GPR mapping for more than just finding buried materials: A case study in testing ideas about cultural change and community dynamics in 10th century southern Arizona, USA

The Ground Penetrating Radar (GPR) method potentially offers many possibilities for fast and reliable lithostratigraphic sediment models to be developed. From a cognitive point of view, this represents a major simplification and shortening of procedures with which information about sediments can be obtained. And from the point of view of the economy of operations, there can be a significant reduction in costs and time of research in shallow geology and the stratigraphy of areas where unconsolidated clastic sediments are of superficial occurrence. Also noteworthy is the possibility for the results of GPR surveys to be deployed in support of geological mapping, as well as in the shallow exploration of resources and hydrogeological studies.The most major advantage of the GPR method related to the possibility of the structure of forms being observed in full shape. In the absence of large outcrops, geophysical prospection of geomorphological forms is helpful, insofar as we are able to translate the results of geophysical surveys into the actual lithostratigraphic system of sediments building a specific form.Against that background, the research presented in this article forms part of the work to develop radar stratigraphy, as an important support for direct geological research (Huggenberger et al., 1994; Van Overmeeren, 1998; Beres et al., 1999, Overgaard and Jakobsen, 2001; Jakobsen and Overgaard, 2002; Neal, 2004; Lejzerowicz et al., 2014; Żuk and Sambrook Smith, 2015; Lejzerowicz et al., 2018). It also points to the research potential of the GPR method in determining the genesis of form. The discussion on the way kames form has been going on in the literature for years (Niewiarowski, 1959; 1961; Karczewski, 1971; Klajnert, 1978; Jaksa, 2003; Terpiłowski, 2008). The studies presented here do not suffice to allow the matter to be determined comprehensively, even though they do provide for verification of the opinions of previous researchers.The area forming the subject of this article is defined by Niewiarowski (1959) as the dead ice zone because of the characteristic set of forms (dead ice moraines, kames and eskers). Like modern researchers (Terpiłowski, 2008), Niewiarowski points to the importance of sub-Quaternary surface elevations in the formation of cracks in the ice sheet, with this leading on to the formation of kame hills above such elevations. This would also seem to have been one of the reasons for the formation in the mass of ice of lakes whose filling with sediment and melting ice walls took the form of kames.The great advantage of the GPR method lies in its ability to recognise macrostructural sediment patterns in glacilimic forms. This diagnosis allows for the high-probability assessment of the genesis of form, especially in the context of its position being determined in the marginal zone of the ice sheet. Also looking extremely promising is the capacity for the thickness of fine clastic sediments lying on till to be determined using GPR. It allows for the determination of the way in which a given form is rooted.Described as they are in brief only, test results for selected sites serve to confirm the great usefulness of the GPR method in the recognition of shallow lithostratigraphy of clastic sediments. Nevertheless, this should not be the only method used to recognise the geological structure of forms and sediments. Significant interpretation ambiguities mean that the GPR method should act in support of direct lithostratigraphic research, not merely serving as an alternative to it. GPR surveys offer a depiction particularly close to the real one – of sediment present in homogeneous sediments in relation to electrical parameters. Sediments ideal for GPR surveys would for example be fine dry sands or silts – and it is precisely these sediments that built most of the investigated kame forms.

Rail transportation is one of the most efficient ways to transport passengers and products on land. In line with the economic expansion, expand of the railway network is also increasing accordingly. In addition to designing and building, railway maintenance is an equally important task to ensure safety conditions and efficient operation. One of the challenges of railway maintenance is to get a good insight into the track substructure status (ballast, sub-ballast and subgrade). Due to its sensing capabilities, ground penetrating radar (GPR) systems have become an important tool to assess railroad conditions in the past years (Brown and Li, 2017; Ciampoli et al., 2018; Kuo et al., 2018). GPR methods, hardware and signal processing are also continuously evolving to provide with more accurate ways to analyze the track structure. Usually these capabilities have to be evaluated on the field, which is generally a time-consuming and expensive process. As alternative to this, computer simulations are becoming more accessible to users with an always increasing ability to reconstruct realistic measurement methods and soil conditions. The final goal of this study is to obtain realistic simulations of fouled ballast conditions for GPR. Rigid body dynamics simulations have been applied to generate realistic gravel structures using stone particles that were randomly generated. To simulate additional soil layers and dust in the ballast, models for homogeneous soils were used. This geometry was imported into the gprMax simulation software (Warren, 2016; Warren, 2018) to obtain the GPR response.

