Gravity Measurements Research Articles

4–8 GHz Fourier-domain Searches for Galactic Center Pulsars

The Galactic Center (GC), with its high density of massive stars, is a promising target for radio transient searches. In particular, the discovery and timing of a pulsar orbiting the central supermassive black hole (SMBH) of our galaxy will enable stringent strong-field tests of gravity and accurate measurements of SMBH properties. We performed multiepoch 4–8 GHz observations of the inner ≈15 pc of our galaxy using the Robert C. Byrd Green Bank Telescope in 2019 August–September. Our investigations constitute the most sensitive 4–8 GHz GC pulsar survey conducted to date, reaching down to a 6.1 GHz pseudo-luminosity threshold of ≈1 mJy kpc2 for a pulse duty cycle of 2.5%. We searched our data in the Fourier domain for periodic signals incorporating a constant or linearly changing line-of-sight pulsar acceleration. We report the successful detection of the GC magnetar PSR J1745−2900 in our data. Our pulsar searches yielded a nondetection of novel periodic astrophysical emissions above a 6σ detection threshold in harmonic-summed power spectra. We reconcile our nondetection of GC pulsars with inadequate sensitivity to a likely GC pulsar population dominated by millisecond pulsars. Alternatively, close encounters with compact objects in the dense GC environment may scatter pulsars away from the GC. The dense central interstellar medium may also favorably produce magnetars over pulsars.

The impact of multi-sensor land data assimilation on river discharge estimation

River discharge is one of the most critical renewable water resources. Accurately estimating river discharge with land surface models (LSMs) remains challenging due to the difficulty in estimating land water storages such as snow, soil moisture, and groundwater. While data assimilation (DA) ingesting optical, microwave, and gravity measurements from space can help constrain theses storage states, its impacts on runoff and eventually river discharge are not fully understood. Here, by taking advantage of recently published land DA results that jointly assimilate eight different combinations of observations from the Moderate Resolution Imaging Spectroradiometer (MODIS), Gravity Recovery and Climate Experiment (GRACE), and Advanced Microwave Scanning Radiometer for EOS (AMSR-E), we quantify to what degree multi-sensor land DA improves the river discharge simulation skills over 40 global river basins, and investigate the complementary strengths of different satellite measurements on river discharge. To be more specific, river discharge is updated by feeding gridded runoff from the eight multi-sensor DA simulations into a vector-based river routing model named the Routing Application for Parallel computatIon of Discharge (RAPID). Our modeling results, including 7-year simulations at 177,458 river reaches globally, are used to study the seasonal to interannual variability of river discharge. It is found that assimilating GRACE has the greatest impact on global runoff patterns, leading to the most pronounced improvements in spatial river discharge in the middle and high latitudes with the R2 increased by 0.16. The seasonal variation of spatial discharge is most skillful during the boreal summer. However, our evaluation also shows model and DA still struggle to generate reasonable variability and averaged discharge over permafrost regions. By assessing how different satellites add value to discharge forecasts, this study paves the way for more advanced multi-sensor satellite data assimilation to predict the terrestrial hydrological cycle.

Moho depths for Antarctica Region by the inversion of ground-based gravity data

SUMMARYIn the last years the scientific literature has been enriched with new models of the Moho depth in the Antarctica Continent derived by the seismic reflection technique and refraction profiles, receiver functions and seismic surface waves, but also by gravimetric observations over the continent. In particular, the gravity satellite missions of the last two decades have provided data in this remote region of the Earth and have allowed the investigation of the crust properties. Meanwhile, other important contributions in this direction has been given by the fourth International Polar Year (IPY, 2007–2008) which started seismographic and geodetic networks of unprecedented duration and scale, including airborne gravimetry over largely unexplored Antarctic frontiers. In this study, a new model for the Antarctica Moho depths is proposed. This new estimation is based on no satellite gravity measures, thanks to the availability of the gravity database ANTGG2015, that collects gravity data from ground-base, airborne and shipborne campaigns. In this new estimate of the Moho depths the contribution of the gravity measures has been maximized reducing any correction of the gravity measures and avoiding constraints of the solution to seismological observations and to geological evidence. With this approach a pure gravimetric solution has been determined. The model obtained is pretty in agreement with other Moho models and thanks to the use of independent data it can be exploited also for cross-validating different Moho depths solutions.

