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4th EEGS Meeting
- Conference date: 14 Sep 1998 - 17 Sep 1998
- Location: Barcelona , Spain
- ISBN: 978-94-6282-127-9
- Published: 14 September 1998
21 - 40 of 236 results
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Application of geophysical methods for studies of sites, polluted with old war ammunition
Authors D. Kolarov, W. Spyra and H. PetzoldOn the most part of Brandenburgland during the Second World war some battle collisions passed. As the result on battle fields a lot of different ammunitionfrom shellsplintersof grenades and mines up to non burst airbombshave remained.On the other hand Brandenburg land develops widely coal industry. As is known in south part of Brandenburgland there are some open mines for coal production.The presence of huge amountof ammunition'srests convertsa developmentof new coal deposits to very difficult anddangerousbusiness.
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Environmental mapping using airborne geophysics in Finland
Authors J. Lerssi, T. Jokinen, J. Lohva and R. PuranenGeological Survey of Finland (GSF) has carried out systematic airborne geophysical surveys in Finland since 1951. The second program started in 1972 using a flight altitude of 30-40 meters and line spacing of 200( 100) meters (Lohva et al, 1996; Peltoniemi, 1986). Today 80 % of the country has been measured. The measurements have been made with fixed-wing aircraft. The differential GPS is utilised in navigation. In lowaltitude measurements the following systems are in use: magnetic, gamma radiation and EM. Total magnetic field is measured with a wingtip gradiometer. The horizontal spacing between the magnetic gradiometer sensors is 21 meters. Earth's gamma radiation is measured with a spectrometer which utilises a 41 litres NAI crystal detector. The electromagnetic unit is dual frequency vertical coplanar coil equipment (Poikonen et al, 1998). The frequencies are 3.1 kHz and 14.4 kHz and coil separation is 21.4 m. The survey results are used in mineral exploration and geological mapping, recently also increasingly in environmental applications. GSF has recently conducted aerogeophysical studies of some contaminated are as in Finland (Lerssi et al, 1997). Ämmässuo is a modern, municipallandfill of Helsinki. Landfill area has been mapped three times, first in the national airborne mapping program (1984) before the operation of the landfill started. The 1993 and 1997 monitoring surveys were carried out in the same north-south flight direction as in 1984 but using tighter (100 meters) line spacing. Magnetic anomalies indicate metallic waste and metal constructions. Comparison of 1984, 1993 and 1997 EM maps of Ämmässuo indicate small changes, which have been estimated guantitatively by layer model and 3-D model interpretation. By total radiation map, it was possible to estimate changes of moisture and soil thickness. Lievestuore pulp millled its waste effluent during 1935-1967 to the nearby Koivusensuo mire, where the Lipeälampi waste pond was formed. GSF carried out airborne measurements and ground surveys around the waste pond. The electric conductivity of the efflucent (mainly sodium lignosulfonate) is high and its spreding into the soils can thus be deciphered by electric methods. The AEM anomalies indicate that the most heavily polluted mire area extends north- and southwards from the pond, which was verified by ground conductivity logging (Puranen et al. 1997). Logging and seismie results were also used as a reference material in interpretation and modelling of effluent plume migration.
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Time domain induced polarisation experiments on gasoline contaminated samples
Authors E. Martinho and F. AlmeidaRecently environmental studies have used geophysical methods to delineate oil contaminated sites (Vanhala, 1997). Organic liquids have a high resistivity and thus induction methods are not weil adapted to fine contaminated areas. On the other hand Induction Polarisation has been widely recognised as a useful method for the detecting organic electrical response In field ( Vanhala et al, 1992) and in laboratory (Vanhala et Soininen. 1995) experiments. The later author had a frequency domain approach (SIP) to the problem. On the other hand our initial work carried out in the time domain (Sumner, 1976) and is still in a laboratory phase. In order to study the induced polarisation effect in gasoline contaminated soil samples a GPIB controlled system was developed to carry out electrical measurements as it is shown in Fig.l. This System is able 10 obtain measurements at a rate of ten samples per second. Specially developed porous ceramic electrodes were built to obtain suitable electrical current contacts. Non polarizable electrodes SilverlSilver Chloride were used to measure potential.
