Plenary session
The proceedings of the Symposium developed within three sections:
– Geophysical investigations for energy resources and engineering geophysics
– Geophysical investigations for solid mineral substances
– The Earth's physics
– Exhibition of Apparatus and Posters
PLENARY SESSION
INTEGRATION AND SYNERGISM IN GEOPHYSICAL RESEARCH
Prof. Liviu Constantinescu, corresponding member of the Romanian Academy
Under the name of integrated interpretation (or "complex" interpretation)
geophysical data provided independently by different methods have long been
used for obtaining better results in solving a given problem. During the last
two decades or so the association of different geophysical techniques aiming
at the same goal has been made not only at the interpretative stage but from
the very beginning with a continuous interaction along the entire process of
data acquisition and processing.
This synergistic approach has led to remarkable results both in applied and
pure geophysics. Examples are mentioned for the first category and one important
case – that of plate tectonics – is discussed to some extent for
the synergism in planetary geophysics.
Key words: geophysics, synergism, integration, planetary geophysics, applied
geophysics.
THE EVOLUTION OF THE HETEROGENE HARMONIC 
MEDIA
THEORY:
APPLICATIONS TO D.C. ELECTRIC PROSPECTING METHODS
Acad. Sabba Stefanescu
The problem known in applied geophysics as "direct" or "of
models" in the case of d.c. electrometric methods, can be reduced to the
following question: If one has a punctual electrode O fixed on a ground
whose conductivity 
(M) is
a priori known in every point M(x, y, z) and if we inject through this
electrode a constant intensity current I what will be the value
(M) of the electric potential determined in M(x,
y, z)?
Admitting the validity of the electricity fundamental equations for tridimensional
media, as various as they can be (Maxwell), the classic solution of the mentioned
problem leads to the finding of adequate solutions for the equation with boundary
conditions.
This way to solve the inverse problem being very arduous, the author, using
the changing of variables:
came (1950) to the equivalent equations
where F(x, y, z) is an arbitrary function.
For 
,
and 
are
Newtonian potential functions, which permit the simulation by accurate calculation
in finite terms, of numerous concrete situations found
in d.c. electrometry.
Key words: electric prospecting, direct current electrometry, subsoil simulation,
heterogeneous medium, inverse problem solving.
THE IVth EXHIBITION OF APPARATUS AND POSTERS
Dorel Zugravescu, Scientific Secretary of the Scientific Section of Geology,
Geophysics and Geography of the national Romanian Committee of Geodesy and
Geophysics of the Academy of the Romanian Academy
The IV-th Exhibition of apparatus and Posters, in accordance with tradition,
reunites apparatus from earth's physics and applied geophysics fields – realized
within the Central Institute of Physics – Institute of Earth's Physics
and the Central Department of Geology – Institute of Geology and Geophysics.
The apparatus presented by the National Council for Water Management – Institute
of Meteorology and Hydrology constitute a première for the exhibition.
It was underlined that two of the present apparatus "Quartz strainmetter
equipped with magnetic displacement transducer" and "Water-tube tiltmeter
equipped with magnetic displacement transducer" are the results of the
Romanian specialists' cooperation with Japanese ones.
Key words: apparatus, apparatus for Earth's physics, apparatus for applied
geophysics.
Ist SECTION: GEOPHYSICAL INVESTIGATIONS FOR ENERGY RESOURCES
AND ENGINEERING GEOPHYSICS
Council Board: Dr.ing. Marius Visarion, Dr.ing. Constantin Calota,
Dr.ing. Vasile Chiscan, Dr.ing. Aurelian Negut, Dr.ing. Valeriu Varodin
THE STRUCTURE OF THE PANNONIAN DEPRESSION BASEMENT
IN ROMANIA (II. NORTHERN AREA)
M. Sandulescu, M. Visarion, P. Constantinescu, Ligia Atanasiu
Institute of Geology and Geophysics, Bucharest
North of the Crisul Repede river, the Pannonian Depression lies either directly
over the deformed structures assigned to the Inner Dacides, the Piennides and
the Median Dacides or over their post-tectogenetic covers. The integrated study
of geophysical and geological drilling data provides new data concerning the
constitution, structure and areal extent of these units by delimiting three
major blocks. The Salas horst, the Satu Mare graben and the Oas-Maramures block,
marked by crustal fractures. The carbonate and ophiolitic rock sequence, crossed
by the drilling at Babeni, crops out in a tectonic window due to the pre-Tertiary
erosion in inner Dacides units.
Key words: tectonic window, basement structure, seismic and gravity data, geological
section, drilling data.
GRAVITY REMARKS ON THE BUCHAREST-OTOPENI
HYDRO-GEOTHERMAL SYSTEM
V. Rosca, A. Nicolescu, Narciza Ligia Atanasiu
Institute of Geology and Geophysics, Bucharest
A gravity residual map of the Bucharest-Otopeni hydro-geothermal system lines
out anomalies of about 0.5 mGals. A study of the densities as determined on
core samples as well as simple geometrical models allowed some remarks on the
sources of these anomalies and their implications in the exploitation of the
hydro-geothermal resources present in the area.
Key words: geothermalism, gravity, Bucharest-Otopeni.
THE USE OF WELL LOGS FOR SOURCE ROCKS RECOGNITION AS WELL
AS FOR GENERATING AND MIGRATING CONDITIONS OF HYDROCARBONS
V. Negoita
Oil and Gas Research and Design Institute, Bucharest
The delimitation and characterization of potential source rocks by wireline
logs, the temperature and pressure conditions of organic matter evolution as
well as the expulsion of hydrocarbons from the source rocks to the permeable
rocks are the main topics in the paper.
Some examples using DRR, temeprature, pressure, radioactive and sonic logs
are illustrating the new improved methods for petroleum exploration and basin
analysis.
Key words: source rocks, organic matter evolution, hydrocarbon migration, well
logs.
THE SPECIFIC PROBLEMS OF BOREHOLE GEOPHYSICS FOR
THE WELLS DRILLED WITH POTASSIUM SALT MUDS
V. Negoita
Oil and Gas Research and Design Institute, Bucharest
Latterly, many wells on the Romanian territory have been using potassium
chloride drilling muds.
In such conditions the Spontaneous Potential, the Shallow Investigation Resistivity
Log and the Gamma Ray curves are recorded with significantly altered values.
The paper deals with some improvements in the choice of mud salinity, log recording
and well log interpretation. Several field examples finally illustrate the
results obtained.
Key words: Potassium-salt mud, well logging.
A METHOD FOR CHECKING UP THE PRESENCE OF THE
ANOMALOUS PRESSION ZONES
M. Saramet, C. Cranganu
"
Al.I.Cuza" University of Iassy, Faculty of Biology-Geography-Geology
The proposed method uses a computation relation based on the Vint/Varg ratio
as deduced from both sonic log and seismic data. Plotting this ratio versus
depth, one can distinguish the zones with anomalous pressions. The results
obtained were compared to data from geochemical log (in Crasna district), checking
up the validity of the proposed method.
Key words: interval velocity (Vint), argillaceous velocity (Varg), anomalous
pressions, sonic log, geochemical log.
AN ALTERNATIVE OF THE OIL AND GAS SEISMIC SURVEYS
IMPROVEMENT IN SOME ROMANIAN AREAS
G. Ionescu
Enterprise of Geological and Geophysical Surveys, Bucharest
We analyse the result obtained with the "Vibroseis" method in Romania
and other countries of the world and correspond material efforts.
We demonstrate that the "Vibroseis" method allows to obtain better
geological information than any other conventional method (dynamite), at the
same time saving some very important materials, thus justifying the necessary
efforts for purchasing vibration and complementary, necessary, electronic devices
to change the most conventional seismic crews into "Vibroseis" crews.
Key words: improvement of seismic surveys, vibroseis, dynamite, geological
information.
THE USE OF THE GENERALIZED RADON TRANSFORM
IN SEISMIC INVERSION
C. Stan
Enterprise of Geological and Geophysical Surveys, Bucharest
The problem of linearized inverse scattering is reduced to an integral equation
related to the causal generalized Radon transform. An asymptotic expansion
of the solution is obtained using the inversion procedure of the C.R.T. The
first term of the expansion is intepreted as a migration algorithm.
Key words: inverse scattering, generalized Radon transform, migration.
ON THE MYTH OF NONSEPARABILITY OF THE 3-D MIGRATION OPERATOR
V. Bardan
Enterprise of Geological and Geophysical Surveys, Bucharest
The 3-D migration of seismic data raises huge problems for both data handling
and storage requirements in the computer. There are computational advantages
to be obtained if the full 3-D one-step migration can be decomposed into two
cascaded 2-D migrations, this often being applied in practice. This paper analyses
the errors that appear when the one-step 3-D migration process is replaced
by the two-steps 3-D migration process.
Key words: 3-D migration, process, one-step, two-steps, 2-D migration, errors.
