scholarly journals Использование геофизических методов для изучения криогенного состояния пород разрабатываемых золоторудных месторождений Магаданской области

2021 ◽  
pp. 30-39
Author(s):  
I. M. Khasanov ◽  
◽  
V. N. Volkov ◽  
◽  
Keyword(s):  
Electrical Resistivity ◽  
High Efficiency ◽  
Geophysical Methods ◽  
Induced Polarization ◽  
Gold Deposits ◽  
Permafrost Zone ◽  
Magadan Oblast ◽  
Field Development ◽  
Permafrost Rocks ◽  
Development Processes

The authors consider the problem of applicability and sensitivity of methods of ground geophysics for studying the state of rock massifs in the permafrost zone. Using the example of gold deposits in Magadan Oblast, they study and analize peculiarities of changes in the values of electrical resistivity and induced polarization of soils, depending on their cryogenic state. Sufficiently high efficiency of geophysical methods in distinguishing thawed, seasonally thawed, locally frozen, and permafrost rocks is substantiated. The research results are recommended for optimizing field development processes in various engineering and geological settings.

scholarly journals Induced Polarization as a Proxy for CO2-Rich Groundwater Detection—Evidences from the Ardennes, South-East of Belgium

Water ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1394
Author(s):  
Agathe Defourny ◽  
Frédéric Nguyen ◽  
Arnaud Collignon ◽  
Patrick Jobé ◽  
Alain Dassargues ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Land Surface ◽  
Geophysical Methods ◽  
Fracture Network ◽  
Induced Polarization ◽  
Resistivity Tomography ◽  
Near Surface ◽  
Future Supply ◽  
The Time Domain ◽  
Groundwater Springs

CO 2 -rich mineral groundwaters are of great economic and touristic interest but their origin and circulation paths in the underground are often poorly understood. A deeper understanding of the system plumbery and the development of non—to minimally—invasive near-surface geophysical methods for the prospection of potential productive areas is therefore of great interest to manage future supply. The objective of this contribution is to assess the ability of the time-domain induced polarization (TDIP) method, combined with the electrical resistivity tomography (ERT) method, to make the distinction between CO 2 -rich groundwater from non-gaseous groundwater. Three combined ERT/TDIP tomographies were performed above known uplift zones in the south-east of Belgium where thousands of CO 2 -rich groundwater springs exist. On all profiles, important contrasts in both electrical resistivity and chargeability distributions were observed in the vicinity of the upflow zone, also reflected in the normalized chargeability sections computed from the measured data. Low resistivity vertical anomalies extending in depth were interpreted as a saturated fracture network enabling the upflow of deep groundwater to the surface. High chargeability anomalies appearing directly close to the CO 2 -rich groundwater springs were inferred to metallic oxides and hydroxides precipitation in the upper part of the aquifer, linked to pressure decrease and changing redox conditions in the up-flowing groundwater approaching the land surface. The combined interpretation of electrical resistivity and induced polarization datasets provides a very promising method for a robust prospection of CO 2 -rich groundwater.

Electrical signature of CO2-rich mineral groundwater systems - Application in the Ardennes, South-East of Belgium

2020 ◽  
Author(s):  
Agathe Defourny ◽  
Thomas Kremer ◽  
Arnaud Collignon ◽  
Patrick Jobé ◽  
Alain Dassargues ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Land Surface ◽  
Geophysical Methods ◽  
Induced Polarization ◽  
Fractured Aquifer ◽  
Near Surface ◽  
Polarization Tomography ◽  
Future Supply ◽  
Uplift Zone ◽  
Drilling Operations