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Analysis of ground penetrating measurements of a tar lake
Authors B. Forkman and C. SeegraefIn this paper we combine two relatively new methods to analyse a tar lake. The ground penetrating radar measurement has become a quite important method for the analysis of near-surface conditions. The method is based on the spreading of highfrequency electromagnetic waves and on the validation of Maxwell equations. The wavelet-transform (WT) is used for the analysis of measured data. This transform can be used for the time frequency analysis, for the filtering of data and for the detection of the interference of different signal parts. The WT depends on different functions, the socalled wavetet functions, which have different properties.
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Testfield for studies of sites polluted with old war ammunition with geophysical methods
Authors I. Wolfgang Spyra, S. Reinhardt, H. Petzold and D. KolarovOn most parts of Federal State Brandenburg battle collisions took place during the Second World War. As the result, a lot of different ammunition from shell-splinters of grenades and mines up to non burst airbombs have remained on battle fields. On the other hand. Brandenburg develops widely coal industry. As is known, there are open mines for brown-coal production in the southern part of Brandenburg. The presence of a huge amount of ammunition's rests converts the development of new coal deposits to very difficult and dangerous business.
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Saturation and contamination dependence of electrical properties in the MHz range
Authors C. Urban, J. Schonart and A. WellerThe application of electrical and electromagnetic measurements on geotechnical and environmental problems requires detailed knowledge of the influence of lithology, pore structure and pore filling on the electrical properties of rocks. Former investigations at frequencies up to 1 MHz (Kulenkampff, 1994) have shown that frequency dependent electrical measurements yield especially information about parameters describing the pore structure due to polarization effects caused by electrochemical reactions at the internal surface. Only for highly porous media, pore filling considerably affects the complex conductivity spectra. This is one reason for the strong deviations between the results of measurements and mixing formulas like complex reflection index method (CRIM) or Bruggernann-Hanai-Sen-Shen (BHSS) which ignore surface effects (Urban, 1995). The aim of the presented work is to examine the influence of saturation and contamination of samples of different lithology and known pore structure on the electrical properties in the Mhz range to provide a data base for the interpretation of electromagnetic field measurements. Furthermore, the investigations should result in a quantification of the relation between electrical parameters and pore structure controlling the hydraulic and diffusive transport of pore fluids.
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Measurements and estimates of tracer diffusion in the NW Mediterranean Sea
Authors J. M. Redondo, M. O. Bezerra, M. R. Soler and I. R. CantalapiedraThe eddy diffusivities in the ocean exhibit a large variation and show a marked anisotropy, not only horizontal values are much larger than vertical ones but there is a strong dependenee on the spatial extent of the tracer dye or pollutant. In the case of oil spilIs, these are strongly influenced by the buoyancy and horizontal diffusion depends on ambient factors such as wave activity, wind and currents.
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The main problems of the technogenic radioactive water reservoirs safety on Techa River (South Ural)
Authors G. Batrak and S. SemenovDuring the creation of armament plutonium at the PO Mayak in the South Ural, the acute problem of utilization and storage of low-Ievel liquid nuc1ear wastes arises. The technology allows to discharge them into the open storage reservoirs without hydroisolation of reservoirs, whereas in the USA, bottom and sides of reservoirs are cemented or paved with asphalt. During the exploitation of storage reservoirs, there arises the danger of their overfilling or out-break, as weIl as of seepage through their body and foundation. The problem will be less acute, if the ways of rational reservoir control are found.
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Georadar, electromagnetic, and magnetic studies of a landfill and its host sediments
Authors R. De Iaco, H. Horstmeyer, D. E. Boerner, F. Lehmann and A. GreenMany landfills are currently causing severe environmental problems, such as ground-water contamination. In view of the large number of poorly documented landfills, fast and inexpensive methods for investigating the shallow subsurface are becoming increasingly important. We have tested a variety of non-intrusive geophysical methods at a landfill located within glacio-fluvial sediments in northwestern Switzerland. Three-dimensional georadar, frequency-domain electromagnetic (EM31), and mag net ie surveys have been conducted over part of the landfill and adjacent undisturbed ground. Dense sampling of the subsurface, a self-designed algorithm for sealing the georadar data in a way that suppressed prominent noise, and application of NMO corrections were important steps for obtaining detailed and accurate images of the investigated area. From borehole information, reflections from interfaces between different gravel sheets and from the top of the underlying lacustrine layer could be identified. Timeslices revealed a general SW-NE flow-direction of the ancient river system that deposited the gravels and sands. The lacustrine sediments are an aquitard in this region. Interpolation of the aquitard, an important barrier for contaminants emanating from the landfill, between surveyareas northwest and southeast of the landfill, provide us with an estimate of the maximum dep th of the waste disposal site.