WAVELET PROCESSING WITH MINIMUM PHASE DESIRED WAVELET
V. Bardan
Enterprise of Geological and Geophysical Surveys, Bucharest
The purpose of the wavelet processing is to replace the wavelet on a trace
collection with a desired wavelet, defined by the geophysicist in the frequency
domain. The determination, in the time domain, of a minimum phase desired wavelet
is achieved by using the Hilbert discrete transform. This algorithm is very
instable. A new and stable algorithm is proposed.
Key words: wavelet processing, desired wavelet, minimum phase, algorithm.
SEISMIC DATA PROCESSING OF COAL SEAM WAVES
C. Cristescu1, V. Buruiana1,
I. Oancea2, V. Bardan1,
M. Barbu1
1 Enterprise of Geological and Geophysical Surveys, Bucharest
2Research Institute for Electrical Engineering, Bucharest
The paper presents the flowchart of data processing of the seismic data registered
in coal-seam (channel waves). Applicability of general algorithms is analysed
referring to the channel waves characteristics. The use of specific processing
algorithms is justified and described.
Key words: seismic data processing, coal-seam, waves, channel waves.
PROBLEMS OF SEISMIC TOMOGRAPHY WITH APPLICATIONS
TO THE PROCESSING OF IN-SEAM SEISMIC RECORDS
M. Barbu, C. Capra
Enterprise of Geological and Geophysical Surveys, Bucharest
The misuse of the therm "tomography" in seismic data processing
is discussed. After reviewing the major methods of the iterative reconstruction
of the underground properties, the algorithm and the corresponding program
for in-seam seismic recorded processing is described.
The possibilities of application of the iterative reconstruction methods are
estimated for their use in solving the other seismic problems.
Key words: seismic tomography, iterative reconstruction methods, seismic data
processing, migration.
RECORDING AND PROCESSING OF VERTICAL SEISMIC PROFILE (VSP)
I. Harabor, I. Chiscan
Enterprise of Geological and Geophysical Surveys, Bucharest
There are described the techniques for fields recording of primary data,
and the sequence of processing steps leading to the equivalent of an ordinary
seismic section: time, migrated or depth section.
VSP data allow extrapolation of the information from one well, both in the
vertical and in the horizontal direction.
Key words: VSP, modeling, corrections, migration.
SEISMO-GEOLOGICAL CONDITIONS AND THEIR IMPLICATIONS
IN THE HYDROCARBONS SEISMIC PROSPECTING IN THE
TRANSYLVANIAN DEPRESSION
I. Bucur, C.R. Popescu
Enterprise of Geological and Geophysical Surveys, Bucharest
The Transylvanian Depression is extensively studied in order to extend the
present productive fields.
On this occasion the seismic survey is confronted, in central-marginal areas,
with some problems connected with the surface seismo-geological conditions
or closely connected with the geological objective to be studied. The methods
approach some aspects, also offering solutions for avoiding some misinterpretations
of the subsurface images.
Key words: Transylvanian Depression, seismic surveys, surface and subsurface
seismic geological conditions.
GENERAL USE SOFTWARE FOR I.B.M. – P.C. COMPATIBLE COMPUTERS.
THEIR USE IN GEOPHYSICS
A. Vlad1, V. Constantinescu2
1Enterprise of Geological and Geophysical Surveys, Bucharest
2Institute of Geology and Geophysics, Bucharest
I.B.M. – P.C. Compatible Computers, both through their performances
(16 or 32 bits, comparatively large amount of core, fast and performing peripherals),
and through the great quantities of software available, offer facilities for
complex data processing. Here we describe the software packages, internationally
available, which are applicable in geophysical activities.
Key words: computers, software, packages, complex data processing, geophysical
information.
TENTATIVE EXPERIMENTAL SEISMIC WORKS
IN THE GODEANU MOUNAINS
C.R. Popescu, A. Zaharia
Enterprise of Geological and Geophysical Surveys, Bucharest
The paper presents the results of some seismic experiments achieved in the
Godeanu mountains with the aim to involve seismic into the solid mineral substances
prospecting. This possibility and the necessity of testing various methods
of wave generation and the study of an adequate experiment for the mountainous
area are underlined.
Key words: seismic experiments, solid mineral substances, mountainous area
THE AMPLITUDE ANOMALY AS INDICATORY OF THE
HYDROCARBONS PRESENCE IN POROUS-PERMEABLE MEDIA
F. Stefanescu
Enterprise of Geological and Geophysical Surveys, Bucharest
The decisive influence of the porosity and permeability on seismic velocity,
also the fluid content of the rock pores, which can potentially be a reservoir
in a trap, lead to dramatic changes of the acoustic impedance, thus influencing
the amplitudes of the seismic recordings.
The lithological changes present in these recordings, as well as the structural
context in which the amplitude anomaly has been noticed, lead to conclusions
which can increase the certainty degree concerning the hydrocarbon reservoir,
significantly augmenting the finding coefficient.
Key words: posority, permeability, acoustic impedance, amplitude anomaly.
ON THE PROSPECTS OF ACHIEVING A DEVICE FOR THE IN-MASSIF INVESTIGATION BY DYNAMIC
AUSCULTATION OF THE LIGNITE DEPOSITS
Micaela Alexandrescu1, R. V. Hobancu2,
M. Piso1
1Institute of Research, Technological Engineering and Mining Design for Lignite,
Craiova
2Research Institute for Electrical Engineering, Bucharest
Researches on the properties of rocks forming the lignite deposits point
to the conclusion – otherwise predictable – that there are marked
behaviour differences of these rocks in the massif compared with the laboratory
results. Notwithstanding the reduced elasticity of the lignite and adjacent
rocks, there are justified reasons to consider that it is possible to make
the research of these formations using the technique of direct signal receiving.
The installation of dynamic auscultation which will be realized is based, in
the main, on the controlled emission of elastic waves as impulses using al
excitator of original construction. The received impulses are submitted in
processing using the modal analyses which perform the logical filtering of
the information. We shall predictably determine in situ the velocity and elastic
compressional and shear waves attenuation as well as the special density maximum
displacement, these being the basic features for the evaluation of the properties
and the mining massif state.
Key words: dynamic auscultation, elastic waves, lignite deposit.
RESEARCH POSSIBILITIES BY SEISMIC METHODS OF THE
ROCK-MASS STATUS PARAMETERS IN THE LIGNITE MINES
I. Oancea, R. V. Hobancu, N. I. Pascovici
1Institute of Researches, Technological Engineering and Mining Designs for
Lignite, Craiova
2Mining Enterprise, Mehedinti
For the technical calculations which precede the design of the technologies
in the lignite mines, the rock properties of these deposits are the most important
elements. Experience showed that the results obtained by laboratory determinations
cannot be found in situ because of the so-called "scale effect".
The use of in situ methods breaks new ground. The application of the seismic
method by the direct transmission of the elastic waves emphasized the new possibilities
of determination, not only of the lignite properties but also, by original
interpretation methods, of the azimuthal anisotropy and the stress degree of
the rock-mass.
Key words: rock-mass status parameters by mining seismic.
ASPECTS OF GEOELECTRICAL, PROSPECTING OF COAL IN THE
NEOGENE SEDIMENTS OF THE VAD-BOROD DEPRESSION
Adalciza Badica
Enterprise of Geological and Geophysical Surveys, Bucharest
The geological research into the Vad-Borod Depression was aimed at obtaining
a detailed structural image at the Preneogene basement level, rendering evident
the tectonic elements which affect the underselecting compartments where coal
might exist.
The interpretation of the electrometric data shows different variation regimes
of the apparent resistivity with depth, this fact suggesting the existence
of compartments made up of lithologically differentiated rocks.
Key words: tectonic element, structural image, apparent resistivity, lithologically
differentiated rocks.
IInd SECTION: GEOPHYSICAL INVESTIGATION FOR SOLID MINERAL SUBSTANCES
Council Board: Acad. Sabba Stefanescu, Dr.ing. Radu Constantinescu,
Dr.ing. Paul Georgescu, Dr.ing. Mihail Ianas, Dr.ing. Dragomir Romanescu,
Ing. Ioan Stoica
SPATIAL DISTRIBUTION AND STRUCTURAL IMAGES OF THE BANATITES
FROM ROMANIA AS SHOWN BY MAGNETIC AND GRAVITY DATA
J. Aandrei1, Tr. Cristescu2, C. Calota3, A. Proca2, Dr. Romanescu1,
Doina Russo-Sandulescu1, A. Stefan1, M. Suceava2, M. Bradu2,
D. Hannich2, M. Albu2
1The Institute of Geology and Geophysics, Bucharest
2Enterprise of Geological and Geophysical Surveys, Bucharest
3University of Bucharest
The integrate interpretation of magnetic and gravity data within the context
of the petrophisycal information gathered by the authors and of the up-to-date
geological knowledge offers the possibility to find out the spatial distribution
of banatitic rocks intrusions of Romania. The structure of these intrusions
has been found in several characteristic situations with the help of gravity
and/or magnetic simulation models.
Key words: magnetics, gravity, petrophysics, banatites, geophysical simulation
models.