Ek Leuntie Cave is a karst cave in Meunasah Lhok, Lhoong District, Aceh Besar Regency. This cave is very rare. It has 12 tsunami layers dating back 7500 years. These layers need to be preserved as a paleotsunami geopark in Aceh. However, there are many challenges to developing public facilities in karst areas, such as sinkholes and landslides. Therefore, this study aims to investigate the potential hazards in the area by using the Ground Penetrating Radar (GPR) method at 700 MHz and 250 MHz frequencies. The GPR method is used because of its ability to image shallow subsurface structures with high resolution. The GPR method was used on 7 survey lines around Ek Leuntie Cave. The resulting radargrams are then processed using GPRPy software to clarify the reflection signal. GPR interpretation at 700 MHz and 250 MHz frequencies produces the same radargram at a very shallow depth, but the boundaries between layers are clearer at 700 MHz. Core data from multiple samples supports GPR interpretation. Based on the core data, the compact layer is located in the sandy soil layer, while the less compact layer is located in the old main road before the tsunami layer and in the bedrock. The less compact layer has potential hazards such as subsidence. The area is located in the west to south of the cave. Based on the GPR radargrams obtained, the investigation area is dominated by clay fill, sandy soil, clayey sand and bedrock. The results of the study are expected to be used as a reference for mitigation in the development of the Ek Leuntie Cave Geopark.

<p>The town of Santo Amaro, in the state of Bahia, Brazil, presents a history of contamination, mainly of lead (Pb) originating from the intense activity of metallurgical extraction by the mining company “Plumbum-Mineração e Metalurgia Ltda.” between the years of 1956 and 1993. Over this period, the lead slag was deposited carelessly in the factory area, creating a huge hazardous waste site. Subsequently, the problem increased when this slag was used as the basis for the paving of city streets, gardens, and school yards due to its granular characteristic and good support capacity. However, the ongoing need to remove the street paving for work on the water and sewage networks requires the exposure of the slag, making it a source of active contamination. In this context, the Ground Penetrating Radar (GPR) method was used as a tool to support and guide the evaluation of the existence of anomalous areas associated with the source of local contamination (slag) under the paving. In this work the data was acquired by moving the GPR using the of constant offset technique and a sampling interval of 5 cm between the traces. The shoots and trace records were registered continuously with the use of a calibrated wheel. The results obtained by this study show the potential of applying the GPR method to the environmental characterization of the subsoil of paved streets, making it possible to identify the resistive material contaminants (lead slag) as well as the various layers: paving, soil-slag, and massapê soil. These layers are characterized by distinct reflection patterns. The first observed reflection pattern has high amplitude with horizontal and continuous reflectors, which correspond to a characteristic pattern of urban street paving. The second reflection pattern is characterized by reflectors with amplitude variations (horizontal and inclined, continuous and discontinuous), which indicate the heterogeneity of the medium and corresponds to the soil pattern mixed with the resistive slag material. The third reflection pattern is characterized by low amplitude with chaotic and totally discontinuous reflectors, and occurs just below the second reflection pattern. This pattern of reflection marks the region in which the electromagnetic GPR signal is absorbed by the medium. This absorption is an effect of the attenuation of the electromagnetic signal by the presence of electrically conductive layers of the characteristic massapê soil (clayey to very clayey) of the study area. GPR data also enabled the identification of reflectors associated with anthropogenic interferences (manholes, train lines, pipelines, etc.). Borehole samples confirmed the existence of the contaminant (lead slag). Anomalous concentrations of heavy metals, mainly lead, were observed in the locations indicated by geophysical results using the GPR method, showing the importance of the use of geophysics in environmental characterization programs.</p>

Ground penetrating radar and shear-wave reflection methods were used to characterize the shallow subsurface. Both methods were compared at a site in south western Sweden. The site, which consists of a 150 m long profile, was chosen based on existing site information from previous studies. The shallow subsurface consists mainly of sediments of sand and clay. Ground penetrating radar methods, using common-offset and multi-offset techniques, in combination with common midpoint processing, were compared regarding resolution and depth penetration. It is shown that the latter strategy provides more distinct reflections and allows a deeper range of interpretable reflectors. The shear-wave reflection method images overlapping and deeper parts of the section which are below the depth range resolved by the radar waves. The study shows that by combining information from ground penetrating radar and shear-wave reflection surveys, a more complete analysis of subsurface geology can be conducted. Also in conductive environments, the shear-wave reflection method offers a possible alternative to ground-penetrating radar.