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Evaluation of an old waste disposal site contamination, using electrical methods
Authors F. P. O. Figueiredo and A. I. S. AndradeA case of chemical pollution induced by an abandoned disposal site located on an alluvial plain has been investigated through geophysical prospection. The aim of the geophysical survey was the delimitation of the shape/dimension of the conductive contaminated plume, .which the landfill has been inducing. The plume goes down to a depth that ranges between lOm to 80 mand the resistivity of the contaminated sediments is approximately 50 ohm.m.
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The use of geophysical techniques for the detection and characterization of landfill in areas of urban development
Authors A. Granda and J. C. CamberoThe growth of some Spanish eities has created the need to develop urbanistic projects in its surroundings, on lands that in many cases have been affected by the activity of the city itself, and specifically by the existence of garbage deposits or different kinds of waste products. The nature and characteristics or these waste deposits usually differ in every case, since they may correspond to urban solid waste with a great presence of organic matter, or inert spillings caused by industrial activities. The existence of these deposits is known with a higher or lower degree of accuracy in some cases, while it is absolutely unknown in others, because the old deposits were conditioned for a subsequent use of the ground in a way that after several years it would be impossible to identify their location just by observing the site.
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Non-invasive geophysical mapping of chemical waste deposits and flow-paths
Authors R. D. Ogilvy, D. Beamish, P. I. Meldrum and R. MossA non-invasive geophysical survey has been undertaken to characterise the extent of contamination associated with chemical wastes deposited in dis-used sandstone quarries. The specific aims of the geophysical survey were: - to delineate the concealed edges and base of the quarries prior to the siting of sampling and monitoring boreholes - to assess whether waste fluids had invaded the surrounding sandstones and to map these contaminant migration pathways, prior to intrusive sampling A secondary aim was to assess the general capabilities and reliability of geophysical methods for waste site characterisation in this environment.
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Optimum model in 2D geoelectrical imaging : example from a dump site with high resistivity contrasts
Authors A. I. Olayinka and U. YaramanciModelling and inversion of synthethic data over 2D geologie models have shown that, at high resistivity contrasts, there could be an increase in the model misfit between the inverted model and the true model for successive iterations. Hence, the optimum model is attained at a low iteration number. A case history, from data measured over a waste dump site, is given in which the optimum model is the structure at the second iteration; the inverted resistivities are very low at less than 30 Om down to a depth of about 10 m. These are consistent with the analyses of surface - and ground - water which indicate the presence of a low resistivity contaminant.
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Electrical tomography survey of a landfill site
Authors M. Pokar and M. H. LokeThere are an estimated 230 landfills in Malaysia, some of which are located near communities and water sourees. Besides contamination of ground water due to chemical leachates, gas migration can also be a serious problem. Landfill gases are formed during the decomposition of organic wastes and consists of a mixture of methane (C~), carbon dioxide (C02), nitrogen (N2) and volatile organics. The use of 2D electrical tomography surveys (Griffiths and Barker 1993) to map various features in landfill sites was investigated in this research. Tests with synthetic data for different landfill models were first conducted. Surveys were also carried out to delineate the various fill materials, map leachate movement and gas accumulations. The results from two of the survey lines with possible gas traps are given in this paper.
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The conductivity structure beneath the industrial waste site Mellendorf as derived by radiomagnetotellurics (RMT)
By B. TezkanIn Europe, especially in Germany, the application of geophysical methods to waste site explorat ion becomes inereasingly important since their contribution 1.0 the pollution risk estimation has been recognized. Applied geophysics can offer many techniques for the non-invasive mapping of waste sites and should be considered as a main source of information about interesting borehole locations. Between 1960 and 1989 an automobile company used a sand pit located in Mellendorf near Hannover for the disposal of magnesium dross and other industrial waste. After its recultivation, the waste site was covered by a layer containing soil, sand with gravel and clay. Fig.1 shows a geological stratification beneath the survey area derived from boreholes on the waste site (Renno and Christofzik, 1987).
