Geophysical Survey

The storage of large volumes of industrial CO 2 emissions in deep geological formations is one of the most promising climate mitigation options. The long-term retention time and environmental safety of the CO 2 storage are defined by the interaction of the injected CO 2 with the reservoir fluids and rocks. Finding a storage solution that is long lasting, thermodynamically stable and environmentally benign would be ideal. Storage of CO 2 as solid magnesium or calcium carbonates in basaltic rocks may provide such a long-term and thermodynamically stable solution. Basaltic rocks, which primarily consist of magnesium and calcium silicate minerals, provide alkaline earth metals necessary to form solid carbonates. In nature, the carbonization of basaltic rocks occurs in several well-documented settings, such as in the deep ocean crust, through hydrothermal alteration and through surface weathering. The goal of the CarbFix pilot project is to optimize industrial methods for permanent storage of CO 2 in basaltic rocks. The objective is to study the in-situ mineralization of CO 2 and its long term fate. The project involves the capture and separation of flue gases at the Hellisheidi Geothermal Power Plant, the transportation and injection of the CO 2 gas fully dissolved in water at elevated pressures at a depth between 400 and 800 m, as well as the monitoring and verification of the storage. A comprehensive reservoir characterization study is on-going prior to the CO 2 injection, including soil CO 2 flux measurements, geophysical survey and tracer injection tests. Results from the tracer tests show significant tracer dispersion within the target formation, suggesting large surface area for chemical reactions. The large available reservoir volume and surface area in combination with relatively rapid CO 2 -water-rock reactions in basaltic rocks may allow safe and permanent geologic storage of CO 2 on a large scale.

As part of ongoing research into the early medieval sculptural heritage of the Cheshire region, Joanne Kirton and Dr Meggen Gondek of the University of Chester conducted resistivity survey in two fields surrounding St Edith’s Church, Shocklach (NGR SJ 4318 5016). The survey was conducted over three days, October 29 – 31, providing training opportunities for undergraduate students from the University of Chester. Results confirmed the presence of ridge and furrow and several previously unknown features of indeterminate nature.

Anomalies in self potential (SP) are usually explained in terms of geochemical activity. However, there are other sources of current which cause complications in the interpretation. In particular, DC telluric currents can be generated outside the survey region. Contrasts in resistivity cause current channelling and secondary voltages can be induced by leakage. The effect can be demonstrated using network theory and internal sources can be emphasized by subtraction. Joint surveys are required to demonstrate correlations with apparent resistivity.

Recent studies on the Uganda geothermal systems have focused on three geothermal prospects, Katwe, Buranga and Kibiro, all located in the tectonically active and Recent volcanic belt in the Western Rift valley along the border of Uganda and the Democratic Republic of Congo. Geothermal systems and saline and fresh water lakes characterize the Rift Valley. The three areas were chosen for study because of their volcanic and tectonic features that indicate a powerful heat source and high permeability. The objective is to develop geothermal energy as an alternative energy source to hydro and others to meet the energy demand of rural areas in sound environment. The geology and geochemistry results for the surface hot springs indicate that potential geothermal systems exist at depth. The subsurface temperatures of 160-200°C, 200°C, and above 200°C for the Katwe, Buranga and Kibiro prospects, respectively, have been inferred by geothermometry and mixing models. These temperatures are suitab...

Geophysical imaging methods provide solutions to a wide range of environmental and engineering problems: protection of soil and groundwater from contamination; safe disposal of chemical and nuclear waste; geotechnical site testing for underground vaults, subways, dams, ...

Computerized evaluation of Vibroseis similarity test data is the logical consequence of the increasing quality requirements for signal reproducibility and for synchronization of vibrators. The differences in start time and phase as well as an indication of local phasing problems between any two Vibroseis signals can be obtained from an analysis of the difference of their respective phase spectra. This method appears to be accurate and stable with respect to harmonics which usually plague the signals from transducers monitoring the motion of the vibrators'base plates.