<p>CO<sub>2</sub>-rich mineral groundwaters have been exploited for centuries for both bottling and thermal activities. The detection and understanding of productive areas is therefore of great interest to manage future supply in a sustainable way. CO<sub>2</sub>-rich mineral water systems are complex since they usually involve an intricated network of water bearing fractures enabling the uplift of CO<sub>2</sub>-rich groundwater to the surface, a process that is still poorly understood. Geophysical prospection is crucial to detect potential uplift zones and to address corresponding uncertainties before drilling operations.</p><p>In this context, non - to minimally - invasive near-surface geophysical methods can prove to be efficient. The objective of this contribution is to assess the ability of the induced polarization method, combined with the electrical resistivity technique, to make the distinction between CO<sub>2</sub>-rich groundwater from non-gaseous groundwater.</p><p>Several combined electrical resistivity and induced polarization tomography profiles were performed in the Ardennes (Belgium) where thousands of CO<sub>2</sub>-rich groundwater springs are observed. The profiles were all set immediately above known uplift zones. Inversion results were consistent between all profiles and important contrasts in both electrical resistivity and chargeability distributions in the vicinity of the uplift zone were observed, which were also reflected in the normalized chargeability sections computed on the basis of the measured data.</p><p>Low resistivity vertical contrasts extending in depth were observed and interpreted as saturated fractures enabling the uplift of deep groundwater to the surface. In addition, high chargeability anomalies appeared directly close to the CO<sub>2</sub>-rich groundwater resurgence. Those anomalies are thought to be associated to the presence of metallic oxides and hydroxides, as a result of dissolved metallic species precipitation in the upper part of the fractured aquifer due to the pressure decrease and change in redox conditions in up-flowing groundwater towards the land surface.</p><p>We conclude that the combined interpretation of electrical resistivity and induced polarization datasets is a very promising method for a more robust prospection of naturally sparkling groundwater.</p>

Prospecting alpine permafrost with Spectral Induced Polarization in different geomorphological landforms

2020 ◽  
Author(s):  
Theresa Maierhofer ◽  
Timea Katona ◽  
Christin Hilbich ◽  
Christian Hauck ◽  
Adrian Flores-Orozco
Keyword(s):  
Electrical Resistivity ◽  
Thermal State ◽  
Geophysical Methods ◽  
Induced Polarization ◽  
Swiss Alps ◽  
High Mountain ◽  
Monitoring Site ◽  
European Alps ◽  
Mountain Permafrost

<p>Permafrost regions are highly sensitive to climate changes, which has significant implications for the hydrological regimes and the mechanical state of the subsurface leading to natural hazards such as rock slope failures. Therefore, a better understanding of the future evolution and dynamics of mountain permafrost is highly relevant and monitoring of the thermal state of permafrost has become an essential task in the European Alps. Geophysical methods have emerged as well-suited to support borehole data and investigate the spatial distribution and temporal changes of temperature and the degradation of permafrost. In particular, electrical resistivity tomography (ERT) has developed into a routine imaging tool for the quantification of ice-rich permafrost, commonly associated with a significant increase in the electrical resistivity. However, in many cases, the interpretation of the subsurface electrical resistivity is ambiguous and additional information would improve the quantification of the ice content within the subsurface. Theoretical and laboratory studies have suggested that ice exhibits a characteristic induced electrical polarization response. Our results from an extensive field programme including many morphologically different mountain permafrost sites now indicate that this IP response may indeed be detected in the field suggesting the potential of the Induced Polarization (IP) method to overcome such ambiguities. We present here Spectral IP (SIP) mapping results conducted over a broad range of frequencies (0.1-225 Hz) at four representative permafrost sites of the Swiss-, Italian- and Austrian Alps. The mapping results have been used to install long-term permafrost monitoring arrays for a better understanding of subsurface variations associated to climate change. All SIP study sites are located at elevations around 2600 - 3000 m and include comprehensive geophysical and temperature data for validation. We focus on the spatial characterization of each site to address different research questions: to (i) reproduce and improve the mapping of the spatial permafrost extent inferred from previous investigations in the Lapires talus slope,Western Swiss Alps, to (ii) improve the geophysical characterization of the Sonnblick monitoring site located in the Austrian Central Alps, to (iii) determine the transition between permafrost and non-permafrost at the Schilthorn site, Bernese Alps, Switzerland, and to (iv) find the best-suited location for a SIP monitoring profile and conduct year-round measurements at the Cime Bianche site, Western Italian Alps. Our various field applications demonstrate the potential of the IP method for characterizing and monitoring permafrost systems in high-mountain environments.</p>

Geotechnical investigation through SP, Electrical Resistivity and GPR geophysical methods

Geotecnia ◽  
2016 ◽  
Vol 137 ◽  
pp. 141-155
Author(s):  
Herson Oliveira da Rocha ◽  
◽  
Lúcia Maria Costa e Silva ◽  
João Andrade dos Reis Júnior ◽  
◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Geophysical Methods ◽  
Geotechnical Investigation

scholarly journals Characterization of a Shallow Coastal Aquifer in the Framework of a Subsurface Storage and Soil Aquifer Treatment Project Using Electrical Resistivity Tomography (Port de la Selva, Spain)