For effective commercial development of deposits, an increase in the information content of operational exploration is required. In recent years, the range of methods used to obtain complete and reliable information about the structure and properties of the rock mass of a developed field include remote methods of high-frequency electrical prospecting, in particular, the ground penetrating radar (GPR) method. The paper presents a methodological experience in the interpretation of GPR data of sandy river sediments based on the identification of radar facies. In the considered area, four types of radar facies have been identified that characterize the structure of sandy deposits and the morphology of the river bed. The criteria for identifying radar facies were used to analyze wave patterns of loose sediments in a sand and gravel pit and a placer gold deposit. Experimental GPR investigations are presented by data from a sandy-gravel pit (Warsaw, Poland) and from a placer gold deposit (Yakutia, Russia). As an example, a GPR section along the Paplin quarry and its interpretation, with the identification of GPR facies, is presented. A cross-sectional GPR profile of the dredging landfill is considered for the placer gold deposit. The analysis of the wave pattern was carried out, geological boundaries were highlighted. Based on the interpretation results, the characteristics of the rocks were given. It was noted that according to the GPR data, it is possible to identify zones of uplift of bedrock, which can affect the course of the dredge. As a result of using GPR in a swampy area where drilling was impossible, a deep three-layer section was obtained. The presented results of the successful use of GPR investigations and methodological approaches in the interpretation of data, show the promise of using the GPR method in assessing mining and geological conditions, in particular, placer deposits. At the same time, the efficiency of obtaining data can further contribute to the optimization of technology and increase the efficiency of field development.

There have been several recent reports of collapsed roads at the various locations throughout the Bangkok metropolitan area. Most of the problems are caused by improper construction of utility networks and poor rehabilitation work. Ground penetrating radar (GPR) technique was selected to investigate the potential presence of subsurface voids under the road surface. In geotechnical and structural applications, GPR is an excellent tool for being able to image steel reinforcing bars, voids and tendon ducts in concrete structures and, more relevantly to this study, voids beneath concrete roads. The objective of this study was to survey the area for potential voids that might exist under the road surface using ground penetrating radar technique. The GPR survey campaign was divided into two stages, which were the preliminary and detailed surveys. The objective of the preliminary survey was to quickly survey the area for potential voids that might exist under the road surface and subsequently a more detailed survey of those areas was performed to confirm the existence and determined the lateral and vertical extension of the potential void(s) identified in the preliminary GPR survey. The GPR data were collected with 400 MHz antenna mounted on a survey cart. Several void-like anomalies were detected from the GPR data and these selected anomalies were drilled to confirm the existence of a void. However, some GPR anomalies were found not to be voids, and mostly came from areas of past road maintenance or manholes with a hidden cover (asphaltic concrete overlay). One example of a large void under the road surface was detected in this study, being clearly seen in the GPR data and then confirmed by drilling. The GPR method was successfully used for void detection under a main road in Bangkok city. In this study the 400 MHz ground-coupled antenna was used to image potential subsurface voids and these were then confirmed (or not) by drilling boreholes in that area through the road surface. In the example shown in this report as a case study, the identified void was approximately 4 m long, 2 m wide and 1.5 m deep. As a result of its discovery it was subsequently treated by backfilling and a new road surface was then constructed.

Abstract. Current estimates of carbon (C) storage in peatland systems worldwide indicate that tropical peatlands comprise about 15% of the global peat carbon pool. Such estimates are uncertain due to data gaps regarding organic peat soil thickness, volume and C content. We combined a set of indirect geophysical methods (ground-penetrating radar, GPR, and electrical resistivity imaging, ERI) with direct observations using core sampling and C analysis to determine how geophysical imaging may enhance traditional coring methods for estimating peat thickness and C storage in a tropical peatland system in West Kalimantan, Indonesia. Both GPR and ERI methods demonstrated their capability to estimate peat thickness in tropical peat soils at a spatial resolution not feasible with traditional coring methods. GPR is able to capture peat thickness variability at centimeter-scale vertical resolution, although peat thickness determination was difficult for peat columns exceeding 5 m in the areas studied, due to signal attenuation associated with thick clay-rich transitional horizons at the peat–mineral soil interface. ERI methods were more successful for imaging deeper peatlands with thick organomineral layers between peat and underlying mineral soil. Results obtained using GPR methods indicate less than 3% variation in peat thickness (when compared to coring methods) over low peat–mineral soil interface gradients (i.e., below 0.02°) and show substantial impacts in C storage estimates (i.e., up to 37 MgC ha−1 even for transects showing a difference between GPR and coring estimates of 0.07 m in average peat thickness). The geophysical data also provide information on peat matrix attributes such as thickness of organomineral horizons between peat and underlying substrate, the presence of buried wood, buttressed trees or tip-up pools and soil type. The use of GPR and ERI methods to image peat profiles at high resolution can be used to further constrain quantification of peat C pools and inform responsible peatland management in Indonesia and elsewhere in the tropics.