Hyderabad is the 5 largest city in India. It has twin cities Viz., Hyderabad and Secunderabad with its suburbs extending up
to 16 miles. The core cities, together with its nine surrounding municipalities are covering an area of 500 square km. The
Hyderabad city discharges about 600 million litres per day untreated sewerage water into Musi River. A stretch of 13 Km
from Nagole /Uppal IDA to Prathap Singaram is chosen as the study area as it is surrounded by more than 25 industries
and their effluents are directly drawn into Musi River (IOSR-JESTFT 2012) [1]. The Musi River water is used for irrigation during
its course of travel which leads to adverse effects on both flora and fauna. The bore well water samples in the radius of 1
km are collected at ten distant places at certain intervals along the Musi River to know the quality parameters. The
collected samples are tested in the Telangana State Ground Water Department (GWD) to access the quality. The
chemical analyses data for both Musi River and bore well water samples are obtained from the GWD for study and
interpretation including its impact. Rainfall data of Uppal Mandal for 10 years beginning 2005 onwards is also collected
from weather station of Acharya N G Ranga Agricultural University, Rajendra Nagar, and Hyderabad for further studies. It
is worthy to note that only Nitrates are recorded as high in all the samples when compared to the BIS standards otherwise,
the remaining parameters are in the normal range [4]. Among 10 stations, 8 stations are having high Nitrate (NO as N) 3
values in which the highest Nitrate value of 35.40 mg/lts is observed from station-5 of R-Krishnaiah Nagar (V), Hayath
Nagar (M) and station-9 i.e. of Submerged Well situated within the radius of 1 km from Thimmaiguda (V), Ghatkesar (M).
Further, it is observed that bore well water samples of 1, 3, 6 and 9 are witnessed with moderate concentration of EC, TDS,
Cl, Cam TH and NO whereas Musi River sample collected near R-Krishnaiah Nagar is witnessed with moderate to high 3
concentrations of EC, TDS, Cl, Na, K, TH and NO . The objective of the article is to minimize the impact of effluents and 3
industrial wastes discharged by the industries by establishing more treatment plants.

Constructive design on inhomogeneous ground often faces geotechnical problems, particularly under ongoing karst processes, namely subsidence or collapses. Careful analysis of this kind of problems by means of different techniques, together with accurate geological models, is needed for correct urban planning. In this work the main results obtained during an urban planning study in the proximities of Zaragoza city (NE Spain) are presented. Several independent approaches give results that can only be clearly interpreted when integrated as a whole. The first approach is related to historical-geomorphological analysis from maps and series of aerial photographs. The second approach is an intensive geophysical survey (GPR, magnetometry, gravimetry, EM). The third approach includes the analysis of subsoil characteristics by means of trenches, boreholes and dynamic penetration tests. Prior studies failed in the correct characterization of this area, mainly because of the difficulties in interpreting the obtained data. The discussion of this work analyzes the sensitivity of techniques and reliability of the obtained results, and the importance of correctly defining the geologicalgeotechnical model. The presented methodology responds to the main potential problems to be analyzed in complex alluvial environments linked to karst activity and can be applied in similar contexts where different approaches must be integrated to obtain realistic geological models.

The paper presents the preliminary results of an integrated multidiscipliary research project concerning the urban area of the modern Durres (ancient Dyrrachium). Here a joint Italian and Albanian researcher are starting preliminary investigations on the place of an ancient roman villa placed in the urban centre of the modern town. In a initial phase are offering interesting results the use of a rich multitemporal remote sensing data-set, historical aerial photos of 1920s and 1930s, photos of USA spy satellites of 1960s and 1970s (Corona KH-4A and KH-4B), and very high resolution satellite imagery. The historical aerial documentation is very rich and includes aerial photogrammetrich flights of two Italian Institutions: the private company SARA - Società Anonima Rilevamenti Aerofotogrammetrici in Rome (1928) and the IGM - Istituto Geografico Militare (1936, 1937 e 1941), which flew on Durres for purposes of cartographic production and military. These photos offer an image of the city before the urban expansion after the Second World War and in recent decades, progressively documented by satellite images of the 1960s-1970s and recent years. They enable a reconstruction of the ancient topography of the urban area, even with the possibility of detailed analysis, as in the case of the the Roman villa, nowadays buried under a modern garden, but also investigated with a GPR survey, in order to rebuild its plan and contextualize the villa in relation to the urban area of the ancient Dyrrachium.