SELECTION OF AN OPTIMUM GLOBAL GRAVITATIONAL MODEL FOR GEOLOGICAL MAPPING OF AFIKPO AND ANAMBRA BASINS IN NIGERIA

Combined Global Gravitational Models (GGMs) are being used in numerous geoscience applications, most notably for gravimetric geoid modeling (in geodesy) and for geological mapping and geophysical explorations (in the Earth’s sciences). The aim of this study is to evaluate the suitability of different combined GGMs that could be used for the geological mapping of middle belt region and Southeastern Nigeria. For this purpose, we digitized geological maps of Afikpo and Anambra Basins to evaluate geological signatures implied by gravity field quantities (Bouguer gravity anomalies and vertical gravity gradient) derived from the EGM2008, EIGEN-6C4, GECO, SGG-UGM-1 and XGM2019e_2159 gravitational models. We also stochastically evaluated the performance of these GGMs by computing their Root-Mean-Square (RMS) fit with ground-based gravity measurements. The results show that the EIGEN-6C4 and XGM2019e_2159 models have the best RMS fit with the ground-based gravity data. A spatial pattern in Bouguer gravity maps (compiled using these two models) generally closely agrees with a geological configuration of the basins, while also exhibiting some more detailed geological features. Interestingly, however, despite the XGM2019e has the best fit and better mimics major geological features, the gravity image from this model does not exhibit a sediment signature in a portion of the Afikpo basin. A possible reason is that the topographic information used to recover a higher-frequency gravity spectrum of this model might suppress a gravitational signature of subsurface density structures. A comprehensive interpretation of geological features thus requires a careful analysis of existing GGMs, terrestrial gravity data as well as all other reliable geological and geophysical information.

Study on room-temperature effect of a superconducting gravimeter prototype

PurposeThis study aims to reveal the room-temperature effect of a superconducting gravimeter prototype, which will guide its subsequent optimization to improve its gravimetric measurement accuracy.Design/methodology/approachWithout leveling, the prototype output signal, tilt data and room temperature were measured under steady operating conditions. After analyzing the correlations of the three data sets, the residuals of the prototype’s output signal were compensated using the tilt data and the geodynamic effects (ocean tide loading, atmospheric loading and the gravitational effect of polar motion) were then corrected.FindingsThe remaining residuals after correction may be caused by small tilt variations that are due to the sensor chamber temperature and radiation shield temperature changes. These small tilt variations were submerged in the tilt signal noise. Although the peak-to-peak noise of the tiltmeter does not exceed 15 µrad, it can still produce gravimetric deviations above 60 µGal when the prototype is significantly tilted.Originality/valueThis study analyzes in detail the room-temperature effect of a superconducting gravimeter prototype, introduces the tilt effect of the relative gravimeters to compensate for the gravimetric deviations and emphasizes that the improvement of fine leveling and the accuracy of the tiltmeter are key requirements for the prototype to perform high-accuracy gravity measurement tasks.

Automated Urinal-Based Specific Gravity Measurement Device for Real-Time Hydration Monitoring in Male Athletes.

Acute and chronic hydration status is important for athlete safety and performance and is frequently measured by sports scientists and performance staff in team environments via urinalysis. However, the time required for urine collection, staff testing, and reporting often delays immediate reporting and personalized nutrition insight in situations of acute hydration management before training or competition. Furthermore, the burdensome urine collection and testing process often renders chronic hydration monitoring sporadic or non-existent in real-world settings. An automated urinalysis device (InFlow) was developed to measure specific gravity, an index of hydration status, in real-time during urination. The device was strongly correlated to optical refractometry with a mean absolute error of 0.0029 (±0.0021). Our results show this device provides a novel and useful approach for real-time hydration status via urinalysis for male athletes in team environments with high testing frequency demands.

Geophysical reconnaissance of the western basin of the Plaine du Nord aquifer, Haiti

A geophysical reconnaissance was conducted to support aquifer characterization and evaluate groundwater potential in the western portion of the Plaine du Nord aquifer to provision the growing water demands of the city of Cap-Haitien in the Republic of Haiti. Hybrid-source audio-magnetotelluric (HSAMT) soundings and gravity measurements were collected to support the Government of Haiti in sourcing additional water supplies for the city. The Plaine du Nord aquifer is poorly characterized considering it is one of Haiti’s largest aquifers, few drilling logs are available, and only one borehole has investigated the deeper extents of the aquifer. HSAMT supports depth profiling of subsurface resistivity, which supports interpretations of geological strata and groundwater conditions. Gravity measurements allow for complementary mapping of Earth density anomalies and contrasts, which assist in interpreting aquifer thicknesses or depth to bedrock. Pairing HSAMT and gravity methods permitted both an estimation of aquifer thickness and relative changes in sediment characteristics. Gravity results allowed for the mapping of aquifer thickness across the study area, with interpreted thickness greater than 300 m in the coastal zone. HSAMT results cross correlated with available well records and enabled the delineation of zones with increased groundwater potential. The results of the combined methods indicate groundwater storage potential of freshwater in deeper alluvium and emphasize the importance of strengthening resource characterization, modelling and monitoring to guide sustainable resource development and management.