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Three-dimensional inversion of induced rolarization data from simulated waste
Authors A. Weller, M. Seichter and W. FrangosThe Idaho National Laboratory (INEL) Cold Test Pit (CTP) has been carefully constructed to simulate stored hazardous waste occurrences. In order to test various methods of non-invasive subsurface waste location techniques, a simulated waste pit has been constructed using safe materiaIs, and designed to resembie old waste pits as closely as possible. This Cold Test Pit (CTP) has been investigated by a number of workers using several different methods. The present work was carried out as part of the Electromagnetic Integrated Demonstration (EMID), which also inc1udes an assortment of electromagnetic techniques (pellerin and Alumbaugh, 1997). The CTP was constructed as a 13 x 70 m trench, segmented by transverse berms into cells. The southern-most cell investigated in the EMID project, contains stacked drums and boxes and a variety of randomly positioned barrels, pipes, a large metal tank, etc., this location is referred to as the Large Object Pit (LOP). The buried drums located in the center of the trench inc1ude both cardboard and metal drums containing scrap metal and nonmetallic materiais. The cell is described as being a three-meter waste seam with about 1.5 m of soil cap, thus the depth of the bottom of the waste is about 4.5 m. The cap is composed of c1ay-rich soil trucked in from other areas of the INEL complex. Host material is local soil overlying resistive Snake River basalt.
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Assessment of non controlled land-fillings by geochemical and geophysical methods. Llobregat Delta (Barcelona, Spain).
Authors X. Font, A. Navarro, L. Rivero, A. Casas, J. Noguera and F. MartînezThe problems associated with municipal, abandoned or non-controlled landfills are of general concern, specially because of the interactions between the hazardous content of the leachates derived from them and groundwater. MacFarlane and others (1983) were the pioneers on this type of studies, later on, Cherry and others (1996) did more specific research on heavy metal thermodynamic with emphasis on providing data to assess or validate mathematical models at Borden landfill site (Canada). The main objective of this study was to characterise contaminated sites provoked by noncontrolled sand and gravel extraction quarries filled with urban, construction, industrial and chemical wastes. Using combined geochemical and geophysical data is possible to characterise contamination extension of the groundwater superficial aquifer and to deduce possible implications of water flux through landfillings.
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Geophysical measurements for assessment leakage risk in underground waste storage
By H. MarcakThere are hundreds of kilometres of underground tunnels in the coal mining are as in Upper Silesia and in the copper mining area in Lower Silesia. This empty underground area seems to be very good place for waste deposits. Materials with different levels of toxicity may be stored in these places, when the safety of the place are taken into account. Furthermore according to polish law a system of barriers must be constructed such sites. However, a catastrophic scenario must be considered. In this scenario, the stability of underground caves are disturbed; barriers are destroyed, water fIows into caves and contaminants leave the storage. Consequently, the design of an environmentally safe underground storage system and the control of its safety is achallenge for research workers.
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Diagnosis of waste landfills by infrared thermography
Authors C. Sirieix, L. Rouvreau, L. Bertrand, M. Frappa and C. BloquetIncreasingly strict legislation concerning the management and storage of waste is leading to the creation of a new generation of landfills, as weil as to the remediation or closure of older sites. Thus there is the problem of the long term surveillance of the old sites and the control of the new one. The mass of waste is often a black box in which intense, complex and poorly understood physico-chemical processes occur. If they cannot be controlled, they must be regularly monitored in order to intervene as rapidly as possible if the process warrants it. The thermal activity of a site is directly related to exothermal chemical activity of waste. This chemical activity produces biogases who accumulates in some particular places. Landfill managers have difficulty in characterising site activity and its change with time. There are two phenomena to control : accumulation of biogases like methane and leakage in the new sites and increasing temperature with the risk of fire underground in the old sites. Infrared thermography can be used to establish this thermal activity. We'lI described this two kind of applications.
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Significance of magnetic and induced polarization responses over municipal solid waste facilities
Authors N. Abu-Zeid, M. Marcheti, G. Santarato and M. PaiolaImpacts of improperly managed old Municipal Solid Wastes (MSW), especially those uncontrolled and/or illegal, not only deteriorate the environment by posing it to hazards leading to soil and groundwater eontamination, but also grave the economy as remedy costs ean be very high. Therefore, the best way to proteet the environment is to minimise negative impacts of MSW and to associate them with an efficient monitoring system not only during the feasibility study but also during the whole life of the facility.
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