Two examples were considered in this presentation; detection of cavities in limestone, delineation of boundaries of an archeological remain using Ground Penetrating Radar (GPR) method and affect of the trees on the GPR data. The GPR method has been successfully applied to detect and map underground cavities in Limestone in a reservoir area of a dam being built in southeast Turkey. The study area divided into nine segments each of which was 100m wide. Total study area was 696x100 m2. Ground Penetrating Radar data were collected on parallel profiles of 2 m interval. Station interval set 0.5 m on each profile. Following the data processing, new amplitude-color range and opacity function were constructed for 3D visualization. Finally cavity locations on x-y coordinates and their depths determined on the 3D Ground Penetrating Radar data blocks and marked on the map. The result of the drilling of some locations showed that the ratio of success was % 95. In the second example, the GPR method was used to search the archeological remains in 20x10 m area northern part of the Turkey. After the data process steps similar to those given above, remains of the castle wall were found.

PreviousNext No Access19th International Conference on Ground Penetrating RadarDiagnosis of the culvert lining based on the integration of GPR and LiDARAuthors: Yanfeng ZhouTess LuoYanfeng ZhouShenzhen UniversitySearch for more papers by this author and Tess LuoShenzhen UniversitySearch for more papers by this authorhttps://doi.org/10.1190/gpr2022-095.1 SectionsAboutPDF/ePub ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinked InRedditEmail Abstract During operation, water delivery culverts may suffer from various defects such as cracks, delamination, cavities, and looseness. It is of vital importance to inspect the health condition of subsurface culverts, to maintain the safe operation of hydrology infrastructure. Non-destructive testing (NDT) methods that can inspect the culvert structure without excavation. However, since each NDT method has its own advantage and disadvantage, a defect cannot be determined by a single measurement. This study proposed a hybrid method to diagnose the culvert lining by combining Ground Penetrating Radar (GPR) and light detection and ranging (LiDAR). Firstly, LiDAR is applied to fast scan the lining surface to localize cracks and seepages from the surface. Then GPR survey is conducted on the sidewall of the culvert, to image and validate whether there is separation or voids occurring at these abnormal areas. Finally, a diagnosis with more confidence can be obtained by interpreting data from two techniques. To improve the accuracy of GPR interpretation, GPRMAX 3.0 was used to numerically modelled the GPR responses of typical culvert lining defects (cracks and layer separation). A case study was conducted in Shenzhen, China. The acquired GPR data was analyzed based on the numerical simulation. The inspection results of GPR and LiDAR, in terms of defect location, size, and severity, were found consistent. When a defect is extracted from both GPR and LiDAR measurements, it is more serious that needs proper maintenance. The study proves the feasibility of inspecting the culvert lining from both surface and subsurface. Keywords: ground-penetrating radar (GPR), hydrology, imaging, time-domain, electromagnetic Permalink: https://doi.org/10.1190/gpr2022-095.1FiguresReferencesRelatedDetails 19th International Conference on Ground Penetrating RadarISSN (online):2159-6832Copyright: 2022 Pages: 166 publication data© 2022 Published in electronic format with permission by the Society of Exploration GeophysicistsPublisher:Society of Exploration Geophysicists HistoryPublished Online: 13 Oct 2022 CITATION INFORMATION Yanfeng Zhou and Tess Luo, (2022), "Diagnosis of the culvert lining based on the integration of GPR and LiDAR," SEG Global Meeting Abstracts : 71-74. https://doi.org/10.1190/gpr2022-095.1 Plain-Language Summary Keywordsground-penetrating radar (GPR)hydrologyimagingtime-domainelectromagnetic PDF DownloadLoading ...