ALGEBRAIC RECONSTRUCTION OF THE VELOCITY FIELD BY CROSSHOLE
SEISMIC DATA APPLICATION TO THE PRAID SALT MINE
I. Balea, Mihaela Georgescu, V. Manj, Fl. Radulescu
Institute of Geology and Geophysics, Bucharest
The paper presents the algorithm used for algebraic reconstruction of the
velocity field. There are presented some results obtained by using the algorithms
upon the theoretical models and their application in improving the study of
the data yielded by the experiments carried out at the Praid salt mine and
Hercules spring – Herculane Spa.
Key words: crosshole, velocity field, raypath, tomographic technique, salt.
MERCUROMETRICAL RESEARCHES IN THE BAIA SPRIE-SUIOR AREA
D. Ioane, B. Crahmliuc, S. Scurtu, Anca Crahmaliuc,
Ligia Atanasiu, Carmen Dumitrescu
Institute of Geology and Geophysics, Bucharest
The mercurometrical researches carried out in the Baia Sprie-Suior area have
been conducted to study the applicability of this method for the prospection
of polymetallic mineralizations associated with Neogene volcanics within the
Baia Mare mining district. The authors have studied two different structural
and metallogenetical situations: outcropping polymetallic mineralization (Baia
Sprie) and deep polymetallic mineralizations (Baia Sprie-Suior). For a better
interpretation of the mercurometrical measurements, the authors also carried
out gamma ray spectrometry measurements and geochemical analysis, the data
being correlated with geological and geophysical information.
Key words: mercurometrical researches, polymetallic mineralization, the Gutai
Mountains.
DISCHARGE CURVES ANALYSIS IN INDUCED POLARIZATION SURVEY
Viorica Constantinescu, V. Constantinescu
Institute of Geology and Geophysics, Bucharest
The induced polarization data can be obtained in the time or frequency domain.
The authors used the facilities offered by an IBM-PC to process the time domain
data employing software package (Fast Fourier Transform, Fourier Smoothing
without the Fourier Transform, Cepstral Analysis, Correlation Analysis, etc.)
which are applicable in geophysical activity. The computation of the results
obtained in those domains improves the geological interpretation of the induced
polarization data.
Key words: induced polarization, discharge curve, time domain, frequency domain,
software package.
AUTOMATICAL DATA PROCESSING OF GAMMA-RAY SPECTRA
Fl. Radulescu, V. Serbu, S. Anastase
Institute of Geology and Geophysics, Bucharest
There is presented an automatical data processing of gamma-ray spectra obtained
by thermal neutron activation and gamma-ray spectrometry. This automatical
data processing was achieved using a closely-friend computer graphic system
and a built in radio-isotopes library created on a "CORAL" computer.
The system is provided with a module for inter-element interferation.
Key words: gamma-ray spectra, closely-friend computer graphics, inter-element
interferation.
ABOUT MODELLING THE GAMMA-RAY SPECTROMETRIC FIELD
EVIDENCED BY A AEROSPECTROMETRICAL ARESEARCH
Fl. Radulescu, Caterina Avramescu
Institute of Geology and Geophysics, Bucharest
This paper presents the algorithms and the results obtained by modelling
the radioactive gamma field.
In obtaining the aerospectrometric effect we considered: the area distribution
of the natural radioactive elements, the surface morphology and the detection
system used.
Key words: modelling, aerospectrometric effect, relief detection.
A STUDY REGARDING AN INTEGRATED SYSTEM OF DATA BASE AND
STATISTICAL ANALYSIS CONCERNING FIELD AND LABORATORY
GAMMA-RAY SPECTROMETRY
Fl. Radulescu, Elvira Ciucur, S. Craioveanu, Marioara Lemne, I. Tiepac
Institute of Geology and Geophysics, Bucharest
The increased number of data obtained from gamma-ray spectrometry measurements
demands the elaboration of a data-base system useful in the designing of gamma-ray
spectrometry as well as in the geological interpretation of geophysical data.
This paper deals with the data-base system, the data access and the statistical
process using stochastic grids. The data-base is achieved on a "CORAL" computer
with closely-friend computer graphics and may be expanded for processing different
types of geological and geophysical data.
Key words: data-base, gamma-ray spectrometry, closely-friend computer graphics.
CONTRIBUTIONS TO THE DEVELOPMENT OF REMOTE SENSING DATA
PROCESSING AND INTERPRETATION METHODS AS APPLIED TO GEOLOGY
V. Vajdea, C. Nitica, I. Popescu, Alexandra Marinescu,
D. Zorilescu, Anca Vajdea, Dana Fekete, Vl. Gancz
Institute of Geology and Geophysics, Bucharest
After a short description of the utilized remote sensing system, the main
contributions and results obtained in perfecting the aerial and spatial images
analogical and digital processing methods are presented, stressing first of
all the developing of software.
Key words: serial and spatial images, spectral bands, analogical processing,
digital processing, software, geosciences.
REMOTE SENSING APPLIED TO GEOLOGICAL RESEARCH WITH
EXAMPLES FROM THE ROMANIAN TERRITORY
V. Vajdea1, I. Popescu1, C. Nitica1, Alexandra Marinescu1,
D. Zorilescu1, Anca Vajdea1, Vl. Gancz1,M I. Baiu1, Viorica Popescu1,
T. Berza1, I. Seghedi1, I. Munteanu2
1Institute of Geology and Geophysics, Bucharest
2Institute of Petrological and Agrochemical
Researches, Bucharest
The paper presents the main results obtained by applying remote sensing in
solving some complex geological problems under the special physical-geological
conditions of Romania. Special attention has been paid to remote sensing contributions
in deciphering the structure and tectonics of the investigated regions.
Key words: remote sensing, multispectral images, linear element, circular structure,
fault.
CONSIDERATIONS ON THE INFLUENCE OF THE INDUSTRIAL NOISE
PRODUCED BY MINING ON THE RESULTS OF MAGNETOMETRICAL
PROSPECTING
D. Alexandrescu, Mioara Alexandrescu
Institute of Geology and Geophysics, Bucharest
The separation of the natural fields from the industrial ones is a difficult
problem because of the large variety of the electromagnatical sources with
the same frequency.
Our theoretical and practical studies have underlined the influence of mining
works on the results of magnetometrical prospecting because of the stationary
noise created by the buildings and even because of the transitory noise due
to the variation of the continuous and/or alternative current.
Key words: magnetometrical prospecting, natural and industrial fields, stationary
and transitory noises.
SOME EXAMPLES IN USING THE RANDOM NUMBERS
IN GEOLOGICAL MODELING
Fl. Scurtu
Institute of Geology and Geophysics, Bucharest
The paper presents the possibilities of using the Monte Carlo method in the
direct and inverse problems of geophysics. Examples on models simulating the
actual conditions of measuring the geophysical data (rugged topography of the
relief, remanent errors in the data to be interpreted) show that the method
works well but as concerns the obtainment of rather good geophysical solutions
and the generation of more equivalent models useful in the interpretation process.
Key words: geophysics, direct problem, inverse problem, aleatory numbers, numerical
approximations.
GEOTHERMIC METHOD APPLIED TO DETERMINE THE RISK
OF ORE SELF-IGNITION
B. Almajan, S. Veliciu, Adriana Zamfir
1University of Bucharest
2 Institute of Geology and Geophysics, Bucharest
A study of the oxidation tendency exhibited by sulfide ore bodies and of
the heat generated by the exothermic chemical reactions has been performed
taking into account geological, geochemical and thermodynamic factors which
influence these phenomena.
Geothermic measuring techniques applied to the Baia de Aries Mine outlined
the increase of temperature inside the oxidized metallic sulfide ore bodies
directing attention to the possible zones where endogenous fires might occur.
Key words: ore self-ignition, geothermic measurements, oxidation of sulfide
ore bodies.
MAGNETIC WITHIN AREAS COVERED BY SHALLOW DEPTH WATERS
IN NORTH DOBRUJA
L. Besutiu, Vl. Rosca, C. Maran
Institute of Geology and Geophysics, Bucharest
Magnetics within the Babadag Lake area, by a methodology worked out at the
Institute of Geology and Geophysics, has led to the elaboration, for the first
time in our country, of a high precision ( = ±1.3
nT) magnetic map offering a consistent image of the geomagnetic field on the
basis of land and
shallow waters observations.
The methodology and main results of the researches carried out within the Babadag
Lake area are presented.
Key words: magnetics, shallow depth waters, maps.
THE BLACK SEA. RADIOMETRIC INVESTIGATIONS 1988
M. Pauca2, Aluna Brana1, M. Barbu1, I. Fekete1, I. Manea1,
I. Isvoreanu1, V. Rosca1
1 Institute of Geology and Geophysics, Bucharest
2University of Bucharest
The paper presents the radiometric investigations which were made in 1988
on the continental platform of the Black Sea, south of Sulina. These investigations
were carried out by means of logging equipment on profiles oriented W–E
up to 5 km into the sea.
There were found anomaly zones which are equidistant and parallel to the beach
and are caused by accumulations of heavy minerals.
Key words: radiometric investigations, continental platform, Black Sea, anomaly
zones, accumulation of heavy metals.