Traditional electrode arrays such Wenner-Schlumberger or dipole-dipole are still widely used thanks to their well-known properties but the array configurations are generally not optimized for multi-channel resistivity measures. Synthetic datasets relating to four different arrays, dipole-dipole (DD), pole-dipole (PD), Wenner-Schlumberger (WS) and a modified version of multiple gradient (MG), have been made for a systematic comparison between 2D resistivity models and their inverted images. Different sets of array configurations generated from simple combinations of geometric parameters (potential dipole lengths and dipole separation factors) were tested with synthetic and field data sets, even considering the influence of errors and the acquisition velocity. The purpose is to establish array configurations capable to provide reliable results but, at the same time, not involving excessive survey costs, even linked to the acquiring time and therefore to the number of current dipoles used. For DD, PD and WS arrays a progression of different datasets were considered increasing the number of current dipoles trying to get about the same amount of measures. A multi-coverage MG array configuration is proposed by increasing the lateral coverage and so the number of current dipoles. Noise simulating errors both on the electrode positions and on the electric potential was added. The array configurations have been tested on field data acquired in the landfill site of Bellolampo (Palermo, Italy), to detect and locate the leachate plumes and to identify the HDPE bottom of the landfill. The inversion results were compared using a quantitative analysis of data misfit, relative model resolution and model misfit. The results show that the trends of the first two parameters are linked on the array configuration and that a cumulative analysis of these parameters can help to choose the best array configuration in order to obtain a good resolution and reliability of a survey, according to generally short acquisition times.

Spatial technology is integral to how archaeologists collect, store, analyze, and represent information in digital data sets. Recent advances have improved our ability to look for and identify archaeological remains and have increased the size and complexity of our data sets. In this review we outline trends in visualization, data management, archaeological prospecting, modeling, and spatial analysis, as well as key advances in hardware and software. Due to developments in education, information technology, and landscape archaeology, the implementation of spatial technology has begun to move beyond superficial applications and is no longer limited to environmental deterministic approaches. In the future, spatial technology will increasingly change archaeology in ways that will enable us to become better practitioners, scholars, and stewards.

Electromagnetic (EM) profi ling and Vertical Electrical Sounding (VES) studies were carried out for groundwater exploration in the Twifo-Hemang Lower Denkyira Districts of Ghana. These two geophysical methods were used for exploring the groundwater potentials beneath Achiase Community, Mbaa Mpe Hia Community and Moseaso Community. This paper seeks to encourage the use of inversion for interpreting electromagnetic data rather than the usual qualitative interpretation method using line graphs and also the use of apparent resistivity maps as 2D pseudo resistivity maps to support interpretations of the 1D inversion results (in cases where the available budget could not permit 2D and or 3D inversion). These would help in enhancement of obtained results, reduce ambiguity and help decision making. The EM results revealed that; the three communities are underlain by two layers with the fi rst layer having the thickness range between 2 to 10 m and the second layer is a half space. The results from VES studies indicate that; Achiase Community and Mbaa Mpe Hia No. 2 community are underlain by three geoelectrical layers and Moseaso Community is underlain by four geoelectrical layers. On the basis of this study the Moseaso Community is ranked highest in terms of groundwater potential followed by the Achiase community and fi nally the Mbaa Mpe Hia No.2 Community. Several sites were recommended for drilling boreholes for water supply in these communities.