Interdisciplinary fracture network characterization in the crystalline basement: a case study from the Southern Odenwald, SW Germany

Abstract. The crystalline basement is considered a ubiquitous and almost inexhaustible source of geothermal energy in the Upper Rhine Graben (URG) and other regions worldwide. The hydraulic properties of the basement, which are one of the key factors in the productivity of geothermal power plants, are primarily controlled by hydraulically active faults and fractures. While the most accurate in situ information about the general fracture network is obtained from image logs of deep boreholes, such data are generally sparse and costly and thus often not openly accessible. To circumvent this problem, an outcrop analogue study was conducted with interdisciplinary geoscientific methods in the Tromm Granite, located in the southern Odenwald at the northeastern margin of the URG. Using light detection and ranging (lidar) scanning, the key characteristics of the fracture network were extracted in a total of five outcrops; these were additionally complemented by lineament analysis of two different digital elevation models (DEMs). Based on this, discrete fracture network (DFN) models were developed to calculate equivalent permeability tensors under assumed reservoir conditions. The influences of different parameters, such as fracture orientation, density, aperture and mineralization, were investigated. In addition, extensive gravity and radon measurements were carried out in the study area, allowing fault zones with naturally increased porosity and permeability to be mapped. Gravity anomalies served as input data for a stochastic density inversion, through which areas of potentially increased open porosity were identified. A laterally heterogeneous fracture network characterizes the Tromm Granite, with the highest natural permeabilities expected at the pluton margin, due to the influence of large shear and fault zones.

Gravity Forward and Inversion Modelling in Improving the Geology Model of the Flank Volcanic Structure

Cross-sections of volcanic structures are generally constructed using existing surface rock data. The detailed subsurface is not accessible because of a limited approach; as a result, precision is less accurate. Geophysical data obtained from surface gravity measurements will improve this phenomenon based on the response of density variation through forward and inverse modelling. The joint interpretation will make it possible to improve the subsurface model and to apply it in volcano deposits that experience a throw. Gravity data acquisition is 200 points over an area of 16 × 14 square kilometres. An anomaly study will focus on near-surface phenomena, where modelling shows that inversion needs to be enhanced by mesh refinement. In addition, forward modelling renders the model more realistic. The results show, the fault reaches a half km. It is not seen in the geology section, and the density variation shows 0.3 grams/cc. This density change is interpreted for the pyroclastic in the depression segment. Fumaroles may interpret as the water percolating pathway from the peak through the flank structure. The meteoric water flows inside the volcanic deposits and the fault plane is the ends of the meteoric water reaching the outside.

A Comparison Between Sea‐Bottom Gravity and Satellite Altimeter‐Derived Gravity in Coastal Environments: A Case Study of the Gulf of Manfredonia (SW Adriatic Sea)

AbstractThe marine gravity field derived from satellite altimetry is generally biased in coastal areas by signals back‐scattered from the adjacent land. As a result, the derived gravity anomalies are generally unreliable for geophysical and geological interpretations of near‐shore environments. We compared two different altimetry models with sea‐bottom gravity measurements acquired along the Italian coast to quantify the errors generated by reflections from onshore areas and verify the quality of the geologic models inferred from gravity data. We focused on the Gulf of Manfredonia, in the SE sector of the Adriatic Sea, where (a) two different sea‐bottom gravity surveys have been conducted over the years, (b) the bathymetry is mainly flat, and (c) seismic data has revealed a prominent carbonate ridge covered by hundreds of meters of Oligocene‐Quaternary sediments. Gravity field derivatives have been used to enhance both deep geological contacts and coastal noise. The analyses point to a ringing noise that degrades the altimeter signals up to 17 km from the coast. Differences between observations and gravity calculated from a geological model and constrained by seismic data show that all the data sets investigated register approximately the same interference patterns associated with the Gondola Fault Zone. This study shows the potential for integrating gravity anomalies from satellite altimetry with high‐resolution near‐shore data, such as that provided by sea‐bottom gravity network available around the Italian coasts. Future applications will use this technique to improve the analysis of the connections between marine and inland geology in transitional areas.