MAGNETOTELLURIC STUDIES IN THE NEOGENE-VOLCANIC ZONE
(HARGHITA MOUNTAINS) FROM THE EASTERN CARPATHIANS
D. Stanica, Maria Stanica
Institute of Geology and Geophysics, Bucharest
Magnetotelluric researches carried out on four profiles in the Neogene-volcanic
zone have contributed to draw up some geoelectrical models of the crust and
upper mantle. In these models, the structural relations between the Neogene-volcanic
rocks and the sedimentary complex below them, between the sedimentary complex
and the high resistivity basement, as well as between lithosphere and asthenosphere,
as main resistivity contrast limits, are emphasized.
Key words: geoelectrical model, resistivity contrast, asthenosphere.
THE EVALUATION OF THE TOPOGRAPHIC CORRECTIONS FOR
THE RESISTIVITY METHOD BY PHYSICAL SCALE MODELING
I. Stoica, M. Josan
Enterprise of Geological and Geophysical Surveys, Bucharest
The paper presents the features of the apparent resistivity anomalies due
to several 2-relief forms of the valleys and ridges types for the most common
electrode arrays in a homogeneous and isotope medium. Graphs for evaluation
of relief corrections for the longitudinal gradient array and vertical electrical
sounding have been produced. The methodology for obtained the 3-D topographic
corrections is also presented together with an example of its application to
the field data interpretation.
Key words: resistivity, method, topographic, corrections, physical scale modeling.
EXPERIMENT REGARDING THE MULTISPECTRAL RECORDINGS
EXPLOITATION FOR COMPLETION OF THE SURVEYING DRAWINGS
NECESSARY FOR THE GEOLOGICAL AND GEOPHYSICAL RESEARCHES
M. Horomnea1, M. Popescu1, I. Balu2
1Enterprise of Geological and Geophysical Surveys, Bucharest
2Institute of Geology and Geophysics, Bucharest
There is presented the processing technology of the multispectral recordings
having in view the exploitation of the stereorecording apparatus, which includes:
–
primary recordings processing;
–
designing and execution of aerotriangulation;
–
preparation and execution of stereorestitution.
Finally, a comparative study is presented regarding the drawing up at 1:5000
scale using the usual aerophotography and multispectral recordings.
Key words: multispectral recordings, stereorecordding apparatus, aerotriangualtion.
POSSIBILITIES IN RADIOMETRY OF SOLVING THE DIRECT PROBLEM
S.R. Constantinescu
Enterprise of Rare Metals, Bucharest
The paper presents two methods of solving the direct problem. The former
relies on determining the solution of the radiations transport equation by
Legendre polynomial approximation; the latter uses the statistical procedures
for stimulating the gamma rays transport.
Possible applications, the use of the results in the interpretation of the
radiometric data are given.
Key words: algorithm, solving of the direct problem in radiometry.
THE USE OF RADIOMETRIC METHODS IN GEOLOGICAL MAPPING
Radu Erhan, Ludovic Matyas, Nicolae Maiorescu
Enterprise of Rare Metals, Bucharest
In certain geological conditions, the mineralogical composition of the rocks
leads to the formation of significant radioactive contrast. By using an adequate
equipment, with an appropriate method of measuring and control, it is possible
to get maps of the radioactivity fields, by means of which one could delimit
the geological formations. The trench control enables the extrapolation, on
large areas and with a good precision, of these limits and a high economic
efficiency resulting from the diminished mining expenses.
Key words: radioactive contrast, geological mapping, extrapolation.
CONTRIBUTIONS TO THE INTERPRETATIONS METHODOLOGY
OF THE NATURAL GAMMA LOGGING DATA
R. S. Constantinescu, Verona Ursu
Enterprise of Rare Metals, Bucharest
Processing data methods for natural gamma logging are presented by deconvolution
with an inverse filter and a Wiener one. The calculation programs as well as
the comparative results for applying the two methods on different grades and
geometry strata are given.
Key words: data processing, natural gamma logging.
AUTOMATIC PROCESSING OF THE RADIOMETRIC DATA
Ghe. Grecea
Enterprise of Rare Metals, Bucharest
By means of automatic processing of radiometric data (and their corroboration
with other geophysical, geochemical and geological data) the errors level is
diminished, the relationship with the geological support is established (the
discrimination and classification analysis) and the interest areas are delimited
(statistical analysis, factorial analysis).
Key words: processing, error, interest area.
GAMMA-RAY SPECTROMETRY SAMPLING ON SEVERAL URANIUM
MINERALIZATIONS
M. Sasarman
Enterprise of Rare Metals, Bucharest
The gamma ray radiometric sampling of the U mineralizations is faced with
serious difficulties due to the high weight of the multiple scattered radiations,
widely spread "in situ". The gamma ray spectrometry sampling presents
several advantages from this point of view, thus making possible the determination
of the mineralization nature.
The paper puts forth many theoretical considerations as well as the results
of some experimental works carried out in the field.
Key words: widely spread rays, signal/noise ratio, "in situ" gamma
ray spectrometry, U/Th ratio, specific activity.
AUTOMATIC PROCESSING OF ALPHA SPECTROMETRIC SPECTRA
OF RADIOACTIVE ORES
D. Zazuleac
Enterprise of Rare Metals, Bucharest
Over the last years, important progress has been made in processing the complex
spectra of the loaded particles collected from different sources.
The paper presents an automatic processing mode of alpha spectrometric complex
spectra on "thick sources" from the geological medium, through their
deconvolution in monoenergetical spectra.
Key words: alpha-spectrometry, thick sources, deconvolution
IIIrd SECTION: EARTH'S PHYSICS
Council Board: Prof. Liviu Constantinescu, corresponding member of the Romanian
Academy, Dr. Crisan Demetrescu, leutenant General (r) ing. Vasile Dragomir,
Dr. Ioan Draghici, Dr. Cornelius Radu, Dr.ing. Dorel Zugravescu
THE STUDY OF THE LARGE QUARRY BLASTS PERFORMED
IN ROMANIA IN THE PERIOD 1971 – 1985
V. Smalbergher, Fl. Radulescu, M. Anghel
Institute for Earth's Physics, Bucharest
1014 large quarry blasts carried out on the Romanian territory in the period
1971 – 1985 recorded by the national seismological network were analysed
in the paper. Using the arrival times of the Pg, Sg, Pn and Sn waves the quantitative
distributions of seismic velocities in the Earth's crust and upper mantle of
the Southern Carpathians, Eastern Carpathians, Apuseni mountains and Transylvanian
Depression was obtained.
Key words: seismic waves, velocity distribution, Earth's crust, upper mantle.
ON THE GEOTHERMAL REGIME OF THE MOESIAN PLATFORM
AND GETIC DEPRESSION
Maria Andreescu, D. Burst, C. Demetrescu, M. Ene,
O. Haradja, Gabriela Polonic
Institute for Earth's Physics, Bucharest
75 geothermal gradient measurements in thermally stabilized boreholes, rather
uniformly distributed over the study area, enabled a heat flow map to be produced
and relationship tectonics-heat flow to be discussed. Simple conductive models,
revealing interesting features of the thermal structure of the crust, are presented.
Key words: heat flow, crust, thermal structure, Moesian Platform, Getic Depression.
DATA CONCERNING THE ASSESSMENT OF THE GEOLOGICAL
RISK IN ROMANIA
N. Mandrescu
Institute for Earth's Physics, Bucharest
In this paper some results of the researches performed in two main directions:
(1) the geological hazard assessment in the extra-Carpathians territory (intermediate-depth
earthquakes and the present-day geodinamical processes) and (2) the estimation
of the degree of the population exposure to this hazard are presented.
Key words: intermediate-depth, earthquake, present-day geodynamical processes,
population-at-risk, liquefaction, landslide, geological hazard.
PECULIARITIES OF THE CORRELATION BETWEEN GRAVITY
TIDES AND EARTHQUAKES
Dorel Zugravescu, Ileana Fatulescu, D. Enescu, Doina Danchiv, O. Haradja
Institute for Earth's Physics, Bucharest
The paper presents the results concerning the correlation between the moments
of earthquakes occurrence (earthquakes occuring in two zones comprised between
the 25.7° and 28.2° meridians) and the gravity tide variations as they
were recorded at the Caldarusani Geodynamic Observatory (the 26.2° meridian),
in the interval April 1977 – August 1987. The first seismic zone is the
Vrancea earthquakes one (comprised between latitudes 45.3° and 45.9° north)
and the second seismic zone is a zone situated south-east of the Crete Island
(comprised between latitudes 33.6° and 35.6° north).
The triggering role of the maximum/minimum of the gravity tide, as well as
of the movements of maximum rapidity in the gravity variation was made obvious.
In the case of Vrancea earthquakes, where their occurrence mechanism is known,
the triggering role of the maximum for the shocks occuring in the fault fields
parallel to the Carpathian Bend, respectively the triggering role of the minimum
for the shocks occuring in the fault fields perpendicular to the Carpathian
Bend was made obvious.
Key words: geodynamic, Earth tide, earthquakes, triggering effect, Vrancea
region, East Crete region.