Numerous studies have proved the connection between low-amplitude local anomalies of gravity and magnetic field with oil and gas deposits in both platform and geosynclinal areas. In theoretical and experimental studies, gravity and magnetic prospecting methods for forecasting oil and gas accumulations in various geological structures have been used. They show out that oil and gas deposits located in different oil and gas regions of the world are noted discoveries with geophysical methods, including gravitational and magnetic fields. As a result, new exploration signs have identified the appearance of local gravitational and magnetic minima of various intensities above the productive parts of the structures. It has been established that the first physical and geological prerequisites for using gravimetry and magnetometry to explore hydrocarbon deposits in Azerbaijan are decreases in the density and magnetic susceptibility of rocks in the area of the deposit. Gravity-magnetic studies carried out in the Kura Depression show that over the known deposits (Muradkhanly, Jafarly, Tarsdallar, Gazanbulag, Babazanan, Bandovan, etc.), gravitational and magnetic minima of 0.2-0.8 mGal and 20-30 nT. The physical and geological properties of the Muradkhanli field have been modeled by studying some of the physical parameters in the Middle Kura Depression of Azerbaijan (the changes in the magnetic susceptibility, temperature, and density of rocks in the subvertical zone above and below the reservoir). In this study, the results of gravimetric and magnetometric studies performed for oil and gas deposits on the areas of Arabkubaly, Naftalan, Northern Naftalan, Gedakboz of Azerbaijan are presented. Consequently, the outcomes of experimental and systematic work carried out in the areas of Middle Kura Depression and Lower Kura Depression show the effectiveness of gravity-magnetic methods.
Keywords: Oil and gas exploration, Gravity, Magnetic, Geophysical exploration, Hydrocarbon deposit

Combinations of hydrogeological and geophysical data are increasingly used in hydrogeological site characterization. Although a wide range of methods to combine hydrogeological and geophysical data are presented in the literature, most investigations focus on development or application of a single method, and there have been few attempts to compare different methods. Here we review the choices that must be made in any hydrogeophysical parameter estimation effort, including model parameterization, the petrophysical relationship, and a-priori information. We distinguish between three classes of hydrogeophysical parameter estimation: direct mapping; integration methods; and joint inversion methods. We provide five examples that illustrate the different merits of those classes of methods. We conclude that direct mapping and integration methods, such as co-kriging, have proven their worth in hydrogeophysical parameter estimation. However, we argue that joint inversion methods might provide fundamental improvements because such methods facilitate information sharing and they form a consistent framework for addressing uncertainty and the worth of different data types.

The National Geotechnical Experimentation Site at Opelika, Alabama is underlain by residual silts and sands derived from the weathering of schist and gneiss of the Piedmont Geologic Province. Site characterization by in-situ tests has included an extensive series of cone and piezocone penetrometer soundings supplemented with standard penetration, flat plate dilatometer, pre-bored and full-displacement pressuremeter, and borehole shear. Geophysical surveys have been completed by crosshole, surface wave, and downhole tests. Complementary laboratory testing on split-barrel drive samples and continuous geoprobe samples have consisted of index, moisture, plasticity, gradation, & hydrometer analyses. Undisturbed tube samples have been subjected to triaxial, resonant column, permeability, and oedometer loading. Piedmont residual soils are unusual in that they exhibit behavioral facets characteristic of both clay and sand, thus creating a dichotomy in practice in selecting undrained versus drained soil parameters for analysis.

The Sudanese rift structures form intracontinental basins, bordered on all sides by anorogenic terrain. These basins are seen as the result of a multistructural system of rifts which appear to have been activated several times since the Palaeozoic. Improved methods of dating and extensive geophysical surveys have led to a better understanding of the mobile belts and the Basement rocks in the general environs of the basins, and of the elevated blocks and highs surrounding the sedimentary basins. Detailed mapping and extensive drilling in the sedimentary basins led to a better understanding of the Phanerozoic. The rapid rate of uplift and subsidence have assisted in the rapid accumulation and filling of the basins with unconsolidated sediments, ranging from a few hundred metres to some thousand metres. The rift structures contain sediments of several age groups, origin and mode of deposition. Some of them are as old as the Palaeozoic passing through to Mesozoic, Tertiary and Quaternary (Bahr El Arab rift and Blue Nile rift). The thickness of the Tertiary sediments exceeds 15 km in Bahr El Arab rift.