Measuring and adjusting the distance between the center of mass and optical center of a free-falling body in an absolute gravimeter

In an absolute gravimeter based on optical interferometry, the rotation of a falling body leads to inaccurate gravity measurement. By arranging the center of mass (COM) of the falling body together with its optical center (OC), the rotation error can be minimized rapidly. An optical measurement system with a two-stage pendulum structure is proposed to measure the distance between the COM and the OC of the falling body. The displacement of the OC is measured by an orthogonal interferometer while the falling body twists around the torsion wire, and the rotation angle of the falling body is measured synchronously by a photoelectric autocollimator. It is proved that a twist of the falling body by 2.4 degrees leads to a significant offset of about 0.2 nm along the direction of the laser beam. This results in a limit error of the measurement of the distance between the OC and the COM less than 1 μm. Thus, the rotation error in absolute gravity measurement is reduced to 0.07 μGal.

Gambaran Berat Jenis Urin Dan Kadar Protein Urin Pada Ibu Hamil Di Upk Puskesmas Kampung Dalam Pontianak Timur

Laboratory examinations are carried out to determine diseases that can affect pregnancy, one of the tests carried out is routine urine. The presence of the hormone HCG (Human Chorionic Gonadotrophin) in the urine can be used for a pregnancy test. Kidney function, can be known through a protein test in the urine, the presence of protein in the urine leads to pre-eclampsia in pregnant women. High urine specific gravity can be caused by lack of fluid consumption, the presence of sugar in the urine, and protein in the urine (usually in people with kidney disorders) or certain medications. This study aims to describe the description of urine specific gravity and urine protein levels in pregnant women in the UPK Puskesmas Kampung Dalam, Pontianak Timur. This is a descriptive survey research using the accidental sampling technique. Measurements and observations of research variables were measurements of urine specific gravity and urine protein content which were carried out at the UPK Laboratory of the Kampung Dalam Puskesmas, Pontianak Timur. The sample used is a urine sample when pregnant women who meet predetermined criteria, the examination is carried out using a Urine Analyzer. Respondents of this study found 30 people. The results of 30 respondents pregnant women measuring urine specific gravity whose normal limit is 1,005-1,030 obtained urine specific gravity of 1,010 as many as 6 respondents (20%), 1,015 as many as 9 respondents (30%), 1,020 as many as 2 respondents (6,7% ). 1,025 as many as 6 respondents (20%), and 1,030 as many as 7 respondents (23.3%). While the results of the measurement of urine protein levels were positive 1 as many as 4 respondents (13.3%), positive 2 as many as 1 respondent (3.4%), and Negative as many as 25 respondents with a percentage (83.3%).

Analysis of iGrav Superconducting Gravity Measurements in Kunming, China, with Emphasis on Calibration, Tides, and Hydrology

Analysis of iGrav Superconducting Gravity Measurements in Kunming, China, with Emphasis on Calibration, Tides, and Hydrology

Tsinghua Scientific Satellite Precise Orbit Determination Using Onboard GNSS Observations with Antenna Center Modeling

The Tsinghua scientific satellite is a Chinese spherical micro satellite for Earth gravity and atmospheric scientific measurements. The accurate orbits of this satellite are the prerequisites to satisfy the mission objectives. A commercial off-the-shelf dual-frequency GNSS receiver is equipped on the satellite for precise orbit determination (POD). The in-flight performances of the receiver are assessed. Regular long-duration gaps up to 50 min are observed in GNSS data, and the typical data availability is about 60–70% each day. The RMS of code noises is 0.24 m and 0.30 m for C1 and P2 codes, respectively. The RMS of fitting residuals of the carrier phase geometry-free L1–L2 combination is 2.4 mm. The GNSS receiver antenna center offsets (ACOs) and antenna center variations (ACVs) maps are estimated using in-flight data for both dual-frequency and single-frequency POD. Significant improvements in POD performances are obtained when the measurement models are updated by using the ACO and ACV maps’ corrections. With the updated measurement model, the RMS of the orbit overlap differences is 1.23 cm in three dimensions for dual-frequency POD, which is reduced by 27%. Meanwhile, two different empirical acceleration types are employed and compared for dual-frequency POD, and the results show that consistency on the 5 cm level is demonstrated for orbit solutions obtained with the updated measurement model. After correcting the ACO and ACV maps, the precision of single-frequency orbit solutions is better than 10 cm, which is improved by 32%. The results indicate that the antenna center modeling can significantly improve the consistency of Tsinghua scientific satellite precise orbits, which will be conducive to the realization of the mission objectives.