CONTRIBUTIONS TO THE STUDY OF SPACE AND TIME DISTRIBUTION
OF THE VRANCEA REGION SEISMIC ACTIVITY
Luminita Ardeleanu
Institute for Earth's Physics, Bucharest
The aim of this work is to develop previous researches (Radu, Ardeleanu,
1988) by studying the depth dependence of the space and time distribution of
the earthquake which occurred in the Vrancea intermediate depth focal region
(h > 60 km) in the period June 1977 – May 1988. A special attention
is given to detection of possible depth-dependent changes in the seismicity
patterns
preceding major earthquakes.
Key words: Vrancea region, intermediate depth earthquakes, seismicity patterns.
DETAILED CONFIGURATION OF VRANCEA INTERMEDIATE DEPTH
SEISMICITY
C. I. Trifu
Institute for Earth's Physics, Bucharest
About 200 earthquakes with h > 60 km and ML > 3.3 occurred between
1981 and 1986, previous to the major earthquakes of August 30, located by the
JHD method,
allowed to emphasize the asperity which generated this event (r = 7.5 km).
Taking also into account the one year activity following it, the existence
of two active zones is emphasized too, between 80 – 100 km and 120 – 170
km depth. They can generate maximum Mw magnitudes of about 7.2 – 7.5
and 7.3 – 7.8, respectively.
Key words: active zone, asperity, maximum magnitude.
ANALYSIS OF VRANCEA INTERMEDIATE DEPTH MICROSEISMIC ACTIVITY
C. I. Trifu, M. Radulian, E. Popescu
Institute for Earth's Physics, Bucharest
Based on the difference of the P and S wave arrival times at MLR and VRI
seismic stations, about 2000 earthquakes of magnitude MD > 2.0 have
been located on depth, using the h = f(tS-P) relationship established for about
300 locations
by the JHD method. The depth and magnitude distributions are analysed. The
characteristics of microseismic activity are emphasized, together with the
correlation with major earthquakes occurrence.
Key words: Vrancea region, microearthquakes, frequency magnitude relation.
A SEISMIC CYCLE MODEL BASED ON THE PRECOLATION PHENOMENON
C. I. Trifu, M. Radulian
Institute for Earth's Physics, Bucharest
A model of the seismic cycle is introduced starting from the existence of
a distribution of stress inhomogeneities (asperities) along the seismic active
zone and the tectonic stress precolation on it. The model is applied to the
Vrancea intermediate depth region. It offers a physical basis for the understanding
of the earthquake generation process and enables the estimation of several
quantities of interest in long-term prediction (maximum magnitude, recurrence
period).
Key words: seismic source, precolation, major earthquake.
EARTHQUAKE HAZARD PARAMETERS FOR VRANCEA
(ROMANIA) SEISMOGENIC REGION
V. I. Marza1, A. Kijko2
1Institute for Earth's Physics, Bucharest
2Institute of Geophysics, Warsaw, Poland
Using an extension of the maximum likelihood procedure, the Vrancea-induced
earthquake hazard parameters
(1) maximum magnitude, MGrmax = 7.8 (±0.2),
(2) Gutenberg-Richter distribution slope, b = 0.64 (±0.01), and
(3) average activity rate (for MGrmin = 2.2), 
=
85.32 (±3.25),
were estimated, by synergically merging: (i) mixed data (i.e., both extreme
and complete parts of the Vrancea earthquake file over 1984 – 1986),
(ii) consideration of appropriate time-varying completeness thresholds, and
(iii) incorporation of magnitude uncertainties.
Key words: seismic hazard, maximum magnitude, b-value, Vrancea (Romania).
THE TULCEA EARTHQUAKE OF NOVEMBER 13, 1981
M.C. Oncescu, Olivia Bazacliu, Emilia Popescu
Institute for Earth's Physics, Bucharest
The crustal earthquake from Tulcea (ML = 5.4) and 6 of its strongest aftershocks
were relocated together using the JHD technique. The fault plane solution was
redetermined using exact ray tracing in a layered structure. One of the nodal
planes coincides with the NE – SW alignment of epicenters suggesting
a similar orientation of the rupture plane.
Key words: Tulcea, seismic sequence, rupture plane.
ON THE MAGNETIC AN ELECTRIC STRUCTURE OF THE LITHOSPHERE
IN EUROPE
C. Demetrescu1, Maria Andreescu1, T. Nestianu2
1Institute for Earth's Physics, Bucharest
2Institute of Geology and Geophysics,
Bucharest
The lateral variation of magnetic and electric properties of the lithosphere
in Europe is derived, based on the magnetic and electromagntic induction by
the solar-cycle-related component of the external dipole. As input data annual
means of the horizontal and vertical components of the geomagnetic field at
European observatories and available spherical harmonic coefficients of the
external dipole were used.
Key words: Europe, lithosphere, magnetic induction, solar cycle, external dipole,
magnetic properties.
PALEOMAGNETISM OF THE LARAMIAN MAGMATISM IN THE
APUSENI MOUNTAINS AND ITS TECTONIC IMPLICATIONS
S. Patrascu1, M. Bleahu2,
C. Panaiotu3
1University of Bucharest, Faculty of Physics
2Institute of Geology and Geophysics, Bucharest
3Institute for Earth's Physics, Bucharest
Paleomagnetism of the Laramian magmatism in the Apuseni Mountains was studied
in 47 collecting sites (173 samples, 692 specimens). After AF cleaning, characteristic
magnetization were identified for various collecting areas in the studied zones,
thus delimiting a few spatial and temporal units for which paleomagnetic poles
could be statistically derived. Based on paleomagnetic results we discuss the
tectonic implications.
Key words: Apuseni Mountains, Laramian magmatism, paleomagnetism, tectonic
implications.
NEW GEODETIC CONTRIBUTIONS IN GEODYNAMIC STUDIES
D. Ghitau
Institute of Civil Engineering, Bucharest
Recent contributions in the field of geodetic metrology – particularly
as far as accuracy is concerned – open promising prospects for interdisciplinary
investigations. Such prospects are reported for geodynamics with emphasis on
the local example of the Caldarusani-Gruiu poligon.
Key words: Geodynamics, spatial geodesy, spatial coordinates.
ACHIEVEMENTS AND PERSPECTIVES IN THE FIELD OF A LAND
INFORMATION SYSTEM (LIS) IMPLEMENTATION TO MONITOR
THE EARTH AT REGIONAL LEVEL
N. Oprescu1, I. Ionescu1,
I. Noaje2
1Institute of Civil Engineering, Bucharest
2Centre of Astronomy and Space Sciences, Bucharest
The quantitative and qualitative development of the information flow acquired
using aero-satellite remote sensing system is presented. The complexity of
modern life imposes: (1) to approach and handle these data flow in an informatics
manner; 2) to fulfil the tasks referring to inventory, monitoring and forecasting
modeling, according to the specific objects and phenomena (slow, medium or
rapid variable in time; regenerable and nonregenerable), with implication in
practically all fields of the national economy, at local, territorial and regional
level.
LIS characteristics relative to data banks on poly- and interdisciplinary activities
are presented, along a case study for the Danube Delta and the Black Sea coast
area.
Key words: Land Information System (LIS), remote sensing, monitoring, polydisciplinarity.
SURVEYING PROCESSING PROCEDURE PERFORMED ON GEODETIC
GRAVIMETRIC MICRONETWORKS
D. Ghitau, I. Somirdolea, C. Marcu, C. Moldoveanu
Institute of Civil Engineering, Bucharest
Modern observations and processing procedure performed on geodetic-gravimetric
micronetworks are presented: the detection of outliers, the determination of
some instrumental parameters, etc., with particular reference to the Gruiu-Caldarusani
geodetic-gravimetric network of the Geodynamic Polygon.
Key words: Geodetic-gravimetry, observations processing.
SIMULTANEOUS DETERMINATION OF THE LATITUDE, LONGITUDE
AND ASTRONOMICAL AZIMUTH ON THE BASIS OF A RIGOROUS
WEIGHTING SYSTEM
M. Atudorei
Institute of Civil Engineering, Bucharest
A rigorous method aiming at simultaneous determination of latitude, longitude
and astronomical azimuth of the terrestrial direction from azimuthal observations
is presented, introducing a proper weighting system for angular and time measurements.
Key words: geodetic astronomy, position astronomy.
THE GENERAL MATHEMATICAL SOLUTION OF THE PROBLEM
OF THE RECTILINEAR DISTANCE DETERMINATION FROM
THE OPTIC LENGTH
M. Atudorei, A. Ilies
Institute of Civil Engineering, Bucharest
Differential Equations of the trajectory in the three dimensional space are
inferred according to Fermat's minimum time principle, in the hypothesis when
scalar field at atmospheric refraction is known.
Then the rectilinear distance involved in subsequent geodetical computations
is determined.
Key words: geodetic measurements by waves, electronic apparatus for distance
determination, space coordinates system.
STATISTICAL TESTS FOR PROCESSING OF REPEATED GEODETIC OBSERVATIONS
C. Savulescu
Institute of Civil Engineering, Bucharest
Statistical tests for processing of repeated geodetic observations are presented
in different computation stages with a view to appreciating the measurement
quality, improving the functional-stochastic model and estimating the accuracy
of the final result.