1. the migmatite-gneiss complex (fig. 2), 2. the shist belt (metasediments and metavolcanic rocks) 3. the older granite / the Pan African Granitoids 4. unmetamorphosed minor acid and basic rocks / intrusions. The migmatitie-gneiss complex (fig. ) also termed "migmatite-gneiss-quartzite complex", it is has an age that ranges from Pan-African to Eburnean, and it has a heterogeneous assemblage comprising migmatites, orthogneises, paragneisses, and a series of basic and ultrabasic metamorphosed rocks, it covers over 30% of the total surface area of Nigeria .

This paper will take you to the beginning of a completely new field investigation over a completely new area with some unprecedented information and some common but interesting information. This paper may be considered as a complete sketch over our field investigation area which is NNW-SSE trending Bandarban anticline situated at Bandarban, Chittagong. The study area is located in between 22⁰04'40" and 22⁰13'45" north latitudes and in between 92⁰07'15" and 92⁰14'45" east longitudes and is a part of the Western subdivision of the Indo-Burman fold range.

Kajian arkeologi di Lembah Mansuli, Lahad Datu, Sabah Ielah menemukan
dua tapak Paleolitik, iaitu Gua Samang Buat dan tapak terbuka Mansuli. Isu utama
di Gua Samang Buat ialah berapakah kedalaman sedimen di dalamgua ini selepas
ekskavasi empat meter masih belum menemui lantai gua. Manakala isu utama di
tapak terbuka Mansuli ialah interpretasi paleoalamnya yang dikatakan bersekitaran
tasik kuno. Maka, kaedah geoftzik telah digunakan untuk cuba menjawab isu ini.
Penggunaan kaedah geofizik di Lembah Mansuli telah berjaya membantu
mengenalpasti ketebalan sedimen di Gua Samang Buat dan membantu membina
paleoalam untuk Lembah Mammli. Ketebalan sedimen gua di Gua Samang Buat
yang boleh di' ekskavasi ialah 12 m di Gua 1 dan 5 m di Gua 2. Data ini
mencadangkan secara relatifberkemungkinan kita boleh menemui lapisan berusia
138,000 tahun dahulu di Gua Samang Buat berdq~rkan usia 46,000 untuk
kedalaman 4 m. Kajian gwifizik di Lembah Mansuli pula mendedahkan wujud
tasik kuno dan sa/iran sungai kuno di Lembah Mansuli. Malah daripada survei
tersebut, ianya juga mendedahkan kemungkinan wujud dua teres tasik kuno. Modelanomali graviti dan magnet juga turut menghasilkan hentuk tasik.

This book is written mainly for university students taking a course on gravity as one of the methods used in geophysical exploration. It is designed to be an introductory text book that deals with the basic concepts underlying the application of the Earth gravitational field in the exploration of the subsurface
geological changes and in prospecting of petroleum and other mineral deposits.
As it is familiar with the exploration geophysicists, this subject is fully dealt with in many original authentic internationally-known text books. In this publication, no new subjects were added to those found in the other standard books which are well known in the geophysical library. In fact these and other related scientific papers and research reports formed the solid references for the present work.
There is, however, a difference in the design and presentation approach. The essential publications, used as references, are listed at the end of the book. The main feature of this work is being concise and logically sequenced. The objective was to present the subject in a simple and clear way avoiding excessive descriptions and unnecessary lengthy comments. For this reason the text was provided with numerous illustration figures for extra clarification.
The book consists of twelve chapters. The first five chapters cover the theoretical aspect of the subject including the gravitational attraction, shape of the planet Earth and nature of the gravity variations, which forms the basis for the
exploration capability of the method. The following five chapters deal with measuring instruments, field surveying techniques, data processing, concept of the gravity anomaly and interpretation. A closely associated with gravity anomaly is the phenomenon of isostasy. This was presented in chapter 10. Some modern aspects of the method were covered in chapter 11 and in the last chapter 12 actual gravity field-surveys were reviewed. The first case history is an actual field survey conducted by one of the authors (Hamid Alsadi) in the south-west England in 1965-1966 and the others (by Zuhair Al-Sheikh and Ezzadin N. Baban) were carried out in Iraqi territories. These are included here to serve the purpose of showing how a real gravity surveying is carried out in practice under
actual field and processing environments.
As always in any publication material, there is always a room for improvement if extra time and effort has been allocated. From personal experience this is an endless process. However, this book is no exception to this rule. With feed-backs from future users of the book it is hoped to make the improvement changes needed that will be incorporated in future editions.