Palatalisation can be quantity-sensitive: Dorsal Fricative Assimilation in Liverpool English

This paper shows that the Liverpool English dorsal fricative, derived through the lenition of /k/, is subject to place of articulation assimilation, driven by the preceding vowel. This is similar to the vowel-driven aspects of typical perseverative Dorsal Fricative Assimilation (a type of palatalisation), as found, for example, in the Germanich-Laut~ach-Lautalternation, where (among other things) a preceding front high or mid vowel is followed by the front dorsal [ç], and other vowels are followed by a back dorsal. However, the majority Liverpool English pattern differs from previously described cases of Dorsal Fricative Assimilation in that [ç] only occurs followinglongfront high vowels, while a back dorsal remains after their short congeners. This type of quantity-sensitive pattern in assimilation has not been reported before. We use Centre of Gravity measurements to investigate this pattern of place assimilation, and argue for the use of an innovative normalisation technique for consonant measurements, based on measurements of /k/ aspiration in a linear regression model. We thus both expand the taxonomy of what is known to be possible in phonology and also provide new detail in the description of Liverpool English (including a proposal for the featural analysis of its vowel system).

The Water Cycle of the Baltic Sea Region From GRACE/GRACE-FO Missions and ERA5 Data

The water cycle of the Baltic Sea has been estimated from the Gravity Recovery and Climate Experiment (GRACE) and the GRACE Follow-On satellite time-variable gravity measurements, and precipitation and evaporation from ERA5 atmospheric reanalysis data for the periods 06/2002 to 06/2017 and 06/2018 to 11/2021. On average, the Baltic Sea evaporates 199 ± 3 km3/year, which is overcompensated with 256 ± 6 km3/year of precipitation and 476 ± 17 km3/year of water from land. This surplus of freshwater inflow produces a salty water net outflow from the Baltic Sea of 515 ± 27 km3/year, which increases to 668 ± 32 km3/year when the Kattegat and Skagerrak straits are included. In general, the balance among the fluxes is not reached instantaneously, and all of them present seasonal variability. The Baltic net outflow reaches an annual minimum of 221 ± 79 km3/year in September and a maximum of 814 ± 94 km3/year in May, mainly driven by the freshwater contribution from land. On the interannual scale, the annual mean of the Baltic net outflow can vary up to 470 km3/year from year to year. This variability is not directly related to the North Atlantic Oscillation during wintertime, although the latter is well correlated with net precipitation in both continental drainage basins and the Baltic Sea.

Global Ocean Response to the 5‐Day Rossby‐Haurwitz Atmospheric Mode Seen by GRACE

AbstractA dynamic response of the ocean to surface pressure loading by the well‐known 5‐day Rossby‐Haurwitz mode in the atmosphere has been inferred from limited in situ data, but a global characterization of such response, including details at mid and high latitudes, has been lacking. Here, we explore two products based on inversions of daily Gravity Recovery and Climate Experiment (GRACE) observations to obtain a first quasi‐global look at the associated ocean bottom pressure (pb) signals at 5‐day period. The previously reported in‐phase behavior over the Atlantic basin, seesaw between the Atlantic and Pacific, and westward propagation in the Pacific are all seen in the GRACE‐based pb fields. Correlation analysis points to the Rossby‐Haurwitz surface pressure wave as the main forcing for the observed large‐scale pb anomalies. Other previously unknown features include relatively strong responses in the Southern Ocean and also some shallow coastal regions (e.g., North Sea, East Siberian shelf, and Patagonian shelf), with model experiments indicating they are mainly forced by winds. Inferences on energetics based on GRACE solutions and model results point to decay time scales shorter than the oscillation period, with substantial kinetic energy and dissipation located over a few topographic features in the Southern Ocean. Comparisons with in situ pb and Earth rotation data suggest that the satellite‐based pb estimates at 5‐day period are somewhat more realistic than those of the GRACE de‐aliasing products and comparable to another independent ocean model. Results illustrate the potential of space gravity measurements for examining large‐scale oceanic variability at subweekly periods.

Combining Urinary Biomarker Data From Studies With Different Measures of Urinary Dilution.