Key words: statistical tests, repeated geodetic observation.
THE SEPARATION AND SIGNIFICANCE OF A REGIONAL GRAVITY
ANOMALY IN THE CIUC DEPRESSION
A. Proca, V. Nicolau
Enterprise of Geological and Geophysical Surveys, Bucharest
The attempts at the quantitative interpretation of the gravity anomalies
from the Ciuc Depression and its surroundings have shown that they contain
a strong regional influence, caused by a step at the Mohorovicic surface level.
This interpretation has been recently substantiated by the results obtained
by other geophysical investigations.
Key words: regional gravity anomalies, the Ciuc Depression.
PROJECT OF THE ESSENTIAL GEODETIC NETWORK IN THE
SOCIALIST REPUBLIC OF ROMANIA USING THE TRILATERATION METHOD
M. Horomnea, C. Paunescu
Enterprise of Geological and Geophysical Surveys
We propose a project of trilateration with a reduced number of points, respectively
128 (46) points whose lengths will be measured by a performance instrument
(Wild DI 150 or another).
The proposed geodetic network is to be performed in 2 field campaigns by surveyors,
endowed with a helicopter, 2 land-cars and aninterchangeable instrument (transmitter-reflector).
Measuring the atmospheric parameters during the sighting, a high accuracy can
be obtained, superior to the existing triangulation network of the I-st order.
Key words: geodetic network, trilateration method.
THE INFLUENCE OF THE HORIZONTAL MOVEMENTS ON THE
SUBSIDENCE OF THE TRANSYLVANIAN BASIN
C. Cranganu
"
Al. I. Cuza" University of Iasi, Faculty of Biology-Geography-Geology,
Iasi
During the formation of the Transylvanian Basin the prevailing vertical movement
(subsidence) was combined with horizontal movements due to the relative shifting
of the segments of plate or microplates that are present and active within
the Romanian territory. These horizontal movements acted as a vice on the Transylvanian
Basin, being involved in eustatic movements, sedimentation velocities, migration
of the subsidence axes, etc.
Key words: subsidence, Transylvanian Basin, horizontal movements, tectonic
plate (microplates).
CONSIDERATIONS ON THE VERTICAL REFRACTION COEFFICIENT
MAGNITUDE IN GEODESIC TRIGONOMETRICAL LEVELLING
C. Borduselu, M. Popa
Institute for Studies and Designs for Land Improvement, Bucharest
This paper deals with a statistical analysis of the correction to be made
on geodesical trigonometrical levellings due to vertical refraction; it is
based on the interpretation of the results of about 500 determinations of bilateral
trigonometrical levellings; these determinations (data) have been obtained
from geodetical levelling traversing, based at both ends on levels from geometrical
levellings.
The value of level differences shows a systematic error assigned to the vertical
refraction influence.
This conclusion has been confirmed by the measurements carried out in an experimental
polygon with sizes between 500 and 2000 m, where the level differences were
measured both by trigonometrical levelling and by geometrical levelling.
Key words: trigonometrical levelling, vertical refraction coefficient.
TENDENCIES OF THE EVOLUTION OF THE BLACK SEA MEAN LEVEL
C. Bondar
Institute of Meteorology and Hydrology, Bucharest
The processing and analysis, from the hydrological standpoint, of the data
on level measurements, performed over a long time interval in various points
situated in the Black Sea reveal that the water level in the basin of the Black
Sea shows a continuous rising tendency. The characteristic according to which
the permanent rising tendency of the Black Sea does not depend upon the Black
Sea water balance is pointed out.
Key words: hydrological analysis, Black Sea, hydrological levels, tendencies,
water balance.
PRELIMINARY REMARKS ON THE VARIATION TENDENCY
OF THE TOTAL OZONE AMOUNT IN BUCHAREST
M. Frimescu, Laura Manea
Institute of Meteorology and Hydrology, Bucharest
On the basis of data on the total ozone amount in Bucharest in the time interval
1980 – 1988 the authors make in their object to study the variation tendency
of the total ozone amount. The seasonal and annual variations occuring in the
respective interval are pointed out. Several remarks are made on the negative
ozone fluctuations on the winter 1982 – 1983, as well as on those of
1985 and 1988, related to the eruption of the El Chichon Volcano (1982), the
variations of the El Nino and the quasibiennial fluctuations of the wind distribution
in the tropics.
Key words: total ozone, tendencies, variations, seasonal fluctuations, biennial
fluctuations.
OCCURRENCE OF RARE METEOROLOGICAL EVENTS IN
SOUTH-EASTERN EUROPE AGAINST THE PRESENT
CLIMATIC BACKGROUND
C. Mares
Institute of Meteorology and Hydrology, Bucharest
The rare thermal precipitation events in Romania are analysed on the basis
of daily measurements at stations with long data series available (1885 – 1985),
and sequences of dry and rainy intervals are determined.
Adequate distribution functions are determined and an attempt is made at the
forecast of rare events in connection with large scale uncommon situations.
A procedure consisting in a qualitative filling in of the discontinuous data
series is tested, on the basis of data series from stations with continuous
data series available.
Key words: thermal regime, precipitation regime, dry intervals, distribution
function, forecast permanency.
THE "GEO" INFORMATION SYSTEMS
N. Zegheru, N. Jalba
Institute of Geodesy, Photogrammetry, Cartography and Territory Organisation,
Bucharest
Continuous promoting LIS/GIS developments, at the same time emphasizing their
common technological characteristics and differences are briefly presented
in this paper. In fact, the tendency to carry out a complex and automatic cadastre
entails a land information system development. The Romanian land information
system development stage, as well as some of its important applications, computer-assisted
designing, are given.
Key words: informational system, geodetic SIG, land information system, SIG
internal structure.
THE GENERAL LAND CADASTRE – AN IMPORTANT LINK IN THE
LARGE FAMILY OF INFORMATION SYSTEMS
N. Jalba1, L. Jalba2
1Institute of Geodesy, Photogrammetry,
Cartography and Territory Organisation, Bucharest
2Electronica, Bucharest
Some elements of a new concept on the general land cadastre aiming at an
expert system development are given in this paper.
This system will facilitate both the processing of information by stages, from
particular to general and from general to particular, and the transformation
of the general land cadastre into an information interdisciplinary process.
Key words: land cadastre, information processing.
PROCESSING BY FAST ALGORITHMS OF SATELLITE IMAGES FOR
GEODETIC AND GEOPHYSICAL PURPOSES
L. Jalba
Electronica, Bucharest
On an image there is a lot of information we cannot grasp by simply viewing
it, at the same time a lot of information does not matter for us (redundance).
Image processing is the was to deal with these two problems. A Fast Fourier
Transform processor – in TTL technology – microprogrammed and interfaced
with a pattern memory is part of our image processing system.
Investigating the pattern signal Fourier spectrum we try to reduce the noise
by means of a correlation function.
Key words: Fourier transform processor, fast algorithms, correlation function.
CHOOSING THE PIXEL DIMENSION ON A SATELLITE IMAGE
IN ACCORDANCE WITH THAT OF A VIDEO IMAGE DIGITIZED
TO ASSURE THE QUALITY OF VISUAL OBSERVATION
L. Jalba
Electronica, Bucharest
The quality of a visual message in the processing image philosophy is a question
of sampling too.
Choosing the sampling frequency in accordance with the scale of the received
images together with the image memory allocation for an interactive system
is the purpose of this paper.
Electronic zoom and intelligently stored information, parts of the processing
image facilities, are useful for geodesy or geophysical applications.
Key words: satellite image, sampling frequency, image facilities.
GEODESY ANG GEOPHYSICS – THEIR PARTICIPATION
IN THE COMMON EFFORT FOR KNOWLEDGE
I. Ghica1, Ileana Fatulescu2
1Military Topographic Direction, Bucharest
2Institute for Earth's Physics, Department of Geodynamics, Bucharest
The paper points out the contribution of geodesy and astronomy to the research
of the cosmic space and the Earth, as well as the strong impact of these two
fields of science on geophysics with a view to studying the periodic and nonperiodic
deformations of the Earth.
Key words: Geodesy, astronomy, geodynamics, geodynamic observatories.
AUTOMATIC COMPILATION OF THE GRAVIMETRIC MAP WITH
BOUGUER ANOMALIES IN THE INTERNATIONAL SYSTEM 1980
N. Gulie1, D. Bacanu1,
Felicia Alexandru1, A. Nicolaescu2
1Military Topographic Direction, Bucharest
2Institute of Geology and Geophysics, Bucharest
A variant of a gravimetric data base is presented together with a methodology
to obtain the Bouguer gravimetric anomalies as application.
For the automatic plotting of isolines, a program for the P.C. – "JUNIOR" was
formulated and implemented.
Key words: gravimetry, Bouguer anomaly, data base, isoline, automatic
plotting.