Electrical Resistivity Imaging (ERI) and Ground-Penetrating Radar (GPR) methods were utilized in this study to identify soil profiles around Necatibey Subway Station of Kizilay–Cayyolu metro line, Ankara, Turkey. The Necatibey Metro Station is located within the alluvial deposits of Dikmen stream and the so-called Ankara clay. At the metro station, a number of boreholes were drilled. However, due to the spacing of the boreholes the boundary between alluvium and Ankara clay deposits could not be separated precisely. Thus, in this study, ERI and GPR methods were utilized to distinguish soil types at the study area. GPR measurements were taken from a total of 14 profiles and total length of the profiles was about 320 m. For every ERI measurement section, Schlumberger Dipole–Dipole, Dipole–Dipole, Schlumberger and Wenner arrays were used. Results from the geophysical measurements identified that the fill materials are underlain by the Dikmen stream channel deposits, which consist of silty clay and gravelly sand units. The study also shows that the Dikmen stream channel deposits are underlain by the Ankara clay unit. The meaningful range of resistivity values was between 1 and 15 Ωm, and the GPR signals were strong in sandy units while they attenuated in clayey environments. Based on borehole logs, ERI and GPR data, three-dimensional lithological subsurface model of the survey area was constructed. The resultant three-dimensional diagrams may serve engineers as a practical tool during different construction stages, groundwater–surface water interactions within short and long term, and probable remedial measures.

At this investigation, it is aimed to display the internal structure including intensely landing points of planes (observed fracture, joint and deformation from surface) at Erzincan Airport with the ground penetrating radar (GPR) method. To view whether the observed deterioration at the surface continues under the landing field horizontally and vertically or not, at the observed fracture-joints part of study area GPR data were collected by using 800 MHz center frequency antenna at 20 lines. Measuring range was selected 1 m and the lines were selected 18 m long to parallel each other. After applying the standard data processing steps to obtained data, 2D and 3D views were determined. When these views analyzed; generally high quality landing space conditions are monitored, there are attenuation parts of electromagnetic waves locally and especially observed joints at 2.7 and 15 meters from surface was determined to continue at horizontal and vertical extension of the acquired GPR views. It was suggested to carry out maintenance to relevant institution.

Two examples were considered in this presentation; detection of cavities in limestone, delineation of boundaries of an archeological remain using Ground Penetrating Radar (GPR) method and affect of the trees on the GPR data. The GPR method has been successfully applied to detect and map underground cavities in Limestone in a reservoir area of a dam being built in southeast Turkey.

No previous work with the Ground Penetrating Radar (GPR) method has been reported for the Middle Amazon Basin. The utility of the GPR method in the deeply weathered soils of the humid tropics was tested at six different sites within a radius of 200 kID of Manaus, Brazil. The objective was to determine if it was feasible to use the GPR method even though clays and very moist conditions dominate in this region. Results showed that all soils, including massive clays, have such low conductivity that GPR penetration is far better than in temperate climates. Excellent penetration, at times exceeding 12 meters with 100 MHz antennas, was achieved at all sites. Lateritic bands caused very strong reflections where present. In clay dominated areas, animal burrows, insect galleries, and tree roots and casts were interpreted as sources of individual localized reflections. Several kID of profile were recorded with a floating antenna on the Amazon River, and showed large scale (60-100 meter wavelength) structures of the bottom and sub-bottom. GPR is an excellent tool to use for shallow investigations in this region.

The Hagia Sophia Museum has an important place in both Byzantine and Turkish history, which was constructed by Emperor Justinian in 532 – 537 AD. After get over many large earthquakes and disasters, the Hagia Sophia Museum has maintained its existence until nowadays with repairs and renovations at various times. In this study, the crack in the Gallery floor ground and the condition of the vaults, which are located between Gallery floor and the main hall of the Hagia Sophia Museum were investigated by GPR (Ground Penetrating Radar) method with 1 GHz HF (High Frequency) antenna. The obtained data revealed quite clearly, the deterioration in the vault structure located under the Gallery floor. In the same time it has also revealed the work to strengthen the reinforced metal system made at this level. GPR results showed that, the strengthening work larger than the strengthening work mentioned in many older sources at the Hagia Sophia Museum, and these new results contribute to the future static studies. After this successful GPR study, the new project on the walls and the basements of the Hagia Sophia Museum was started with GPR and GPR-CX (Ground Penetrating Radar – Concrete Exploration) methods.