Guidance is lacking for how to combine urinary biomarker data across studies that use different measures of urinary dilution, that is, creatinine or specific gravity. Among 741 pregnant participants from four sites of The Infant Development and Environment Study (TIDES) cohort, we assessed the relation of maternal urinary di-2-ethylhexyl phthalate (DEHP) concentrations with preterm birth. We compared scenarios in which all sites measured either urinary creatinine or specific gravity, or where measure of dilution differed by site. In addition to a scenario with no dilution adjustment, we applied and compared three dilution-adjustment approaches: a standard regression-based approach for creatinine, a standard approach for specific gravity (Boeniger method), and a more recently developed approach that has been applied to both (covariate-adjusted standardization method). For each scenario and dilution-adjustment method, we estimated the association between a doubling in the molar sum of DEHP (∑DEHP) and odds of preterm birth using logistic regression. All dilution-adjustment approaches yielded comparable associations (odds ratio [OR]) that were larger in magnitude than when we did not perform dilution adjustment. A doubling of ∑DEHP was associated with 9% greater odds of preterm birth (OR = 1.09, 95% confidence interval [CI] = 0.91, 1.30) when applying no dilution-adjustment method, whereas dilution-adjusted point estimates were higher, and similar across all scenarios and methods: 1.13-1.20 (regression-based), 1.15-1.18 (Boeniger), and 1.14-1.21 (covariate-adjusted standardization). In our applied example, we demonstrate that it is possible and straightforward to combine urinary biomarker data across studies when measures of dilution differ.

Synthesis, spectroscopic and physico-chemical studies of novel pigments derived from Lithol Rubine

PurposeThe pursuit of manufacturing new inks with low financial cost is an urgent economic demand. Thus, the purpose of this paper is to synthesize some new pigments derived from Lithol Rubine (LR) via a successful simple route and to investigate their physicochemical properties for usage in the inks industry.Design/methodology/approachTwo novel pigments were generated during the reaction of LR with Mn(II) and Co(II) salts in ethanolic solutions. The obtained pigments were isolated as solid compounds and characterized through elemental analysis, UV–vis, Fourier transform infrared, 1H NMR spectra, oil absorption, specific gravity, melting point, molar conductivity and magnetic moment measurements. Their dyeing and durability characteristics were examined using American Standard Testing Methods. The synthesized pigments were then applied in inks formulation.FindingsThe printing inks containing the two new pigments (LR–Mn and LR–Co) were compared to (GF 59-606 and GF 59-616), respectively. The results of this study showed that the performance of newly prepared pigments was comparable to that of commercial pigments currently in use in the inks industry.Practical implicationsLR and its new derivative pigments can be used in other different applications such as paper coating, crayon, rubber and paint industries.Originality/valueThe authors designed an efficient synthesis for some novel pigments. The synthesis technique is featured by a short reaction time, high yields and ease of use. The pigments developed would be good and cost-effective substitute for the original commercially available and expensive pigments used in the inks industry.

Investigation of the structural control of a deltaic valley with geophysical methods. The case study of Pineios river delta (Thessaly, Greece)

The current study aims to clarify the structural regime of the deltaic valley of Pineios river (Thessaly, Greece). The structural control of a deltaic area is usually a crucial parameter for its Palaio-geographical evolution and the latter needs to be clear for the contemporary conservation of such a sensitive ecotope environmentally. The investigation of the concealed subsurface tectonic structures was accomplished through the combined interpretation of gravity measurements, VES and TEM soundings. The standard gravity data reduction has been carried out and the residual anomaly was isolated with the contribution of the Fourier filters. The Euler deconvolution has been applied, providing the corresponding depth solutions between 159.8 and 1716.6 m. In the context of the qualitative interpretation, we produced several structural maps (THDR, VDR, Tilt and Theta) in order to enhance the edges of density sources that may reflect fault zones. Severe indications for the delineation of fault zones of the area were provided by these maps. Moreover, 3D density models of the area have been constructed illustrating the subsurface density distribution, up to depths of 3370 m. A main zone of lower densities in the central part of the delta has been revealed, surrounded by three zones of higher densities. Afterwards, the densities of the majority of the existing geological formations were determined with laboratory measurements from geological specimens. Therefore, three geophysical-geological profiles have been constructed, based not only on the gravity modelling but also on the geological interpretation of the geoelectrical layered models from the VES and TEM measurements. In conclusion, concealed and unknown tectonic structures of the Pineios deltaic valley have been identified beneath the surface.