2021 ◽  
Vol 11 (6) ◽  
pp. 2448
Author(s):  
Alex Sendrós ◽  
Aritz Urruela ◽  
Mahjoub Himi ◽  
Carlos Alonso ◽  
Raúl Lovera ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Water Reuse ◽  
Electrical Resistivity Tomography ◽  
Groundwater Modeling ◽  
Geophysical Methods ◽  
Soil Aquifer Treatment ◽  
Modeling Tools ◽  
Resistivity Tomography ◽  
Implicit Modeling ◽  
The Difference

Water percolation through infiltration ponds is creating significant synergies for the broad adoption of water reuse as an additional non-conventional water supply. Despite the apparent simplicity of the soil aquifer treatment (SAT) approaches, the complexity of site-specific hydrogeological conditions and the processes occurring at various scales require an exhaustive understanding of the system’s response. The non-saturated zone and underlying aquifers cannot be considered as a black box, nor accept its characterization from few boreholes not well distributed over the area to be investigated. Electrical resistivity tomography (ERT) is a non-invasive technology, highly responsive to geological heterogeneities that has demonstrated useful to provide the detailed subsurface information required for groundwater modeling. The relationships between the electrical resistivity of the alluvial sediments and the bedrock and the difference in salinity of groundwater highlight the potential of geophysical methods over other more costly subsurface exploration techniques. The results of our research show that ERT coupled with implicit modeling tools provides information that can significantly help to identify aquifer geometry and characterize the saltwater intrusion of shallow alluvial aquifers. The proposed approaches could improve the reliability of groundwater models and the commitment of stakeholders to the benefits of SAT procedures.

Electrical Resistivity and Induced Polarization signatures to delineate the near-surface aquifers contaminated with seawater invasion in Digha, West-Bengal, India

CATENA ◽  
2021 ◽  
Vol 207 ◽  
pp. 105596
Author(s):  
Prashant Kumar ◽  
Prarabdh Tiwari ◽  
Anand Singh ◽  
Arkoprovo Biswas ◽  
Tapas Acharya
Keyword(s):  
Electrical Resistivity ◽  
West Bengal ◽  
Induced Polarization ◽  
Near Surface

Music Material Development Techniques (Lectures in «Principles of Music Analysis») 

2020 ◽  
pp. 53-69
Author(s):  
Р.Х. Лаул
Keyword(s):  
Final Section ◽  
High Efficiency ◽  
Music Analysis ◽  
Detailed Examination ◽  
Musical Composition ◽  
Musical Form ◽  
Musical Work ◽  
Saint Petersburg ◽  
Material Development ◽  
Development Processes

Настоящий материал продолжает серию публикаций лекций Рейна Лаула по анализу музыки в Санкт-Петербургской (Ленинградской) консерватории. Шестая лекция завершает обзор приемов разработочного развития музыкального материала. В нее вошли шесть из двадцати пяти приемов в авторской классификации (эпизодическая тема, производная тема, варьирование, полифонические варианты, приемы подвижного контрапункта, полифонические структуры), способствующей систематизации разработочных процессов. В поле зрения автора включены неспецифически сонатные способы преобразования музыкального материала, благодаря чему сонатность предстает в гибком и взаимодополняющем взаимодействии с иными принципами формообразования. Особое внимание уделено специфике применения полифонических средств развития музыкального материала в контексте сонатного формообразования. В ходе детального рассмотрения финала симфонии В. А. Моцарта Юпитер оказываются тесно связанными технологический, композиционно-драматургический и стилевой аспекты становления музыкальной формы. Заключительный раздел, обобщающий содержание лекции в целом, содержит пример практического применения предлагаемой автором методологии. Тем самым доказывается ее целесообразность и высокая эффективность как в аспекте анализа интонационной драматургии музыкального произведения, так и в достижении главной аналитической цели в формировании объективного представления о содержательной сути каждого этапа в развёртывании музыкальной композиции. This material continues the series of publications of R. H. Lauls lectures on music analysis at the Leningrad (Saint Petersburg) Rimsky-Korsakov State Conservatory. The sixth lecture concludes the review of techniques for developing musical material. It discusses six of the twenty-five techniques in the authors classification (episodic theme, derived theme, variation, polyphonic variants, mobile counterpoint techniques, polyphonic structures), which contributes to systematization of the development processes. The authors field of view includes non-specific Sonata methods of transforming the musical material, so that sonateness appears in a flexible and complementary interaction with other principles of formation. Special attention is paid to the specifics of using polyphonic means of developing musical material in the context of Sonata formation. The detailed examination of the finale of Mozarts Symphony Jupiter, shows that technological, compositional, dramatic, and stylistic aspects of the formation of a musical form appear to be closely related. The final section summarizing the content of the lecture as a whole contains an example of practical application of the methodology proposed by the author, proving its expediency and high efficiency not only in the aspect of analyzing the intonation drama of a musical work, but also of achieving the main analytical goal to form a reasoned judgment about the content of each stage in the deployment of a musical composition.