Overdeepened valleys and basins are the most interesting features of former glacial action in Alpine areas. Understanding the formation of such phenomena are not only a scientific task but also an important challenge for a society increasingly exploiting sustainable natural resources even in remote areas. The feasibility of hydrogeological or geothermal projects, for instance, depends on the bedrock depth and the sedimentary infill of such valleys. Generally, overdeepened valleys are formed in areas where the ice discharge was high, such as near the equilibrium line, at valley junctions, or at narrowings of the valley profile. The long known overdeepened tongue basins in the Eastern Alps are regarded as typical examples of the impact of high ice flow velocities combined with increased debris load and running water under hydrostatic pressure around the former (LGM, and older glaciations) equilibrium lines (e.g. van Husen, 2000). However, within a highly dissected mountain topography ...

The geophysical assessment of groundwater in Igarra, Edo state, south western Nigeria which lies between latitude 7015IN to 7020IN and longitude 604IE to 608IE was carried out with the aim of delineating probable areas of high groundwater potential. The area falls within the Crystalline Basement Complex of southwestern Nigeria. The geophysical investigation involves the very low frequency electromagnetic (VLF-EM) and Vertical Electrical Sounding (VES) methods. The VLF EM survey was at 5m interval along five traverses ranging from 100South to 100North (i.e. 200m in length) using ABEM WADI VLF-EM unit. The VLF-EM survey was used to delineate areas with conductive/fractured zones by plotting both the raw real and filtered real against the distance and using the Karous-Hjelt to determine the depths. Thirteen (13) vertical electrical soundings were acquired along three (3) traverses using the Schlumberger array which were carried out with the use of Ohmega resistivity meter. The groundwater potential of the area has been based on aquifer geoelectric parameters obtained from VES interpretation results, isopach and isoresistivity map. The result of VLF-EM survey along its traverse was used in delineating high conductive or fractured zones. The VLF profiles showed maximum peak at both the positive and negative region. Prominent positive filtered real peak usually signifies fractures, contact zones or presence of clayey materials (F1, F2, F3a, F3b and F5). Areas where both the raw real and filtered real positive peak coincides signifies a thick overburden (T1, T2a, T2b and T4) while were both negative peaks coincides signifies a shallow overburden (S2 and S5). The VES results showed three (3) to four (4) geoelectric layers inferred as topsoil, saturated layer (clayey), weathered layer and fractured/fresh basement. The combination of these two methods, therefore, helped in resolving the prospecting location for the groundwater yield in the study area. The thickness of the top soil ranged from 0.1 to 1.3m while the resistivity values varied from 51 to 47 Ωm. the saturated layer thickness varied between 0.1 and 1.3m while its resistivity ranged between 9.8 to 52 Ωm. The weathered and fractured aquifers constituted the main aquifer units having thickness of 0.5 to 87.3m. The fractured/fresh basement resistivity ranged between 8825.8 Ωm to infinity. The overburden thickness ranged between 3.5 to 91.9m. The combination of electromagnetic profiling and vertical electrical resistivity surveys in the study area has contributed to a better understanding of the groundwater occurrence in this part of basement complex of Igarra, Edo state. Integration of VLF-EM and electrical resistivity sounding results enabled identification of good site for productive borehole and groundwater in a typical crystalline terrain as the studied area.