NEW POSTULATES OF MOTION, THE UNITARY CAUSAL DECIPHERING
OF THE NUCLEAR FORCES OF GRAFITY AND UNIVERSAL ATTRACTION
V. Caramalau
P.O.Box, Bacau
Concepts:
– Philosophical ones – the exclusion of universal becoming, the exclusion
of the existence of a universal physical time – the indestructible connection
between matter and motion (the things' essence is immuable from the physical
and dynamical point of view),
– Experimental ones – the law of energy conservation, the quantization
of energy and of mechanical systems, the organization of matter involving undulatory
phenomena.
Postulate: the Universe consists of elementary, fundamental, indestructible
and equal (from the physical and dynamical point of view) particles, able to
move inertially or linearly with a constant velocity (c) or specific undulatorily,
leading to stable physical-dynamic structures.
Key words: gravity, universal attraction, undulatory phenomena.
THE EXPRESSION OF THE PRESSURE GRAVITATIONAL FIELD
IN THE MODEL "IMPULSE", NIM, PROPOSED BY NEWTON
"
IN HIS OPTICS"
I. Adamut
Romanian National Committee of Astronomy, Bucharest
Newton's Impulse Model of gravitation, NIM, has two constituent, both of
them composed by only inert, but not heavy, matter: 1) An "Any Medium
Whatever", AMW, a dynamical isotropic homogeneous, continuous medium, "probably… formed
by matter in solid, massy, hard, impenetrable, movable particles"; 2) "porous
bodies compound of them" (particle, n.n.), O1. The flux intensity of AMW
is attenuated by passing through the matter of a body O1, according to Bouguer-Lambert's
law, due to absorption of its kinetical energy, thus breaking its central symmetry.
As a consequence there results a gravitational pressure field p(r), and a gravitational
attraction one, , directed to the centre of body, too. Its expression contains
a main term identic with , and complementary terms of higher order, whose necessity
was supposed by Poincaré. Its value is less that one of – field
from Newton's Attraction Model, NAM, in accordance with the experience. For
the Earth being the radius of the Earth.
Key words: Attenuation, absorption, continuous medium, kinetical energy inertia,
gravitation central symmetry, Newton's Impulse Model.
NORMAL GRAVITY FIELD IN THE ROMANIAN TERRITORY
M. Visarion
Institute of Geology and Geophysics, Bucharest
The reduction of a normal field is at present differently calculated, either
by the Helmert formula (1901) which applies gravity data to physical geodesy,
or by the Cassinis formula (1930) for drawing up the gravimetric maps on different
scales. The present paper proposes a unitary reduction system based on the
international formula adopted at the 17th IUGG General Meeting (GRS-1980).
Therefore, the normal field values have been calculated between the 43°30',
and 48°30' latitudes, which delimit the territory of Romania, at 10" intervals.
Rapid ways for transferring the available values to the new system are presented.
Key words: Geodetic Reference System, geocentric gravitational constant
angular velocity, dynamical form factor, flattening, linear excentricity.
ON THE NORMAL GEOMAGNETIC FIELD (NGF) MODELING
BY THE HELP OF THE POWER SERIES
L. Besutiu, G. Ionescu
Institute of Geology and Geophysics, Bucharest
The paper deals with the problem of the NGF modeling, especially within limited
areas. Basic approaches to its implementation are briefly reviewed underlining
the physical support of the mathematical models used. NGF models for the Romanian
territory by Taylor series and harmonic analysis are produced and limits of
the power series representations used so far along with their physical meaning
discussed.
Key words: geomagnetism, normal field, harmonic analysis, Taylor series errors,
Romania.
SPECTRAL ANALYSIS OF GEOMAGNETIC VARIATIONS RECORDED
AT THE SURLARI GEOPHYSICAL OBSERVATORY
A. Soare, V. Steflea, Alexandra Ionescu
Institute of Geology and Geophysics, Bucharest
The periods and amplitudes of the principal types of variation were obtained,
based on a spectral analysis performed on long series of geomagnetic variation
data recorded at the Surlari Geophysical Observatory.
The complex demodulation was employed in the study of temporal variations of
amplitudes for some of the prominent phenomena.
Key words: spectral analysis, geomagnetic variations, complex demodulation,
Surlari Geophysical Observatory.
INFORMATION ABOUT DEEP STRUCTURES ON A PROFILE ACROSS
THE EASTERN CARPATHIANS USING GEOMAGNETIC WELLING
A. Soare, Gabriela Cucu, Mioara Alexandrescu
Institute of Geology and Geophysics, Bucharest
Recordings of last geomagnetic variations were realized in 12 stations from
the Pascani – Targu Neamt – Ditrau – Reghin profile. The
levels of conductivity differences from the underground, using the deep geomagnetic
welling and the curves correlation from the spectral analysis were given. The
principal electric conductivity domains and structural accidents were rendered
evident.
Key words: geomagnetic welling, conductivity differences, East Carpathians.
HEAT FLOW IN THE WESTERN BLACK SEA
S. Veliciu, O. Dicea, L. Morosanu
Institute of Geology and Geophysics, Bucharest
This work presents a preliminary map of the earth's caloric flux distribution
in the west part of the Black Sea.
Regional tectonics characteristics were discussed in correlation with geothermal
data.
Key words: geothermal flux, Black Sea, regional tectonics.
LATERAL VARIATION AND FREQUENCY DEPENDENCE OF THE
Q FACTOR FOR ROMANIA
Victoria Oancea1, Olivia Bazacliu1, G. Arsene2,
Georgeta Mihalache2, Al. Dumitrascu2
1Institute for Earth's Physics, Bucharest
2INCREST – Department of Mathematics, Bucharest
The values of the Q factor are determined from the coda envelope shape and
from the dependence of the predominant frequency of the coda on time. Sets
of earthquakes which occurred in different seismic zones in Romania are analysed
and the lateral variation of the Q values is evidenced. The frequency dependence
of the Q factor is determined.
Key words: Q factor coda envelope shape, predominant frequency.
QUARTZ STRAINMETER UNDER ROUTINE OBSERVATION WITHIN
THE GEODYNAMIC LABORATOARIES
Dorel Zugravescu1, O. Haradja1, S. Filimon1, Ileana Fatulescu1,
H. Aoki2, Y. Sumino2, T. Ooida2
1Institute for Earth's Physics, Department of Geodynamics, Bucharest
2Reserch Center for Seismology and Volcanology, School of Science, Nagoya University,
Nagoya, Japan
The strainmeter, now under routine observation within the laboratory of Calibration
and Ageing of the Geodynamical Apparatus – Bucharest, respectively with
the Draica Geodynamic Underground Obsrevatory belonging to the Craciunesti – Deva
Geodynamic Underground Polygon, was realized in cooperation with Japanese researchers.
It is designed to point out:
– periodical deformations of the Earth due to the Earth's tides;
– nonperiodical deformations of the tectonic compartments due to the earth
crust dynamics.
Both types of strainmeters will be installed within the geodynamic underground
observatories and the less sensitive type (the second one) will be installed
in the geodynamic polygons arranged in zones which are of special interest
from the geodynamical point of view.
Key words: geodynamic, crust deformations, quartz strainmeter, magnetic displacement
transducer, Earth tide, underground observatory.
WATER-TUBE TILTMETER UNDER ROUTINE OBSERVATION
WITH THE GEODYNAMIC LABORATORIES
Dorel Zugravescu1, O. Haradja1,
S. Filimon1, Ileana Fatulescu1,
H. Aoki2, Y. Sumino2,
T. Ooida2
1Institute for Earth's Physics, Department of Geodynamics, Bucharest
2Reserch Center for Seismology and Volcanology, School of Science, Nagoya University,
Nagoya, Japan
The tiltmeter, now under routine observation within the Laboratory of Calibration
and Ageing of the Geodynamical Apparatus – Bucharest, was realised in
coperation with Japanese researches. It is designed for a reliable continuous
recording of periodical tilts of the Earth due to the earth tides, in the frame
of the geodynamical observatories, respectively, nonperiodical tilts of the
tectonic compartments due to the earth crust dynamics in the frame of the geodynamical
polygons.
The water tube tiltmeter consists of two communicating vessels, their displacement
on the vertical, a result of the tilting of the crust, is made conspicuous
by two differential vertical displacement transducers.
Key words: geodynamic, crust deformation, water-tube tiltmeter, magnetic displacement
transducer, earth tides, underground observatory.
SIZE HIERARCHIZATION OF THE BLOCKS CONSTITUTING THE
EARTH CRUST – EXPERIMENTAL FACTS AND MATHEMATICAL MODELING
F. Munteanu1, Dorel Zugravescu2, M. Rusu3, Ileana Fatulescu2
1The Polytechnic Institute of Bucharest – M. C. T. Faculty
2Institute for Earth's Physics, Department of Geodynamics, Bucharest
3University of Bucharest – Faculty of Physics
Sadovskii proved experimentally that materials have preferential sizes, the
distribution of these preferential sizes, between 10
and 10
m
presenting a hierarchy. As a first step to a unitary theory a mathematical
modeling – in
good agreement with experimental data – is proposed.
Key words: hierarchization, homothetical, division into fragments, tectonic
blocks, mathematical modeling.