Investigating the Effective Resistivity of Reinforced Concrete Waste Storage Tanks at the Hanford Site

Geophysics ◽  
2021 ◽  
pp. 1-50
Author(s):  
Allan Haas ◽  
Dale F. Rucker ◽  
Marc T. Levitt
Keyword(s):  
Electrical Resistivity ◽  
Reinforced Concrete ◽  
Geophysical Methods ◽  
Underground Storage ◽  
Storage Tanks ◽  
Hanford Site ◽  
Underground Storage Tanks ◽  
Effective Resistivity ◽  
Geophysical Surveys ◽  
Wide Range

Industrialized sites pose challenges for conducting electrical resistivity geophysical surveys, as the sites typically contain metallic infrastructure that can mask electrolytic-based soil and groundwater contamination. The Hanford site in eastern Washington State, USA, is an industrialized site with underground storage tanks, piping networks, steel fencing, and other potentially interfering infrastructure that could inhibit the effectiveness of electrical resistivity tomography (ERT) to map historical and monitor current waste releases. The underground storage tanks are the largest contributor by volume to subsurface infrastructure and can be classified as reinforced concrete structures with an internal steel liner. Directly measuring the effective value for the electrical resistivity of the tank, i.e., the combination of individual components that comprise the tank’s shell, is not reasonably possible because they are buried and dangerously radioactive. Therefore, we indirectly assess the general resistivity of the tanks and surrounding infrastructure by developing synthetic ERT models with a parametric forward modeling study using a wide range of resistivity values from 1×10−6 to 1×104 ohm-m, which are equivalent to steel and dry rock, respectively. The synthetic models used the long-electrode ERT method (LE-ERT), whereby steel cased metallic wells surrounding the tanks are used as electrodes. The patterns and values of the synthetic tomographic models were then compared to LE-ERT field data from the AX tank farm at the Hanford site. This indirect method of assessing the effective resistivity revealed that the reinforced concrete tanks are electrically resistive and the accompanying piping infrastructure has little influence on the overall resistivity distribution when using electrically based geophysical methods for characterizing or monitoring waste releases. Our findings are consistent with nondestructive testing literature that also shows reinforced concrete to be generally resistive.

scholarly journals Empirical Correlation between Geotechnical and Geophysical Parameters in a Landslide Zone (Case Study: Nargeschal Landslide)

2018 ◽  
Vol 22 (3) ◽  
pp. 195-204 ◽  
Author(s):  
Sadegh Rezaei ◽  
Issa Shooshpasha ◽  
Hamed Rezaei
Keyword(s):  
Electrical Resistivity ◽  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Geophysical Methods ◽  
Field Investigation ◽  
Least Square ◽  
Geotechnical Investigations ◽  
Geophysical Techniques ◽  
Landslide Zone

Today, geotechnical and geophysical techniques are used for landslide evaluation. Geotechnical methods provide accurate data, but are time consuming and costly. Geophysical techniques, however, are fast and inexpensive, yet their accuracy is lower than that of the geotechnical methods. Therefore, simultaneous use of geotechnical and geophysical methods provides a suitable solution for landslide evaluation. Availability of geotechnical and geophysical data makes it possible to investigate correlation between different parameters. Correlating geotechnical and geophysical parameters ends up lowering field investigation costs and enhancing subsurface survey speed in a landslide zone. In the present study, in order to evaluate Nargeschal landslide in Iran, ambient noise measurement, ERT survey, and geotechnical investigations were used. Once finished with data processing, the data obtained from geotechnical and geophysical investigations were correlated. These included SPT-N – electrical resistivity, soil moisture content – electrical resistivity, and SPT-N – shear wave velocity correlations. The correlations were examined using two methods, namely Spearman’s coefficient test and least square regression analysis. The results obtained from the two methods were in good agreement with one another. The correlations obtained in this study were of moderate to very strong strength and fell in the range of the results of previous studies. Investigation of the results indicated significant influences of ground water on electrical resistivity and soil stiffness on shear wave velocity. Results of this study can be used for soil classification and determination of mechanical and seismic characteristics of soil across various areas.

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