Many years ago, geophysical surveys (gravity and aeromagnetic) were initiated for economic investigation and recently the analysis of gravity and magnetic anomalies are used as a powerful tool for the geological mapping. The present study is based on various filtered maps of gravity and aeromagnetic anomalies of north-eastern Morocco (NEM) in order to highlight its main structural features. Filtering techniques such as horizontal gradient, upward continuation and Euler deconvolution were used to map structural lineaments in NEM. The obtained structural map is consistent with many faults already recognized or supposed by traditional structural studies, and highlights new major accidents by specifying their layout and dips.

Electrical resistivity of the soil can be considered as a proxy for the spatial and temporal variability of many other soil physical properties (i.e. structure, water content, or fluid composition). Because the method is non-destructive and very sensitive, it offers a very attractive tool for describing the subsurface properties without digging. It has been already applied in various contexts like : groundwater exploration, landfill and solute transfer delineation, agronomical management by identifying areas of excessive compaction or soil horizon thickness and bedrock depth, and at least assessing the soil hydrological properties. The surveys, depending on the areas heterogeneities can be performed in one-, two-or three-dimensions and also at different scales resolution from the centimetric scale to the regional scale. In this review, based on many electrical resistivity surveys, we expose the theory and the basic principles of the method, we overview the variation of electrical resistivity as a function of soil properties, we listed the main electrical device to performed one-, two-or three-dimensional surveys, and explain the basic principles of the data interpretation. At least, we discuss the main advantages and limits of the method.

Salt water intrusions of marine origin are a major cause of contamination for coastal fresh water aquifers. They are generated mainly by the uncontrolled exploitation of fresh water in pumping stations from coastal areas. In Romania, such marine intrusions have occurred in the southern part of Black Sea's coastline, in the area of Vama Veche and Costineşti resorts, contaminating the main aquifers which are hosted within Sarmatian (late Middle Miocene) lumachelic and oolitic limestones. Fresh water exploitation management requires the identification, mapping and monitoring of marine intrusions. These are achievable by means of an adequate application of geoelectrical methods, because sea water intrusions lead to major variations of the aquifers resistivity. Apparent resistivity surveys such as electrical profiling and vertical electrical sounding (VES) are able to delineate the areal extent of these intrusions and to identify the approximate depth of the fresh water/salt water interface. Assuming the subsurface geology consists of horizontal and homogeneous layers, the VES apparent resistivity data can be interpreted in terms of layer thicknesses and true resistivities, i.e. a one-dimensional (1-D) geoelectrical model with a stepwise variation of true resistivity with depth. The optimal model is obtained by repeated forward modeling trials or through the inversion of measured apparent resistivities.
This paper presents an algorithm and a set of software applications for the forward modeling of VES apparent resistivity curves, by using digital linear filtering. The codes were elaborated in MATLAB programming environment and allow the calculation of the theoretical VES response for horizontally-layered geological media with virtually unlimited number of layers, including layers with a quasi-continuous resistivity variation. The latter option can be used to simulate particular hydrogeological situations regarding the sea water intrusions in fresh water aquifers, which often show a mixing/transition zone of variable salinity and resistivity. The interpretation of VES curves recorded in Vama Veche area by using the elaborated software indicates that the sea water intrusion occurs at more than 50 m depth. This agrees with water wells tests which confirm the presence of salt water at 40–60 m depth in that area.

Satala is one of the last great military centers in the Roman East available for archaeological and historical investigations. This archaeological site is situated on the crossing of two singularly important routes in North-East Asia Minor. Only little archaeological fieldwork in and around Satala has so far been carried out, thus delimiting our knowledge of the site and its role