A GEODYNAMIC EXAMINATION OF THE TERRITORY OF S.R. OF ROMANIA
BY THE REPEATED HIGH ACCURACY LEVELMENT
V. Dragomir1, Dorel Zugravescu2,
N. Jalba3, Ileana Fatulescu2
1Romanian National Committee of Geodesy and Geophysics, Bucharest
2Institute for Earth's Physics, Department of Geodynamics, Bucharest
3Institute of Photogrammetry, Geodesy, Cartography and Territory Organization,
Bucharest
Starting from the anomaly which the Vrancea earthquake of August 30, 1986,
has produced in the distribution of the gravity field on the Caldarusani-Gruiu
and Nehoiu-Bisca Rozilei Geodynami Polygons, anomaly which was explained as
a vertical displacement of the adjacent tectonic compartments constituting
these polygons, the authors looked for the materialization of these displacements
in the Ist order levelment of Romania.
Some zones were the rate of the vertical relative displacement of the adjacent
tectonic compartments reaches 7 cm/year were put into evidence.
The paper presents only the step-type levelment anomalies which are causally
connected to the seismotectonics of the S.R. of Romania.
Key words: S.R. of Romania territory, geodynamic, geodetic network, high accuracy
levelment, seismo-tectonics.
ESTIMATIONS OF SOME PARAMETERS OF THE SUBDUCTION
PROCESS IN THE NOWADAYS EAST CARPATHIANS AND
THE TYPE OF THIS SUBDUCTION ZONE
D. Enescu, Dorel Zugravescu, Ileana Fatulescu
Institute for Earth's Physics, Department of Geodynamics, Bucharest
The age of the subducting (moving down) lithosphere fragment in Vrancea area
and the subducting (downwards) velocity of this fragment are estimated.
These estimations were based upon: 1) Ruff and Kanamori's empirical relation
between the maximum magnitude of the earthquakes occurring in several worldwide
subduction areas, on the one hand and the two parameters of the subduction
process, on the other hand; 2) geotectonical considerations concerning the
Alpine evolution of the Carpathians.
A comparison between the obtained values and those from the most worldwide
subduction areas leads to the hypothesis that the nowadays East Carpathians
subduction zone belongs to the insular arc-type zones.
Key words: subduction, insular arc-type zone, lithosphere age, subducting velocity
(convergent rate).
ESTIMATION OF PREMONITORY CRUSTAL DEFORMATIONS
OCCURING IN THE PREPARATION STAGE OF THE VRANCEA EARTHQUAKES
D. Enescu, A. Bala
Institute for Earth's Physics, Bucharest
For a "soft" inclusion in elastical semi-space, an analytical solution
proposed by Dobrovolski et al. was used. This solution consists of the expressions
of the Earth's surface deformation components induced by the "soft" inclusion
during the preparation stage of the earthquakes.
The Earth's surface deformations occuring in the preparation stage of the intermediate
high magnitude Vrancea earthquakes (M > 6.5) have been computed and the
maps with the distribution of the premonitory deformation values have been
drawn up. Based on these maps, correlations with the spatial distribution of
some other type phenomena, observed in the case of the Vrancea strong earthquakes
and "a posteriori" considered as being premonitory phenomena, have
been performed.
Key words: soft inclusion, premonitory crustal deformations, premonitory
phenomena.
THE GEODYNAMIC COMPLEX EXPERIMENTAL STATION WHICH
WILL BE SET UP IN THE FRAMEWORK OF THE CALDARUSANI-GRUIU
GEODYNAMIC POLYGON (GCES)
Dorel Zugravescu, O. Haradja
Institute for Earth's Physics, Department of Geodynamics, Bucharest
The GCES was designed in such a way as to shelter sensors requiring good
thermoisolation in as minimum as possible room.
After testing, the GCES of this kind will equip geodynamic polygons assuring
information collecting concerning the time evaluation of preseismic, coseismic
and postseismic phenomena taking place along an active seismic fault.
Key words: geodynamic, crust deformation, complex experimental station, earthquakes
prediction.
THE IV-th EXHIBITION OF APPARATUS FOR EARTH'S PHYSICS
AND APPLIED GEOPHYSICS
QUARTZ STRAINMETER EQUIPPED WITH MAGNETIC
DISPLACEMENT TRANSDUCER
Dorel Zugravescu1, O. Haradja1, S. Filimon1, Ileana Fatulescu1,
H. Aoki2, Y. Sumino2,
T. Ooida2
1Institute for Earth's Physics, Department of Geodynamics, Bucharest
2Reserch Center for Seismology and Volcanology, School of Science, Nagoya University,
Nagoya, Japan
It is deviced to work in two sensitivity fields.The first type, used for
making evident the Earth's periodical deformations, has errors exceeding no
more than ±10
m in the relative deformations. The second one, used for making evident the
Earth's nonperiodical deformations, has errors between
10
and 10
m
in the relative adjustable displacements, depending on the amplitude of the
relative displacements between tectonic compartments.
It is completely realized with Romanian components, excepting the Japanese
magnetic displacement transducer (Sony type). It presents particular reliability,
being able to work continuously for almost one year in 100% humidity conditions
in underground geodynamic observatories.
Key words: geodynamic, crust deformation, quartz strainmeter, magnetic displacement
transducer, earth tide, underground observatory.
WATER-TUBE TILTMETER EQUIPPED WITH MAGNETIC
DISPLACEMENT TRANSDUCER
Dorel Zugravescu1, O. Haradja1,
S. Filimon1, Ileana Fatulescu1,
H. Aoki2, Y. Sumino2,
T. Ooida2
1Institute for Earth's Physics, Department of Geodynamics, Bucharest
2Reserch Center for Seismology and Volcanology, School of Science, Nagoya University,
Nagoya, Japan
It is deviced to work in two sensitivity fields. The first type, used for
making evident the Earth's periodical tilts, has errors exceeding no more than ±5.10
rad in the relative tilts. The second one, used for making evident the Earth's
non-periodical tilts, has errors between 10
and 10 rad in the relative adjustable tilts depending on the amplitude of the relative
tilts between the
tectonic compartments.
It is completely realized with Romanian components, excepting the Japanese
magnetic displacement transducer (Sony type). It presents particular reliability,
being able to work continuously for almost one year in 100% humidity conditions
in underground geodynamic observatories.
Key words: geodynamic, crust deformation, water-tube tiltmeter, magnetic displacement
transducer, earth tide, underground observatory.
TIPPING BUCKET RAIN GAUGE PCB-85
C. Ionescu, G. Mihalache
Institute for Meteorology and Hydrology, Bucharest
It is intended for remote measurement of liquid and solid precipitation,
up to 200 m.
It consists of a typing bucket transducer, digital display indicator and connecting
cable.
It has good accuracy (0.05%) with a 0.1 l/m
resolution
and is entirely made of indigenous components.
Key words: remote measurement, tipping bucket transducer, digital display,
real time.
WATER CURRENT MEASUREMENT SET CMVA-01
C. Diaconu
Institute for Meteorology and Hydrology, Bucharest
This is a portable set intended for water current speed measurement, necessary
in hydrometrical activities for flow rate calculus.
It consists of a propeller type speed transducer and a digital display read-out.
It has very good precision (2.5%), a large operating range (8 cm/s – 4
cm/s) and easy routine maintenance.
Key words: hydrometrical activities, flow rate, propeller type speed transducer,
digital display.
CUP ANEMOMETER AC-01
O. Enea, V. Simonca
Institute for Meteorology and Hydrology, Bucharest
It is a transducer used for wind speed measurement.
By means of a 3 cup system, it converts wind force to electric pulses using
an optoelectronic sensor.
It can be connected to the wind indicator ADV-01 together with wind vane G-01
to form a complete system for wind parameter measurement.
Key words: anemometer, wind speed, wind force, optoelectronic sensor.
WIND VANE G-O1
O. Enea
Institute for Meteorology and Hydrology, Bucharest
It is a transducer used in wind direction measurement.
It consists of a counterbalanced wind vane coupled to a 2-cursor potentiometer
which has a variable output resistance proportional to the wind direction.
Connected together with cup anemometer AC-01 to the wind indicator ADV-01 it
forms a complete system for wind parameter measurement.
Key words: wind vane, 2-cursor potentiometer, resistance output.
TEMPERATURE INDICATOR TES-01
V. Simonca, T. Popescu
Institute for Meteorology and Hydrology, Bucharest
It enables remote measurement u to 200 m of air temperature.
The temperature transducer is a platinum thermoresistance and the display is
digital.
It has a good linearity, sufficient accuracy (±0.3°C) and it is
made of indigenous components.
Key words: remote measurement, digital display, thermoresistance, linearity,
accuracy.
WIND INDICATOR ADV-01
O. Enea, V. Simonca
Institute for Meteorology and Hydrology, Bucharest
It is used for analog indication of wind parameters.
It measures mean and instantaneous wind speed on 2 scales (0 – 12 cm/s
and 0 – 60 m/s) and instantaneous wind direction (0 – 540°).
It can record measurements by connection to a pen recorder.
It is entirely made of indigenous components.
Key words: analog indication, mean and instantaneous wind speed, pen recorder.