springs.
Despite calculations and modelling were proven that a temperature difference of 35 °C produces reflections with measurable amplitude, because of the law that ‘the Devil never sleeps’ physical experiments were conducted using the same instrumentation as for field measurements to demonstrate the potentialities of the sonar method to detect temperature differences
Application and advantages of a remarkable seismic refraction interpretation method by F. W. Hales I. Polcz p 158
The possibilities of receiving geothermic energy from the tunnels of the deep mine of Recsk (A case study) L. Göőz p 163
Postscript to the series of articles “The history of the Hungarian geophysical investigations” E. Aczél, A. Pintér p 165
Comments on “Geophysics and the Hungarian Academy of Sciences 1949–2005” (L. Szarka; Vol. 46, 3) G. Szongoth, L. Szarka, L. Zilahi-Sebess p 167
Comments on “Terrestrial impact craters” (T. Bodoky, Vol. 45, 1) R. Stomfai p 169
Volume 46, No.3
Congratulations to Pál Bencze, to Attila Galsa, and to Tamás Bodoky; p 85
News from the Association
Calculating the peak ground horizontal acceleration generated by paleoearthquakes from failure tensile stress of speleothems; Gy. Szeidovitz, Sz. Leél-Őssy, G. Surányi, T. Czifra, K. Gribovszki p 91
In the Hajnóczy and Baradla caves in Hungary some of the suitable speleothems are appropriate for estimating the upper limit of largest earthquakes that occurred in the last few ten thousand years. From the parameters of not damaged speleothems can be determined the upper limit of peak horizontal acceleration generated by paleoearthquakes during their formation.
In a laboratory the velocity of elastic waves, density and failure tensile stress of speleothem samples have been determined. Earthquakes have been recorded on the surface and 25 m deep in dolomite cavity by two identical type horizontal seismographs. The seismograms and the power spectra of the earthquakes recorded at the two stations were similar. The fundamental frequency and damping of speleothems have been measured in cavity. We took samples from dripstones of 5.1 m height in Baradla cave and determined their age.
It was established that these speleothems was not excited with a horizontal acceleration more than 1.14 m/s2 during the last 100 000 years. This value has to be taken into account in the estimation of earthquake potential of tectonical structures at the vicinity of the examined speleothems.
Phase transition at the Curie temperature and its geophysical consequences J. Kiss, L. Szarka, E. Prácser p 102
There are some interesting geophysical anomalies in the depth of the Curie temperature — that is 4–16 km in Hungary. First of them we would mention the deep magnetic bodies identified in this depth by spectral depth estimation of geomagnetic data. On the other hand, there are a lot of magnetotelluric crustal conductivity anomalies in the same range. On base of these arguments we suppose, that the anomalies are related partly to the magnetic phase transition, beyond the well-known physically realistic phenomena.
In this paper we try to review the magnetic phase transition just at the Curie temperature causing enhanced magnetic susceptibility (Hopkinson effect). This may be a good explanation of deep magnetic and crustal conductivity anomalies.
INTERMAGNET: a global geomagnetic network Geomagnetic-Aeronomic Group p 111
Global seismic monitoring L. Tóth p 121
Geophysics and the Hungarian Academy of Sciences 1949–2005; L. Szarka, p 127
News and Reports
Volume 46, No.2
Foreword of the Editors p 53
News of the Association p54
EAGE News p 55
The fulfilment of the law of large numbers in case of infinite asymptotic scatter by F. Steiner, B. Hajagos p 60
The law of large numbers in general sense can be fulfilled even if the asymptotic scatter is infinite.
Quick calculation of geostatistically distributed random numbers by B. Hajagos p 64
In some theoretical Monte Carlo-investigations as well as in some algorithms of the geophysical practice (e.g. using the surplus-error-method) the generation of many geostatistically distributed random numbers is needed. The quick calculation of the latters is given in the present article. In addition, for distributions characterized by odd a type-parameters (i.e., for Student-distributions characterized by even degrees of freedom) such quick algorithms are also given.
Investigations of the Eötvös Loránd Geophysical Institute in the field of geodetic gravimetry by G. Csapó p 66
Comments on “The history of well logging in Hungary” (I. Baráth, B. Kiss; Magyar Geofizika Vol. 45, Special issue) by B. Csath p 77
News and Reports p79
Volume 46, No.1
Report on the General Meeting of the Association, 22nd April, 2005 by A. Pályi p1.
Report on a traditional wreath-laying event at the tombstone of baron Loránd Eötvös by I. Baráth p18
Effect of varying crustal thickness on CHAMP geopotential data. by Taylor, T. Patrick; Kis, K.; von Frese, Ralph R. B.; Korhonen, J. V.; Wittmann, G.; Hyung Rae Kim; Potts, Larmie V. p19
Complex geophysical investigation along CELEBRATION-7 profile and the meaning of velocity anomaly. by J. Kiss p25
Feasibility of the total gravity variometer: solution of the equation of motion of the Stegena’s torsion balance. by S. Juhász p35
News and Reports
Year 2004 decorating event with commemorative medal 'Pro Geophysica' of ELGI by I. Baráth p44
Habilitaton of Mr. Tamás Bodoky at the Miskolc University by Zsuzsanna Hegybíró p48
Volume 45, No.4
MGE (Association of Hungarian Geophysicists) News 117
The first decade of 2000s: the era of gravity satellites - L. Földváry 118
Selected passages of the history of Hungarian geophysics - Z. Szabó 125
Volume 45, No.3
Foreword of the Editors 93
MGE (Association of Hungarian Geophysicists) News 94
The telluric conductivity anomaly at Magyarmecske: is it a buried impact crater? - T. Bodoky, I. Kummer, K. Kloska, T. Fancsik, E. Hegedűs 96
Lorand Eötvös the physicist and the geological exploration - Z. Szabó 102
Volume 45, No.2
MGE (Association of Hungarian Geophysicists) News 61
New measurements for the determination of vertical gradients - G. Csapó, L. Völgyesi 64
Simultaneous application of surpluserror sets of different magnitude for a simple 3-D model - B. Hajagos, F. Steiner 70
Porosity, permeability, fractal geometry - I. Elek 75
Hungarian geophysicists in Cuba - I. Polcz, T. Nyitrai, I. Szalay 78
News and Reports 86
János Tóth 90
Volume 45, No.1
MGE (Association of Hungarian Geophysicists) News 1
Optimal frequency limit for spectral filtering of dipole-dipole sections - Z. Tóth 21
History of the geoelectrical prospecting in Hungary II. - A. Ádám, Z. Nagy, L. Nemesi, E. Takács 25
Principles of the nuclear magnetic resonance (NMR) method introduced in water prospecting - P. Szemerédy 40
Terrestrial impact craters - T. Bodoky 51
News and Reports 56
János Renner 58
Elemér Ribi 59
István Tormássy 60